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RAID!!! Is it a a good idea for PCs?

kryystkryyst Ontario, Canada
edited Aug 2011 in Hardware
I just need to say this - take it for what you will.

Stop putting raids in your home systems unless you understand how they work, understand the risk/rewards of using them and more importantly understand how to recover them when they fail. Oh and they will fail, every raid fails.

Also if you really want to run raid, make sure you are backing up whatever is on the raid. Then when the raid fails (and it will fail) you can kill the raid, rebuild it and recover from your backup. Without having to mess around trying to rebuild a raid.

One more thing. If you are running a raid (again home systems) make sure you are running a seperate raid controller and doing hardware raid also. Onboard raid controllers suck for 2 reasons. One if the controller fails you can replace the controller not the whole motherboard and secondly they are typically more reliable and come with better tools to repair your raid - when it fails. If you are running software raid, well god help you.

Raid types. If you feel the need to run raid don't run raid 0. Simple as that. If you want reliability run Raid 1, if a drive fails basically no biggy. But know that raid 1 is primarily for redundancy and not speed. Raid 5, rather popular put in 3 (or more) drives loose 25% of your space and gain almost no benefit on a home computer because guess what - you are the only person using it so the data access is rather singular. You don't have a whole tone of multiple read/writes in the cue.

Pleas people I know I'm ranting but it's a lesson that many need to learn. Raids are ideal in the business world where you have high volume, highly accessed data stores they are also running on server class machines that are designed to do it.

Raid on your home computer not worth it.

Rant off.
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Comments

  • primesuspectprimesuspect HumanGarbageDisposal Detroit, MI Icrontian
    edited Feb 2008
    I think motherboard manufacturers putting raid controllers onboard is a travesty. I agree with everything you said 100%, Kryyst
  • LeonardoLeonardo Eagle River, Alaska Icrontian
    edited Feb 2008
    Kryyst, you are preaching to the choir, but the preaching is appropriate and must go on! So many of us more experienced PC nuts here have been warning against RAID, especially RAID 0 for years. Every day there is another help-needed thread begging for assistance to recover files from a FUBARed array. Everyone is convinced that RAID will turn their PC into a rocket ship.

    I understand, I did RAID 0 for several years. I quit about five years ago. GOOD RIDDANCE. That rocket ship never did dock at my PC space port.
  • kryystkryyst Ontario, Canada
    edited Feb 2008
    It was the recent rash of raid issues in the last couple weeks that drove me to the need to rant. I mean anyone reading through this forum, should by now have picked up on it that Raid can lead to grief. But that golden ticket of speed so many people think lies in setting up a Raid just doesn't exist.

    Yes Raid can be faster. But the strength of raid lies in multiple simultaneous r/w. Which is crucial on a network. On a home system even if your multi-tasking, a lot, the speed benefit is just not there. The risk of it, far outweighs the reward. It's as simple as that.

    You want a speed boost take the money you are wasting on redundant drives, buy more ram, put in a better graphics card, don't bother with putting the drive in a raid just use it for backups. Whatever you do, there are much better ways to make a system better then spending it on a raid.
  • LeonardoLeonardo Eagle River, Alaska Icrontian
    edited Feb 2008
    It was the recent rash of raid issues in the last couple weeks that drove me to the need to rant.
    That rash of problems is constant. I'd personally like to see a sticky thread at the top of the Storage forum: "RAID, Just Say No"
  • WinfreyWinfrey waddafuh Missouri Icrontian
    edited Feb 2008
    ooomph tis oomph tis... oh wait RAID not Rave :(

    I was running RAID 0 on my system for awhile under the pretense that it improved performance of the drives. Luckily I had no problems running it but eventually the fear of having my RAID fail and lose all of my stuff made me nervous enough to backup my data and remove my RAID.

    After seeing all the threads about RAID failure and people using RAIDs that really don't know what they are getting into, should ascribe to kryyst's advice.

    QFT:cool2:
  • EssoEsso Stockholm, Sweden
    edited Feb 2008
    What's the point with computers, if we can't run into problems sometimes.

    It releases a lot of build up stress .. :)
    and we feel great after we fixed it.

    Even if we are responsible for the problem ...
    But that, we don't want to hear about :bigggrin:
  • SnarkasmSnarkasm 's-Hertogenbosch, The Netherlands Icrontian
    edited Feb 2008
    The key is actually knowing what you're doing. I, for instance, run a RAID 0 on a pair of Raptors, and keep a biweekly backup on a second drive. Am I so wrong, such a terrible person? I understand the risks, take efforts to protect against them, and felt like doing it all the same.

