drive error, next step?

[Jackal]

so here's dmesg output on CentOS5:

md: Autodetecting RAID arrays.
md: could not open unknown-block(8,17).
md: could not open unknown-block(8,18).
md: autorun ...
md: ... autorun DONE.
EXT3 FS on dm-2, internal journal

also have this earlier in dmesg.

SCSI device sda: drive cache: write back
sda: sda1
sda: p1 exceeds device capacity

PC seems REALLY slow, don't know why.

[Spankin Partier]

Did you have a RAID array set up in this computer? If so what was it, and what software are you using to run it (RAIDTools2 or MDADM). If you have a RAID config, post the results from this command:

cat /proc/mdstat

This will give the stat of your RAID devices.

[Jackal]

Hi Spankin,

It's BS software raid 0, two 74gig raptors, I think I screwed something up in the setup, as I have this:

mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/hda6 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
nfsd on /proc/fs/nfsd type nfsd (rw)

I used to just have /dev/md0 as I recall.


oh yeah and:

[root@thebeast ~]# cat /proc/mdstat
Personalities :
unused devices: <none>

[Spankin Partier]

So you are using your motherboard's 'fake' RAID then. If that's the case, reboot the computer and go into the motherboard's RAID BIOS (probably separate from the normal BOIS) and see if it has any diagnostics. It should tell you if everything is running alright or not. I'm sorta wondering if one of the drives are failing.

But if you're running RAID 0 then you should have lost everything if one of the drives did die. Could you possibly be running RAID 1, have a failing drive and the RAID is working extra hard trying to sort everything out?

[Jackal]

OMG, I think everything is messed up, just went into LVM manager, /dev/sdb is not even initialized!! I have 2 80gig WD JB's, and 2 74gig raptors (Nvidia Fake raid 0), my oh my wonder what I've done, I'll probably have to scrub linux and try again.....maybe I'll get it right, hate to lose my 500 emails in my inbox, LOL organization, NOT.

the drive sizes don't match up - logical volume is 214 gig? should only be 140ish. DOH!

[Spankin Partier]

For using RAID 0 that sounds about the right size. Only if you had both of the 80GB WD drives in a RAID 1 array and also both 74GB Raptor drives in a RAID 1 array should you end up with a total drive size 140 ish GB LVM drive.

I think you originally got RAID 1 and RAID 0 mixed up. RAID 1 is mirrored where one drive is a backup of the other, and RAID 0 is striped where files are spread across multiple drives for speed.

[Jackal]

I almost agree, I know the difference in Raid implementation, I don't, however, think I know how Linux implements it for "fake" raid.

my drives are like this

/dev/hda1-7
/dev/hdb1-2
/dev/sda
/dev/sdb

sda and sdb I wanted as 1 partition raid 0, so that should have been (74 X 2) gig. hda and hdb were to not be involved at all in the array, swap was to be on hdb2, and /boot was hda7

[Spankin Partier]

Is there any reason you'd like to do this using your motherboard's RAID system when Linux can do this for you?

If you are not running multiple OS's from within this box (Linux + Windows under VMware would count as one OS), then I'd use Linux's RAID. It's not very hard to add with Gentoo. Minor changes would be required to GRUB, 2 config files in your /etc directory (fstab, and mdadm.conf), and ensuring that your kernel has RAID support compiled into it.

With these automatic installers, I don't know how you'd specify how to install the OS as RAID 0. But I'm sure each distro has it's own WIKIs on this.

[Jackal]

Is there any reason you'd like to do this using your motherboard's RAID system when Linux can do this for you?

Yes, because I didn't/don't know how.

If you are not running multiple OS's from within this box (Linux + Windows under VMware would count as one OS), then I'd use Linux's RAID. It's not very hard to add with Gentoo. Minor changes would be required to GRUB, 2 config files in your /etc directory (fstab, and mdadm.conf), and ensuring that your kernel has RAID support compiled into it.

With these automatic installers, I don't know how you'd specify how to install the OS as RAID 0. But I'm sure each distro has it's own WIKIs on this.

This box is triple boot 2K Pro, XP Pro, and Cent 5 64Bit, winblows is on /dev/hda2 and 6 (XP is in a logical partition(I screwed that up ions ago)).

I do have VMware installed on the Cent partitions - but don't care if I lose it, won't be the 1st time, I've had to reinstall it, and it's respective o/s.

AND OBVIOUSLY I don't know how to break quotes out right either......

[Parn]

To create a Linux RAID0 on your 2 raptors:

fdisk /dev/sda
<press n to create a new partition sda1>
<choose fd as the partition id> (83 is standard linux partition and fd is linux software raid)
<press w to save the changes>
Do the same for /dev/sdb.

Now to create the array, type:
mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sda1 /dev/sdb1 --chunk=64

Once done, you can now do "mke2fs -j /dev/md0" to format md0 in ext3.

[Jackal]

To create a Linux RAID0 on your 2 raptors:

fdisk /dev/sda
<press n to create a new partition sda1>
<choose fd as the partition id> (83 is standard linux partition and fd is linux software raid)
<press w to save the changes>
Do the same for /dev/sdb.

Now to create the array, type:
mdadm --create /dev/md0 --level=0 --raid-devices=2 /dev/sda1 /dev/sdb1 --chunk=64

Once done, you can now do "mke2fs -j /dev/md0" to format md0 in ext3.

Can any of this be done, w/out a reinstall, considering the mess my drives are in right now?

[Spankin Partier]

^^^^ That's pretty much the majority of the work required to set up a RAID 0 partition. TAfter that would be the actual installation of the OS and then the configuring of it to allow it to boot properly.

But before we can consider this, will you be needing to share any information on this partition with the other operating systems? Hopefully not. OS level RAID makes sharing information on RAID partitions with other resident OSs difficult.

Here's a PDF I found that explains how to install RHEL (CentOS) with RAID using the graphical installer.

http://download.boulder.ibm.com/ibmd...D-Tutorial.pdf

I'm sure there's many other usefull links out there.

[Jackal]

hmmm, reinstall, :sigh:, i would have liked to split the array - 74 gig for Linux, and 74 on another partition for XP - but if it's too much hassle, it's not necessary.

[Spankin Partier]

That would then have to be done either at the hardware level or have each OS do it for thier own partition. But seeing as you're not running a server version of Windows, you're stuck doing it at a 'hardware' level.