Hello Everyone,
First time CentOS poster :) I have CentOS 4 installed on the head node of a
Sun Gridengine cluster set up in a RAID. The head node has four hard
drives, and I assume that drives 1 and 2 are in a raid and then drives 3 and
4 are in another raid. I was trying to expand the OS partition on drive 1
because it was full. I took drive 1 out, put it in my Fedora 8 box as a
secondary drive, booted up into Fedora, and saw it had the partition
structure:
/ 8GB
/var 4GB
/swap 1GB
and an "unknown" partition 101.4GB
I did a cp -rfa on the / and /var files for a backup (I know, not the best
way). Restarted my Fedora into Windows to take a look at it using Paragon
Partition Manger. Restarted into Fedora and using gparted, formatted the
"unknown" partition as ext3 - I think that is where I made my fatal
mistake
- and moved the /swap to the middle of the drive, moved the /var to the
middle and expanded to 10GB, and then expanded / to about 50GB to fill up
the rest.
I had also took drive 2 out of the head node and into my Fedora, and saw it
had the partition structure:
/swap 15GB
and an "unknown" partition 101.4GB
Ok, now when I put everything back into the head node, and reboot, the BIOS
sees all four drives, and from what I can tell, recognizes the first raid
(of drives 3 and 4), but says it can only find one disk for the second raid
(drives 1 and 2). I can't find any way around this.
Looking at my /etc/raidtab file:
raiddev /dev/md0
raid-level 1
nr-raid-disks 2
nr-spare-disks 0
persistent-superblock 1
device /dev/sdc1
raid-disk 0
device /dev/sdd1
raid-disk 1
raiddev /dev/md1
raid-level 0
nr-raid-disks 2
persistent-superblock 1
chunk-size 4
device /dev/sda4
raid-disk 0
device /dev/sdb2
raid-disk 1
It says it can bring up md0 ok, but not md1. Right now, I am going to try
to restore the "unknown" partition that I deleted from drive 1 using
the
"unknown" partition from drive 2.
Any ideas on how to get myself out of this mess? I feel like I really
messed it up good. This is a server for our work, and we have a couple
years worth of data on it, so I would really like to fix it rather than
reinstall.
Thank you greatly for any help!
Jeff Sadino
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Jeff Sadino wrote:> Hello Everyone, > > First time CentOS poster :) I have CentOS 4 installed on the head > node of a Sun Gridengine cluster set up in a RAID. The head node has > four hard drives, and I assume that drives 1 and 2 are in a raid and > then drives 3 and 4 are in another raid. I was trying to expand the > OS partition on drive 1 because it was full. I took drive 1 out, put > it in my Fedora 8 box as a secondary drive, booted up into Fedora, and > saw it had the partition structure: > / 8GB > /var 4GB > /swap 1GB > and an "unknown" partition 101.4GB... probably LVM. wow, you made a nice mess.
> raiddev /dev/md1 > raid-level 0 > nr-raid-disks 2 > persistent-superblock 1 > chunk-size 4 > device /dev/sda4 > raid-disk 0 > device /dev/sdb2 > raid-disk 1 > > It says it can bring up md0 ok, but not md1. Right now, I am going to > try to restore the "unknown" partition that I deleted from drive 1 using > the "unknown" partition from drive 2. > > Any ideas on how to get myself out of this mess? I feel like I really > messed it up good. This is a server for our work, and we have a couple > years worth of data on it, so I would really like to fix it rather than > reinstall.Sorry, recovery is impossible at this point. md1 is a raid0 device. Since you have toasted one member partition, the whole thing it toast. I recommend clubbing whoever set it up in the first place with a clueby4 and then yourself.
I have access to all of the HEX data on each drive, and I now which sector each stripe starts at. Is there any way that I can reconstruct my data from that? When a file gets split up in RAID0, does the controller use the same sectors on each stripe to write the file parts? Thanks, Jeff On Wed, Mar 3, 2010 at 9:39 PM, Sorin Srbu <sorin.srbu at orgfarm.uu.se> wrote:> >-----Original Message----- > >From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On > Behalf > >Of Timo Schoeler > >Sent: Thursday, March 04, 2010 8:15 AM > >To: CentOS mailing list > >Subject: Re: [CentOS] Recover RAID > > > >>> Backups? I wish :) I will now. > >>[...] > >> Eh? Raid0 with no backups? For real? > > > >Backups are for sissies; running a hara-kiri RAID demands *not* having > >backups. Or did the kamikaze pilots have parachutes? > > 8-) > > Or as Linus Torvalds is said to have said; "Real men don't use backups, > they > post their stuff on a public ftp server and let the rest of the world make > copies." > > ;-) > -- > /Sorin > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20100305/6e5d59a2/attachment-0002.html>
Jeff Sadino wrote:> I have access to all of the HEX data on each drive, and I now which > sector each stripe starts at. Is there any way that I can reconstruct > my data from that? When a file gets split up in RAID0, does the > controller use the same sectors on each stripe to write the file parts?if a raid0 has a stripe size of 32k, then every other 32k is written on one drive, and every other 32k is written on the next drive. if you lose one drive, then every other 32k of your file system is wiped out, gone, kaput. its like taking a 12-gauge shotgun to your data and directory information.