    All I'm saying is, isn't education a better answer than blatant denial? Just telling somebody "you don't need this" rather than explaining its risks and letting them decide what the heck they want to do?
  • LeonardoLeonardo Eagle River, Alaska Icrontian
    edited Feb 2008
    What's the point with computers, if we can't run into problems sometimes. It releases a lot of build up stress .
    1) Sure, RAID can be a fun toy - for a while, until for some unknown reason the array is corrupted.
    2) The risk usually outweighs the benefits - tangible or emotional (the fun)
    The key is actually knowing what you're doing. I, for instance, run a RAID 0 on a pair of Raptors, and keep a biweekly backup on a second drive.
    1) Backup is the WAY to go (whether RAID or single drive).
    2) "Actually knowing what you're doing." Obviously. Still though - twice the number of cables; twice the number of disks; essentially no tolerance for files corruption (RAID 0) -> MORE than double the risk of catastrophic loss of data. Yes, correct, not a problem if there is a fresh backup.
    isn't education a better answer than blatant denial
    Again, obviously. For about seven years, we have been warning and warning constantly about the risks of RAID 0. The majority of RAID 0 users - at least based on the RAID problem threads we deal with here - appear to jump right into RAID without researching well. Frankly, some of us are just weary of cautioning and warning when most RAID wannabees (me, formerly) jump in anyway and then are crestfallen later when the array collapses. Sometimes the feeling (which I don't act upon) is to reply to one of the many broken RAID threads - "Tough tomatoes - you're screwed." Frankly, I'm tired of warning people about RAID who are convinced it will transform their computing experience. Yeah, I was in that camp once too. Yeah, I kept backups and used them for restoring way too often.
  • NiGHTSNiGHTS San Diego Icrontian
    edited Feb 2008
    MJancaitis wrote:
    All I'm saying is, isn't education a better answer than blatant denial? Just telling somebody "you don't need this" rather than explaining its risks and letting them decide what the heck they want to do?

    Typically, I'd agree with you. However, having issued said help to some, and watched others push help on deaf ears, I can agree completely with this rant. I'd say 85% of the time, that same person isn't willing to figure out what they need to do on their own. Even if given all links and pertinent information, they'll still come with hands outstretched, demanding help for something they really shouldn't be dealing with.

    I just recently attempted to explain to a guy that plays ultimately 1 game that a quad core processor on a $350 motherboard was going to give no benefit over a dual core + bloodiron. People are looking for e-peen bragging rights, more often than not, I feel. Unicorns won't fly out of your system when you use SLi on a 15'' LCD screen, sorry. No matter how right you may be, people just don't want to hear it.
  • kryystkryyst Ontario, Canada
    edited Feb 2008
    MJancaitis wrote:
    The key is actually knowing what you're doing. I, for instance, run a RAID 0 on a pair of Raptors, and keep a biweekly backup on a second drive. Am I so wrong, such a terrible person? I understand the risks, take efforts to protect against them, and felt like doing it all the same.

    All I'm saying is, isn't education a better answer than blatant denial? Just telling somebody "you don't need this" rather than explaining its risks and letting them decide what the heck they want to do?

    I agree absolutely which is why I pretty much said that don't do it unless you really know what your doing.

    That being said without turning things into a fight. I still submit that raid on a home system is 78% pointless. I agree that education is best. However do it smartly. Blindly jumping into Raid, like many people do is not the same as experimenting wtih linux. You'll get the raid up and going. Have a good run without known flaws even though your raid could be dying beneath you. Then suddenly blamo you've got nothing. Then you scour forums looking for a miracle cure to recover your data.

    That is why raid is a problem and that is why I wrote the rant.
  • SnarkasmSnarkasm 's-Hertogenbosch, The Netherlands Icrontian
    edited Feb 2008
    NiGHTS wrote:
    No matter how right you may be, people just don't want to hear it.

    If those people are towards whom this rant is directed, then isn't it essentially just a waste of time, then? ;)

    For people that want help and come to this forum and all they see is a bunch of high rollers saying they shouldn't even glance at RAID, it's a bit unfair, imo. That's all.
  • kryystkryyst Ontario, Canada
    edited Feb 2008
    MJancaitis wrote:
    If those people are towards whom this rant is directed, then isn't it essentially just a waste of time, then? ;)

    No because now I can just point them to this rant.
    For people that want help and come to this forum and all they see is a bunch of high rollers saying they shouldn't even glance at RAID, it's a bit unfair, imo. That's all.

    Fair enough. But for the high rollers there comes a time when we need to roll high. Look at any other situation - your car for example. You advance the timing 10degrees because of something you read on a forum once and keep running regular unleaded in it and in a month (if your lucky) suddenly your car is shot. Then you go to your mechanic or a forum and wonder what happened. I can guarantee your mechanic will shake your hand take your money and laugh his ass off behind the door.

    But it's systemic of a bigger problem. People to often leap without looking then cry foul after the fact. It's true my rant will likely fall on their deaf ears (or blind eyes I guess) but for anyone that may step on here first, or is already a fledgling member wondering about raid. Well this thread is a damn good starting point. If anything it'll at least (hopefully) put a couple caution flags up before they try raid.
  • LeonardoLeonardo Eagle River, Alaska Icrontian
    edited Feb 2008
    It's true my rant will likely fall on their deaf ears
    It will, and not because our members are stupid, but because there's so much hype about RAID. (Oh, this motherboard has RAID and it's only $20 more than the board without it! I hear you can double your files transfer speed by using RAID! Wow, I could pwn those slackers on Death Bunny 3 if I had RAID!)

    No not stupid, just over-eager, for lack of a better term.

    UPDATE: I am making this a sticky thread. Seeing that the anecdotal and informal advice that has been put out at least since 2002 at Icrontic/Short-Media/Icrontic has not caught many newer members' attention, maybe a permanent thread might.

    I invite experienced RAID users and or those with questions make good use of this thread.
  • edited Feb 2008
    Tex is going to **** the bed when he sees this.
  • ThraxThrax Professional Shill, Pokémaster, Watch Slut Austin, TX Icrontian
    edited Feb 2008
    Even if kryyst's OP may seem high-handed to some, the discussion it created was as sound as the initial advice. Kudos to you, Kryyst. Most people are not prepared for the imminent catastrophe of RAID.
  • QCHQCH Chicago Area - USA Icrontian
    edited Feb 2008
    I 100% agree with you, Kryyst. Almost every normal user can do without RAID. I run a dedicated RAID card. Three 300 GB drives in RAID 5 (with a hot swap ready) but that is for my server. I have a ton of home movies, pictures, all of my music, and DVDs. I want the redundancy of RAID 5 without having to do routine backups. The data isn't updated often enough.

    At work, however, I support high end work stations for CAD designers. These PCs are well over $10,000 each. 16 GB of RAM and one CAD file can be 8 GB or more. They need every bit of performance they can. They run RAID 0 on 4 10,000 RPM Serial SCSII (SAS Drives) with 4000 Mb clusters. For them, it works GREAT for performance. They are limited by bandwidth more often than drive speed.

    However, the OS is NOT on those drives and they know the risk of that setup. They've lost 3 drives over the past 2 years and lost days of work. But they think it's worth it.

    Normal Home users... !!!Just Say No to RAID!!!
  • kryystkryyst Ontario, Canada
    edited Feb 2008
    rapture wrote:
    Tex is going to **** the bed when he sees this.

    I don't think so. Tex knows exactly what the point of this is.
  • QCHQCH Chicago Area - USA Icrontian
    edited Feb 2008
    RAID... dont' do it but if you want to do it,do it right. Tex is all about doing it right. He knows the ins and outs of setting up a RAID array to maximize what a person needs...
  • HawkHawk Fl. Icrontian
    edited Feb 2008
    I read up on all the raid rage yrs ago and have still kept up with some of it even today, but decided it wasn't worth the trouble.
    Even though I had 5-6 pc's on my office network here at home.
    Especially seeing all the lost raid arrays and those searching for help to get them back.
    I went out and got myself three 10,000 rpm raptors for main HD's on the pc's I wanted to run faster.
    Then made sure I had plenty of ram.
    A good video card.
    Optimized my pc settings for aggressive running.
    Also optimizing broadband settings makes a difference too.
    I haven't lost a HD or any files for yrs.
    I doo backup my important files to other backup HD's on my network though.
    Just in case.
    You never know when a HD is going to take a nose dive and die on you.
    And I'm with you kryyst...
    Don't use it unless you have a good reason for using it.
    If you do use it. Learn the in/outs/recovery before setting it up & jumping into raid.
  • HarudathHarudath Great Britain Icrontian
    edited Feb 2008
    I have one 160GB SATA 5200rpm Hard Drive which I've had for almost 3 years. All I need.
  • mmonninmmonnin Centreville, VA
    edited Feb 2008
    I don't agree. I have a RAID 0 raptors. Its onboard RAID as well. I don't even make backups. Anyone who stores data/information on a raid drive is dumb in the first place. I could care less if I lose my RAID. Sure I have movies and crap on it, but its nothing I can't replace such as my OS and programs. Those are the things that are supposed to be on a RAID, the files that are accessed the most.

    I am sure that I've been on the better end of hard drives over the years as I've only had 1 hard drive go bad on me and it was under warranty. I've had other small ones I've scalvaged go bad on me, but those dont count. Those are like the 1-2gb drives of yesteryear....

    If a user can use hard drives to store just OS, programs and anything he doesn't care about losing then there is no reason to not have a RAID. Whats the risk? A few hours of downtime if and ONLY if a hard drive fails. The gain: better performance all the time.
  • mas0nmas0n dallas Icrontian
    edited Feb 2008
    Yeah I pretty much tell everyone to avoid RAID like the plague, but run 3 arrays on a dedicated controller in my main rig. 2x74GB RAID 0, 3x120GB RAID 5, 2x400GB RAID 0. Never had a problem, but if I ever did I'd know what to do.
  • KwitkoKwitko Sheriff of Banning (Retired) By the thing near the stuff Icrontian
    edited Feb 2008
    More drives = lower MTBF.
  • Nickboxer7Nickboxer7 KC,MO
    edited Mar 2008
    Kwitko wrote:
    More drives = lower MTBF.

    Not necessarily. Increasing the number of drives may lower their usage, but also installs the factor of having a higher chance of one drive failing, just do to manufacturer problems. When you buy a drive you know it could fail even if you use it correctly, and then you have to RMA. Try putting 5 of those together. That is a greater chance of a drive failing.

    I realize it goes both ways, but I wanted to bring the other side up.


    But I was wondering what you guys thought about 0+1 or 10 for a storage server? I was going to build one up and planned on doing striping for performance and mirroring for protection.
  • LeonardoLeonardo Eagle River, Alaska Icrontian
    edited Mar 2008
    Try putting 5 of those together. That is a greater chance of a drive failing.
    You have just described lower MTBF - less time (probable) before a drive fails.
  • Nickboxer7Nickboxer7 KC,MO
    edited Mar 2008
    Leonardo wrote:
    You have just described lower MTBF - less time (probable) before a drive fails.

    You are absolutely right. For some reason I mixed that up when I read it. I should just go to bed now. :(
  • kryystkryyst Ontario, Canada
    edited Mar 2008
    Nickboxer7 wrote:
    But I was wondering what you guys thought about 0+1 or 10 for a storage server? I was going to build one up and planned on doing striping for performance and mirroring for protection.

    Depends on what your requirements are for your storage server.
    1) How many people accessing it
    2) What type of data is on it (many small files, fewer large files) ie documents vs movies
    3) What sort of long term redundancy do you need.
    4) How much money do you want to spend

    In my position I would suggest if this is just a storage server for a typical house hold holding a variety of files but with only a few users on it and you don't really care either way about long term redundancy. Then I wouldn't bother with raid. However if I wanted a little bit of protection then I'd go with raid 5.

    If this is for a business, with say 20+ users accessing many smaller files frequently then I'd suggest doing a series of raid 1's. It gives you fantastic redundancy and high availability but you are paying for that by your storage costing you double (ie 2 100gb drives gives 100gb of data). Also in this fashion many smaller drives will provide a much greater benefit in speed then a few larger drives. But again cost goes up.

    Raid 1+0 I typically would reserve for things like SQL servers, media servers and Exchange Data stores where they are working with massive data files (.pst stores for example) and need high availability.
  • Nickboxer7Nickboxer7 KC,MO
    edited Mar 2008
    This is for a business where at any time there will be two to six people accessing files. The files are design files which range from very small to very large, depending on if they are basic or digital print type stuff. I really want something that will handle sharing the large files, but also have protection for them so that it is somewhat of a backup. Right now we run all the files from one design station which slows it down and then move them over once they are done to a USB drive (which is not very safe), and then back them up to CD's.

    What would you think about the NAS RAID devices vs. a server?
    kryyst wrote:
    Depends on what your requirements are for your storage server.
    1) How many people accessing it
    2) What type of data is on it (many small files, fewer large files) ie documents vs movies
    3) What sort of long term redundancy do you need.
    4) How much money do you want to spend

    In my position I would suggest if this is just a storage server for a typical house hold holding a variety of files but with only a few users on it and you don't really care either way about long term redundancy. Then I wouldn't bother with raid. However if I wanted a little bit of protection then I'd go with raid 5.

    If this is for a business, with say 20+ users accessing many smaller files frequently then I'd suggest doing a series of raid 1's. It gives you fantastic redundancy and high availability but you are paying for that by your storage costing you double (ie 2 100gb drives gives 100gb of data). Also in this fashion many smaller drives will provide a much greater benefit in speed then a few larger drives. But again cost goes up.

    Raid 1+0 I typically would reserve for things like SQL servers, media servers and Exchange Data stores where they are working with massive data files (.pst stores for example) and need high availability.
  • kryystkryyst Ontario, Canada
    edited Mar 2008
    NAS Raid devices are great. As long as you get a good one. I wouldn't recommend the Best Buy special for your type of needs. You don't need a SAN that would be overkill.

    You don't have a lot of users so high availability access won't be an issue. Raid 5 will do fine for you and give you and maximize your space. I would still have a secondary backup though.
  • Nickboxer7Nickboxer7 KC,MO
    edited Mar 2008
    kryyst wrote:
    NAS Raid devices are great. As long as you get a good one. I wouldn't recommend the Best Buy special for your type of needs. You don't need a SAN that would be overkill.

    You don't have a lot of users so high availability access won't be an issue. Raid 5 will do fine for you and give you and maximize your space. I would still have a secondary backup though.

    Yea, I'm still not sure the best method for backing something up like that. Should I get two of those built and then bring one in from home every week and copy everything new?
  • KwitkoKwitko Sheriff of Banning (Retired) By the thing near the stuff Icrontian
    edited Mar 2008
    Nickboxer7 wrote:
    But I was wondering what you guys thought about 0+1 or 10 for a storage server? I was going to build one up and planned on doing striping for performance and mirroring for protection.

    We use RAID 10 here at work for our SQL Server. I think it's the best balance between performance and security, especially if you're doing a lot of reads/writes. If your storage server is going to primarily serve files and not write so much, you're probably better off with RAID 5. Great redundancy and read speeds.
  • Mt_GoatMt_Goat Watching the mere mortals in chaos from high atop Mt. Olympus Icrontian
    edited Apr 2008
    Good thread kryyst. I have been preaching this for some time and also have been trying to explain why it doesn't work for home use and what is a better use of multiple drives for a performance home system for some time now.
    rapture wrote:
    Tex is going to **** the bed when he sees this.
    Tex is the one who made me see the light of how to get better perfomance from a home system with out using RAID 0. Tex knows that, as mentioned, hardware RAID over software RAID and dedicated controller cards over motherboard imbedded controllers is far superior for those who do need or wish to use it.

    The main thing with RAID 0 is that it is only good for the transfer of large files and not the small file loads and transfers used in everyday home useage including games! It also makes no sense to transfer a large file with a single RAID 0 from one location to another since the heads of anything but a good SCSI drive are simply not capable of the load. If someone wants to use a RAID 0 for say gaming where they load all the files to it from the install disc. that is all that RAID 0 array is going to really be good for, except maybe storing movie files that will need to be backed up on a separate drive. the file sizes involved in everyday useage, especially system operations is so small that tranfer speed does not really come into play by itself. This is where access times are much more critical. and NO RAID ARRAY WILL INCREASE THER ACCESS TIMES AS IT IS A MECHANICAL FUNCTION OF THE DRIVE ITSELF!

    A dedicated RAID controller card does 2 things that a motherboard embedded controller (all motherboard embedded controllers are software RAID) do not do. 1. They use their own processor dedicated to nothing but running that RAID array with no hit on main system performance since it isn't borrowing CPU power from the main system. 2. They all use their own memory to run the controller with no hit on main system memory. The onboard RAID solutions DO NOT have their own processor or memory. This is essentially what makes them all software as all they are composed of is a control chip, firmware and software to run them. I have seen an average hit on CPU performance and memory of 15% on the mobo software controllers. How could anyone think for a second that an additional 10 to 20 dollars for onboard RAID come close tom competing with a controller card that costs hundreds of dollars!!!

    This brings me to what I have learned first hand from Tex, who is our local master guru of drive system performance. I use the fastest access time hard drive I can find that is relatively small for nothing but the OS and anything associated with it. Then I use a separate HD for my programs and apps only. Finally I put all my storage on a separate HD and back that up regularly to an external HD. This drive system runs so smooth and access is great beacause the heads that run the HD are never trying to do 2 different tasks at the same time. It just runs like hot butter! :)
  • edited Aug 2008
    Redundacy, is the reason I chose to install a RAID (1) on my new system. I have had hard drives fail in the past and I didn't want to be bothered by another failure. Having a second hard drive with the exact copy of my primary hard drive without having to manually copy important files seemed like an ideal solution.

    Yes, I'm a novice (hence, Dummie)when it comes to RAID in's and out's but I don't think the problem has to do with RAID itself. Setting up a RAID on my system was quite easy. I think the problem with RAID is with the lack of explanation of problems you can encounter after you set up your RAID configuration. For example, I just updated my BIOS. After I updated my BIOS I could not boot into Windows using my RAID configuration but I could boot Windows using either hard drive separately. The reason for this was because after my BIOS update I started Windows without first telling my new BIOS that I was running a RAID set-up. Unfortunately, there are no warnings about this from any motherboard vendor and no where have I seen anyone talk about or explain what can happen to your RAID set-up after a BIOS update.

    I still think RAID (1) is a great solution but it just needs to be explained better to the not so informed.

    Cheers,
  • kryystkryyst Ontario, Canada
    edited Aug 2008
    The thing is that you could be getting better redundancy without using raid. Have your primary drive as normal then have it run scheduled backups to your second drive. Simple as that you then have full redundancy and easy portability should your system crash. Pull out the hdd with the backups on it and plop it into the new system and recover your backup.

    In your case the issue is that if your RAID fails, sure you can use the drives independently since it's RAID 1. But your know further ahead and you've just got the complication of having to deal with repairing the RAID should something go wrong, like it did in your case.

    Also keep in mind that RAID's are dumb. So if your data starts to get corrupted it'll mirror that corruption. Now doing a scheduled backup isn't immune to that but keep this in mind, most backup software will tell you if it had trouble backing up a file and create a report and if you are doing rotational backups, which you can usually have at least 2 since the backups are compressed you should have a good one. With RAID on the other hand if your system gets corrupted and goes BSOD then comes back with system32 style errors RAID won't save you and you'll have to do a full repair. A backed up system though means you won't loose any data and you can recover from your good backup.
  • foolkillerfoolkiller Ontario
    edited Feb 2009
    I think the title of this says it all. If you think a RAID array is the ultimate way to keep your data while being lazy, you're going to end up with an unpleasant surprise. I'm going to go into a bit of a story, as well as some details. I'll pop the story in first, because stories are fun, especially the horror kind.

    I've been running RAID arrays for a very long time. Back when I owned a Netfinity 5500 M20, I had two seperate arrays. A 6x18GB 10K RPM SCSI Raid 5 Array, and a 7x74GB Raid 5 Array. While I had lots of space, the antique drives I was running, weren't quite up to par, so I decided it was time to upgrade to a new server.

    First I bought myself a couple 3ware cards (by accident I ordered the wrong one TWICE for a customer, but oh well.)

    I tossed them in and got myself setup with a 4x500GB array in my new (to me) Dual Xeon 2.4 Ghz server. Everything worked like a champ. Eventually though, I started to need more space for all my junk. I ended up picking up 4 Seagate 1TB drives and this is where my horrors began.

    First off, I backed up all my data to one of the 1TB drives. Pulled the 500GB drives and setup a new array using 3 of the 1TB drives. After a day, I wondered what the hell was going on and heard the great clickety click of doom. After figuring out which drive it was, I pulled it, transferred the data off the extra disk to some old 250GB drives, and then rebuilt the array in a few hours using the 3 disks. Wow I thought, I have 2TB of data, that's awesome. So I proceeded to put all my data back on there, and everything was fine.

    Eventually I picked up another disk, and migrated the array to 3TB in size. The big thing I forgot to do, was add support in my kernel so that I could access and use >2TB drives. Needless to say, I had to do a reboot, and when the system came back up, my xfs filesystem went away, far far away. In my stupidity, I ran a chkdsk on it, obliterating most of my data in the process.

    After several hours of screwing around with my system, I eventually figured out there are TWO spots in the kernel that you need to enable >2TB disks at. I paid for this is music and video data, while having a spare backup of all my settings just by chance (LUCKY)

    This is a good description of why RAID isn't a backup solution, it doesn't take all that much to kill the filesystem on it. A good virus or ID ten T error will do it, as in my case.

    While there are a bunch of different raid levels, I'm going to touch on some of the basic ones

    RAID 0: Increases your transfer rates, IOs and capacity. The 0 stands for how many files you get back if something goes wrong.

    RAID 1: Increases your transfer rates on some controllers for reads, slightly slower writes, redundancy. Mostly run in pairs, if you lose a single drive, you won't lose all your data, however a bad sector might ruin your day still.

    RAID 2,3,4: Obsolete nuff said.

    RAID 5: Increases your transfer rates during reads, slow writes, redundancy for a single disk only. Must be run in 3 or more units. If one drive fails, you can rebuild. IF 2 FAIL, CRY. Alot of people don't realize that two failures in a RAID 5 array will mean the end of any data on it. Same applies as Raid 1 for bad sectors and such.

    RAID generally is not the best idea for home users. Too many people think it is magic and is going to give them 200MB/sec read speeds and such. There is always a tradeoff. Even with $400 RAID cards, I only see about 100MB/s reads, writes are much much slower. While I can load my games really fast, installing them takes twice as long as a single drive.

    Anyways, I've done enough storytelling and ranting. I can put it simply. If you think RAID is going to save all your data, eventually you are going to lose data. There is no substitute for backing up anything critical, period.

    Just my 2 cents.
  • LeonardoLeonardo Eagle River, Alaska Icrontian
    edited Feb 2009
    Thanks for taking the time for your input. There is actually a fairly large camp here at Icrontic of former RAID users, including me. In my opinion, at the desktop level, RAID is a bigger liability than benefit.

    People, if you want data security, back up or image to an EXTERNAL hard drive. Unplug the drive when not in use. If even greater security is needed, store the external drive at a location separate from your computer. This is much better backup security than any RAID setup. If you aren't serving large volumes of data on a continual basis, RAID is a toy. Nothing wrong with toys, as long as you understand the risks.
  • edited Dec 2009
    I've gotta say this place seems to get more "I have a raid problem" posts than anywhere else. Thanks for edumekating the interwebs.
  • photodudephotodude Salt Lake, Utah Member
    edited Dec 2009
    kryyst wrote:
    You want a speed boost take the money you are wasting on redundant drives, buy more ram, put in a better graphics card, don't bother with putting the drive in a raid just use it for backups. Whatever you do, there are much better ways to make a system better then spending it on a raid.

    I would add to that put the money that would have been wasted on redundant drives towards a quality SSD with ATA trim for a boot drive (move User folders, System Restore, Hibernate, and paging file to a mechanical drive; turn off readyboost, indexing, defragmentation, Write Caching, Superfetch for the SSD)

    SSD boot, more/faster RAM, and better/more Graphics cards will give better performance increases that Raid.

    Scheduled backups is a good alternative to Raid redundancy for the home use and NAS devices can be great for scheduling those backups
  • ardichokeardichoke Buttes Master B Lansing, MI Icrontian
    edited Dec 2009
    Pssh... I enjoy running a RAID in my home workstation. Then again, I actually understand how they work and have a separate, external, drive that I do backups to. That said, having a RAID 1+0 array is nice. Gives a marginal performance boost and I can lose 1 (or 2 depending on which 2) drives without having to reinstall and restore from backups. Most lusers however should stay the f*** away from RAID because they have no idea what they are doing.

    RAID != Backups
    RAID == SERIUS BUZINESS
  • lordbeanlordbean Ontario, Canada
    edited Dec 2009
    I likes me my RAID array as well, although I have lately begun to take data security into much larger account than I did previously. My setup at the moment is 4 drives in RAID5 with a hot spare.
  • ardichokeardichoke Buttes Master B Lansing, MI Icrontian
    edited Dec 2009
    Does your rig not support RAID6? Don't get me wrong, having a hot spare is nice... but if you're running RAID5 with a hot spare anyway you might as well have the extra parity already built and ready to go. Reduces the odds of having a 2nd failure while the array is rebuilding on the hot spare.
  • mertesnmertesn I am Bobby Miller Yukon, OK Icrontian
    edited Dec 2009
    ardichoke wrote:
    Does your rig not support RAID6? Don't get me wrong, having a hot spare is nice... but if you're running RAID5 with a hot spare anyway you might as well have the extra parity already built and ready to go. Reduces the odds of having a 2nd failure while the array is rebuilding on the hot spare.
    Most RAID controllers on motherboards don't support RAID6 - they stop at RAID5. You'll have to get an add-on board for RAID6.
  • photodudephotodude Salt Lake, Utah Member
    edited Dec 2009
    mertesn wrote:
    Most RAID controllers on motherboards don't support RAID6 - they stop at RAID5. You'll have to get an add-on board for RAID6.

