Poll: Do you use RAID?

Be advised that this is a public poll: other users can see the choice(s) you selected.

+ Post New Thread
Page 1 of 2 12 LastLast
Results 1 to 15 of 16
Windows Thread, Do you use RAID - if so, what type? in Technical; Got an opportunity to redo our hard drives so I thought I might go for RAID. Only software, I'm afraid, ...
  1. #1
    eean's Avatar
    Join Date
    May 2006
    Location
    Seoul
    Posts
    571
    Thank Post
    70
    Thanked 56 Times in 40 Posts
    Rep Power
    31

    Do you use RAID - if so, what type?

    Got an opportunity to redo our hard drives so I thought I might go for RAID. Only software, I'm afraid, but apparently that's still better than no-RAID. So, do you have RAID 0 (mirror),1 (striped) or 5 (striped with parity)?
    Having done some research on the webnet, some places say you'd be a complete fool to use RAID 1 for anything other than swap files etc... But, with a good backup strategy it should be fine?? We're talking about staff and pupil data here and running some software, plus software distribution.
    Other places say the CPU load, and delay in writing (especially small files) is really high with RAID 5. Is none of this offset by the fact you are sharing the write between 3 drives?

    Or will I not even notice the difference and not bother with RAID at all? Do other factors (such as network interface) become the weaker link? 1 Server doing all jobs (print, wsus, file, domain etc..) 700mb, 1.5ghz. 50 computers. Primary school. Some software run from the server. Currently 100mbs network card but might upgrade this to gigabit if I get round to it. (Have gigabit port on the switch).

    Thanks!

  2. #2

    webman's Avatar
    Join Date
    Nov 2005
    Location
    North East England
    Posts
    8,414
    Thank Post
    642
    Thanked 964 Times in 664 Posts
    Blog Entries
    2
    Rep Power
    327

    Re: Do you use RAID - if so, what type?

    Hardware RAID5+ on one MIS server and software RAID1 on our web server.

    Software is always slower than hardware, especially with RAID5 as it has to write to all disks in the array every time.

  3. #3
    Busybub's Avatar
    Join Date
    Feb 2007
    Posts
    384
    Thank Post
    44
    Thanked 39 Times in 37 Posts
    Rep Power
    22

    Re: Do you use RAID - if so, what type?

    We use RAID5 and RAID1 on different servers. Try to use 5 if the hardware allows, but some of our stuff only does RAID1.

    Tried software once but the speed difference is noticably slower. Wouldn't bother again considering you can get a decent PCI based RAID5/1 card for 45 quid, or a cheap RAID1 only for less than a tenner.

  4. #4
    timbo343's Avatar
    Join Date
    Dec 2005
    Location
    Leeds/York area, North Yorkshire
    Posts
    3,100
    Thank Post
    314
    Thanked 296 Times in 206 Posts
    Rep Power
    122

    Re: Do you use RAID - if so, what type?

    We use Raid 5 on the 2 file servers with a few drives mirrored (Raid 1) and then on some other servers (raid 0). It depends on the importance of the server and what it does. To be honest, Raid can be a bitch when it dies or the server goes down

  5. #5

    Norphy's Avatar
    Join Date
    Jan 2006
    Location
    Harpenden
    Posts
    2,502
    Thank Post
    57
    Thanked 349 Times in 269 Posts
    Blog Entries
    6
    Rep Power
    129

    Re: Do you use RAID - if so, what type?

    All of our servers have mirrored boot drives, some with hardware RAID controllers, other with software. The file servers, SQL servers and email servers have RAID 5 for their data volumes. We did have a RAID controller which did RAID 3 at one point but it was pants.

  6. #6

    maniac's Avatar
    Join Date
    Feb 2007
    Location
    Kent
    Posts
    3,071
    Thank Post
    210
    Thanked 430 Times in 310 Posts
    Rep Power
    144

    Re: Do you use RAID - if so, what type?

    All our servers also have RAID 1 (mirrored) boot volumes, and if they have local data storage, this runs RAID5 or RAID1 as well depending on the number of drives.

    Our storage server (which has an array of 9 250GB SATA drives) runs RAID 6+1 which is an extension to RAID 5 and also gives us a spare 'hot' drive incase one fails. This spare drive jumps straight in and the array is re built straight away in the event of a drive failure. In theory 2 drives could fail at once on our storage array and we'd be ok.

    Reason we went for this is this storage array stores ALL our data for the entire network, (excluding exchange and SQL which are both stored on their local servers.) so it's critial it doesn't fail, and given this schools history of data going missing, we wern't taking any chances!

    I can't even imagine managing a server now that doesn't use RAID, as the thing with hard drives is it's not if it fails, it's when! On average we have to replace one drive every 3 or 4 months (we do have a lot of drives in our servers thou) Imagine if we didn't have RAID, all that downtime and resotring from backups, makes me shudder to think about it!

    Mike.

  7. #7


    Join Date
    Jan 2006
    Posts
    8,202
    Thank Post
    442
    Thanked 1,032 Times in 812 Posts
    Rep Power
    339

    Re: Do you use RAID - if so, what type?

    Tried software once but the speed difference is noticably slower. Wouldn't bother again considering you can get a decent PCI based RAID5/1 card for 45 quid, or a cheap RAID1 only for less than a tenner.
    These cheap RAID cards are technically software RAID, they are also known as fake raid. True hardware RAID is where the OS driver is unaware of the underlying disk and the OS driver only sees RAID arrays. In fake RAID the OS and the BIOS in the card provide software RAID. Linux software RAID is actually faster than fake RAID and as a result nobody bothers writing Linux drivers for these cards.

