On Thu, 27 May 1999, James O'Kane wrote:
Hi,
> I setup a raid 5 with 5 18G disks. 3 for data, 1 for parity and one hot
> swap. This config file I used is:
What? go read
http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/Software-RAID.HOWTO.html.
Using raid without really undesrtanding what is, and how it works, could
give you a false sense of security, which is the worst.
Raid 5 doesn't have parity disk (raid 4 does). It spreads parity amongst
all the disks.
> raiddev /dev/md0
> raid-level 5
> nr-raid-disks 4
> nr-spare-disks 1
> chunk-size 128
> parity-algorithm left-symmetric
>
>
> device /dev/sdc1
> raid-disk 0
> device /dev/sdd1
> raid-disk 1
> device /dev/sde1
> raid-disk 2
> device /dev/sdf1
> raid-disk 3
> device /dev/sdg1
> spare-disk 4
It seems to me that this config file is wrong. Again, go read the
Software-RAID-Howto by Jakob. (clue: spare-disk 4).
> I made the raid, put an ext2 file system on it, and copied about 9gigs of
> data to it, then rebooted. After rebooting, we got errors like this:
>
> Data overrun detected in Data-In phase, tag 13;
> and
> Have seend Data Phase. Length=122880 NumSGs=30
> and a few errors with SEQADDR and SAVED_TCL in them.
I guess this is surely due to disks/controller (won't you be using
IBM disks?) but certainly, you had luck in being able to build a raid with
that config. Guess that the spare-disk wrong option went unadverted to the
*picky* raid config file parser...
Also, which kernel version/raid patch version are you using?
> First question I guess would be, is this a problem with the raid?
> If it is, is there a know fix? We were hoping to use a software raid, but
> a hardware raid is looking better and better. Does anyone have a
> recommendation on a raid controller card?
I guess the option of actually *knowing* what raid *is* looks
better. After that, you'd be able to easily decide which (sw/hw) one to
use.
sw raid is better/worst because you can control almost every parameter,
which isn't available on all hw controllers. But it also requires you to
know exactly what you're doing.
I can swear once you got a right sw raid working you won't be
dissapointed, especially on SMP machines...
Anyway, I'd bet is a hardware/hardware support related problem.
Which brand/model of controller/disks are you using?
greetings,
*****---(*)---**********************************************---------->
Francisco J. Montilla Systems & Network administrator
[EMAIL PROTECTED] irc: pukka Seville Spain
INSFLUG (LiNUX) Coordinator. www.insflug.org - ftp.insflug.org