    If your doing raid you should have an add-on board (as I recall ardichoke has an add-on board for his raid)
  • lordbeanlordbean Ontario, Canada
    edited Dec 2009
    It isn't strictly necessary with ICH RAID, although a controller would be more portable if I were to switch over to an AMD system. As I understand it, ICH RAID revisions are pretty much cross-compatible - ICH7 can read ICH10 RAID, and vice versa.
  • ardichokeardichoke Buttes Master B Lansing, MI Icrontian
    edited Dec 2009
    I actually don't have an add-on board for my desktop :-/ Then again, since I'm doing RAID1+0 instead of RAID5 I don't really see any performance hit from it.
  • mas0nmas0n dallas Icrontian
    edited Dec 2009
    Arrays that require parity is where the hardware controller really pays off, but being able to do cached read/writes is also awesome.
  • Ob-v8Ob-v8 SF Bay Area
    edited Jan 2010
    First off, I simply wanted to mirror my HDD, and have a real-time copy of C: and D: (traditional lettering scheme). I see RAID1 as an automated system for mirroring HDDs. I know what a true backup is, and I do use some DVDs in addition to the 4 drives (2 int. SATA for RAID1, 1 int.IDE for manual clones, 1 ext. and 1 off-site IDE for clone storage) where my files are going to reside when I get RAID to behave.

    Second, I don't think this should be rocket science, either hardware or software; if non-RAID HDD operations are robust to issues (from power to minor hardware failures), and don't require a degree in CS, then for Pete's sake so should RAIDed HDDs! Correct me if I'm wrong but aren't RAID1 controllers simply channel splitters, either in parallel or series? (WAG)

    Ah, nevermind that (blowing off steam), WTF is up with RAID metadata? Secret code, super-double secret area for storing the block... jeeminey christmas. Some people need to get over themselves and - JOIN THE TEAM. Standards people; put your shiz where everyone else does: in the boot sector! Where I could find it and delete it if need be had eh?

    I'm ticked-off about the metadata because of my experience with RAID1. I got a mobo w/onboard RAID. I thought it was hardware, but I am told the Silicon Image "SiI3114 SATARAID Controller" is but a 4-port SATA to PCL bridge... anyways, what I want to know is this: spinner says in his posts that one will not get an OS like XP to work from a software RAIDed HDD.

    Reason I want to know is I put my loaded OS disk into RAID1 (using the "copy data" command in the manual build routine) as the source disk, and now there is no bootable HDD. FWIW, Silicon Image's utility offers no data loss warning (I'm so used to those I thought clone to new HDD and voila!). The data is there; I can see it (read on).

    Now I salvaged my files by cloning the source to target myself (old Acronis bootable CD) so I could access them with a fresh install of XP on my int.IDE, but before I waste my time loading XP onto the now working RAID1 array I want to know if XP will work from within a software RAID1 array.

    Thanks for overlooking my pissin' and moanin', or being entertained by it.
  • kryystkryyst Ontario, Canada
    edited Jan 2010
    It will work if you can see the raid partition from the boot cd either directly because your mobo handles it correctly or through a secondary driver disk that can be loaded at the start of your windows installation (that Press F2 option right at the beginning).
  • photodudephotodude Salt Lake, Utah Member
    edited Jan 2010
    Ob-v8 wrote:
    First off, I simply wanted to mirror my HDD, and have a real-time copy of C: and D: (traditional lettering scheme). I see RAID1 as an automated system for mirroring HDDs.

    Correct me if I'm wrong but aren't RAID1 controllers simply channel splitters, either in parallel or series?

    WTF is up with RAID metadata? Where I could find it and delete it if need be had eh?

    I put my loaded OS disk into RAID1 (using the "copy data" command in the manual build routine) as the source disk, and now there is no bootable HDD.


    RAID1 does mirroring but not in the way your thinking. it's a 1:1 mirror It only mirrors a single drive within the array, every drive is the same in the array. Raid1 also has a performance hit due to the multiple simultaneous writes. note: mirroring is not cloning. if you get data corruption in raid 1 it will be on all drives in the array. Raid 1 is only for a mechanical failure safety net. and will always require two drives as a minimum.


    RAID1 controllers are not simply channel splitters, a channel splitter would take [data A] and split it into [data B] + [data C] which is also different then stripping that Raid 0 does.

    Raid doesn't work with the type of delete-able metadata that your thinking of any type of corruption to controller files can cause a systemic failure that will prevent reading of the data on the drives.

    Copying data from a boot drive to a RAID array via copy will not give you a boot drive, the same thing applies with copying data from Drive A to Drive B Drive B will not be boot-able. you have to use a program like ghost.
  • Ob-v8Ob-v8 SF Bay Area
    edited Jan 2010
    kryyst wrote:
    It will work if you can see the raid partition from the boot cd either directly because your mobo handles it correctly or through a secondary driver disk that can be loaded at the start of your windows installation (that Press F2 option right at the beginning).

    Thank you kryyst,

    so if I can load XP onto a RAID partition then I can boot XP from it. I'll give it a go.
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