Trashed Raid 5 software array

DISCUSSION Mark Thompson 2 participants 2 messages Nov 7, 2004 MD RAID

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Mark Thompson

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2004-11-07 02:50 UTC #0 lore raw

Hi there,

I've search low and high and havn't been able to find a solution for my problem with a software raid that I have setup under linux.

Kernel: 2.6.6
Controller: PDC202XX (Promise TX2 ATA100 IDE Controller)

Up until recently everything was fine, but recently the array has started playing up and dropping a disk and when I reboot the disk doesn't have the superblock for the md device and as a result can't start, I then explored the disk using cfdisk and the disk had no partition there. So I reformated and this is what I get from mdadm now:

* When I try to assemble the array manually:

cold:~# mdadm -Af /dev/md1 /dev/hd[fjl]1
mdadm: no RAID superblock on /dev/hdj1
mdadm: /dev/hdj1 has no superblock - assembly aborted

* When I assemble the array with the two disks I know work:

cold:~# mdadm -A /dev/md1 /dev/hd[fl]1
mdadm: failed to RUN_ARRAY /dev/md1: Invalid argument

* And mdadm -D

cold:~# mdadm -D /dev/md1
/dev/md1:
        Version : 00.90.01
  Creation Time : Tue May 25 14:19:54 2004
     Raid Level : raid5
    Device Size : 117218176 (111.79 GiB 120.03 GB)
   Raid Devices : 3
  Total Devices : 2
Preferred Minor : 1
    Persistence : Superblock is persistent

Update Time : Tue Nov 2 09:18:08 2004
State : dirty, degraded
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 32K

UUID : 1acc6a85:ce7440d9:dfa74489:64bd5694
Events : 0.343086

Number Major Minor RaidDevice State
0 0 0 - removed
1 57 65 1 active sync /dev/hdl1
2 33 65 2 active sync /dev/hdf1

It is usually a raid 5 array with 3 x 120 gig disks on it.

Guy

2004-11-07 03:07 UTC #1 lore raw

Based on the output of mdadm -D /dev/md1... It looks like your array is working just fine, but missing 1 disk. You should have access to your data now, without any extra effort.

Since your array is running and working just fine (I hope). Just add the missing disk with this command.
mdadm /dev/md1 -a /dev/hdj1

You may want to test the disk first with this command. dd if=/dev/hdj of=/dev/null bs=1024k
Note: I said test the disk, not the partition.

Any questions? Email back before you do anything that may risk your data.

Guy

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Mark Thompson
Sent: Saturday, November 06, 2004 9:50 PM
To: Linux Raid
Subject: Trashed Raid 5 software array