  8. #8

    Join Date
    Jul 2006
    Location
    London
    Posts
    2,962
    Thank Post
    160
    Thanked 152 Times in 116 Posts
    Rep Power
    49

    Re: Do you use RAID - if so, what type?

    5 out our 6 main servers have hardware RAID 5
    The other main one is the ISA server so didnt really need it, thats software mirrored

  9. #9
    ajbritton's Avatar
    Join Date
    Jul 2005
    Location
    Wandsworth
    Posts
    1,632
    Thank Post
    23
    Thanked 75 Times in 45 Posts
    Rep Power
    34

    Re: Do you use RAID - if so, what type?

    RAID 5 is a bit pointless now that hard drives are so inexpensive. I believe RAID 10 (or 0+1) is the way to go. This is a combination of mirroring (to give resiliency) and striping (for performance).

    RAID 5 suffers from what is known as the RAID 5 write penalty. Every time data is written to the array, all the disks must read some data so that the parity can be calculated. It's therefore essential to have write caching on servers which have high data write rates. This is a risk as if anything dies, the write cache will evaporate and corrupt the array. This means a battery backed cache is essential.

    EDIT: Also, avoid software RAID at all costs!

  10. #10

    bossman's Avatar
    Join Date
    Nov 2005
    Location
    England
    Posts
    3,967
    Thank Post
    1,212
    Thanked 1,075 Times in 766 Posts
    Rep Power
    332

    Re: Do you use RAID - if so, what type?

    ajbritton:

    I have to disagree with you on this one as i have had good experience of hardware raid 5 which really saved my bacon when one of the drives went caput i didn't even notice it as the raid was reconfigured from the parity information from the other drives automatically which rebuilt the redundant drive and never missed a beat. This was on our MIS server too.

    Have a quick read of the tutorials below i feel you may have been mis-informed

    http://www.acnc.com/04_00.html

    P.S agree with you totally on software raid.

  11. #11


    Join Date
    Jan 2006
    Posts
    8,202
    Thank Post
    442
    Thanked 1,032 Times in 812 Posts
    Rep Power
    339

    Re: Do you use RAID - if so, what type?

    Actually the software RAID = bad argument isn't always the case, there are many situations where software raid is preferred. Software raid is more flexible, (does your hardware raid controller email you if a disk fails?). It is certainly cheaper compared to 'real' RAID cards and software RAID can actually be faster than hardware RAID (as it's dependant upon processor speed rather than hardware controller), there is a detailed list of pros vs cons here. Of course this applies to linux raid, windows software raid does suck.

  12. #12
    DMcCoy's Avatar
    Join Date
    Oct 2005
    Location
    Isle of Wight
    Posts
    3,487
    Thank Post
    10
    Thanked 502 Times in 442 Posts
    Rep Power
    114

    Re: Do you use RAID - if so, what type?

    I use Raid 1+0, 1, 0+1 and 5. I also don't like software RAID, and even took a 50% space cut over using it on the Mac servers with the xraid!

  13. #13
    ajbritton's Avatar
    Join Date
    Jul 2005
    Location
    Wandsworth
    Posts
    1,632
    Thank Post
    23
    Thanked 75 Times in 45 Posts
    Rep Power
    34

    Re: Do you use RAID - if so, what type?

    @bossman: I'm not saying RAID 5 does not work, but I stand by what I said. RAID 10 or (0+1) will give better performance than RAID 5. The site for which you posted a link says that RAID 10 and 0+1 given better I/O rates than RAID5.

    RAID 5 only gives moderate write performance. If a disk fails, performance will be rubbish (until drive is replaced or hot swap spare comes fully online) as the controller needs to reconstruct the missing data from the parity information striped across the remaining drives.

    RAID 10/0+1 gives excellent write performance (because the data is striped) and does not degrade if a disk fails (because the data is mirrored).

    I would concede that ultimate write performance is probably not an issue for school file servers (although if you are trying to get the best out of SIMS, every little bit probably helps), but I think the reliability aspect does it for me.

  14. #14
    eean's Avatar
    Join Date
    May 2006
    Location
    Seoul
    Posts
    571
    Thank Post
    70
    Thanked 56 Times in 40 Posts
    Rep Power
    31

    Re: Do you use RAID - if so, what type?

    Well... It doesn't matter now! I put my spare hard drive in an it went 'Click... Click... Click'. Hmm... not a good start - RAID or no RAID. This drive was sent to me last year, 4 days after I needed it as part of the RM Next Day Onsite service agreement. Well that was a couple of hundred quid well spent!

  15. #15

    localzuk's Avatar
    Join Date
    Dec 2006
    Location
    Minehead
    Posts
    18,164
    Thank Post
    522
    Thanked 2,555 Times in 1,983 Posts
    Blog Entries
    24
    Rep Power
    879

    Re: Do you use RAID - if so, what type?

    I'm likely in the same boat as everyone else. Generally, our servers have RAID 1 for the boot volume and RAID 5 for the actual storage, but this varies (depending on how many disks are in the server...).



SHARE:
+ Post New Thread
Page 1 of 2 12 LastLast

Similar Threads

  1. Appliance type machines
    By plexer in forum Hardware
    Replies: 14
    Last Post: 9th August 2007, 07:06 PM
  2. I-Desk Type of Desks
    By Grommit in forum Hardware
    Replies: 4
    Last Post: 29th June 2007, 01:34 PM
  3. VLE-type program (Sam Learning) IE based - suggestions?
    By gwendes in forum Educational Software
    Replies: 10
    Last Post: 5th January 2007, 12:19 PM
  4. Network type
    By HodgeHi in forum Wireless Networks
    Replies: 7
    Last Post: 3rd August 2006, 05:38 PM
  5. Good NAS type distro ?
    By Pear in forum *nix
    Replies: 5
    Last Post: 15th May 2006, 10:21 AM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •