software RAID-1 data recovery
Posted by markmh on 2012/1/30 0:31:14
Hello,
We have a software RAID 1 array, and a few hundred gigs of data have disappeared. The type is a software not a hardware RAID. I believe that we have both sda and sdb disks that should be mirroring each other. Error message in /var/log/messages (below) indicates a problem with sda.
Our priority is to recover the data. It contains the research of a few people. What is a good way to access the data safely?
We would like to be able to copy it to an external disk. What is the best (safe) way to try to look at the contents of the each of the two disks, sda and sdb, separately? I am afraid to try anything in case I make things worse.
I saw these commands suggested somewhere, but I am not sure if these apply in my situation:
umount /compute
mkdir /compute-other
mount /dev/sdb /compute
mount /dev/sda /compute-other
Any help would be appreciated. Thanks.
(more info, FYI, if useful:
system info: CentOS release 4.4 (final) operating system
distribution is Rocks release 4.2.1 (Cydonia)
/proc/mdstat gives:
Personalities :
unused devices:
/etc/fstab gives:
[Moderator edit: Added code tags to preserve formatting.]
/var/log/messages gives this, and repeats:
Jan 22 04:09:20 compute-1-22.local ntpdate[28121]: cap_set_proc failed.
Jan 22 04:09:21 compute-1-22.local ntpd[28125]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:20:50 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Currently unreadable (pending) sectors
Jan 22 04:20:50 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Offline uncorrectable sectors
Jan 22 04:27:40 compute-1-17.local ntpdate[16403]: cap_set_proc failed.
Jan 22 04:27:41 compute-1-17.local ntpd[16407]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:37:07 compute-1-20.local ntpdate[25104]: cap_set_proc failed.
Jan 22 04:37:07 compute-1-20.local ntpd[25108]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:44:03 compute-1-19.local ntpdate[17662]: cap_set_proc failed.
Jan 22 04:44:03 compute-1-19.local ntpd[17666]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:44:23 compute-1-24.local ntpdate[17321]: cap_set_proc failed.
Jan 22 04:44:23 compute-1-24.local ntpd[17325]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:50:49 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Currently unreadable (pending) sectors
Jan 22 04:50:49 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Offline uncorrectable sectors
Jan 22 04:54:13 compute-1-16.local ntpdate[8123]: cap_set_proc failed.
Jan 22 04:54:13 compute-1-16.local ntpd[8127]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 05:00:12 compute-1-21.local ntpdate[23242]: cap_set_proc failed.
Jan 22 05:00:12 compute-1-21.local ntpd[23246]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 05:01:04 compute-1-7.local ntpdate[8102]: no server suitable for synchronization found
Jan 22 05:01:04 compute-1-12.local ntpdate[11055]: no server suitable for synchronization found
Jan 22 05:01:04 compute-1-14.local ntpdate[17838]: no server suitable for synchronization found
Jan 22 05:01:05 compute-1-25.local ntpdate[12129]: no server suitable for synchronization found
Jan 22 05:01:05 compute-1-9.local ntpdate[27772]: no server suitable for synchronization found
Jan 22 05:01:07 compute-1-15.local ntpdate[16657]: no server suitable for synchronization found
Jan 22 05:01:07 compute-1-6.local ntpdate[13937]: no server suitable for synchronization found
)
We have a software RAID 1 array, and a few hundred gigs of data have disappeared. The type is a software not a hardware RAID. I believe that we have both sda and sdb disks that should be mirroring each other. Error message in /var/log/messages (below) indicates a problem with sda.
Our priority is to recover the data. It contains the research of a few people. What is a good way to access the data safely?
We would like to be able to copy it to an external disk. What is the best (safe) way to try to look at the contents of the each of the two disks, sda and sdb, separately? I am afraid to try anything in case I make things worse.
I saw these commands suggested somewhere, but I am not sure if these apply in my situation:
umount /compute
mkdir /compute-other
mount /dev/sdb /compute
mount /dev/sda /compute-other
Any help would be appreciated. Thanks.
(more info, FYI, if useful:
system info: CentOS release 4.4 (final) operating system
distribution is Rocks release 4.2.1 (Cydonia)
/proc/mdstat gives:
Personalities :
unused devices:
/etc/fstab gives:
# This file is edited by fstab-sync - see 'man fstab-sync' for details
LABEL=/ / ext3 defaults 1 1
none /dev/pts devpts gid=5,mode=620 0 0
none /dev/shm tmpfs noexec,nosuid 0 0
none /proc proc defaults 0 0
LABEL=/state/partition /state/partition1 ext3 nosuid,defaults 1 2
none /sys sysfs defaults 0 0
LABEL=/var /var ext3 defaults 1 2
/dev/sda3 swap swap defaults 0 0
192.168.1.250:/export/home /home nfs nosuid,intr,rsize=32768,wsize=32768,noatime 0 0
192.168.1.250:/compute /compute nfs rsize=32768,wsize=32768,noatime,nosuid,nodev,intr 0 0
/dev/hdc /media/cdrom auto pamconsole,exec,noauto,managed 0 0
/dev/fd0 /media/floppy auto pamconsole,exec,noauto,managed 0 0
[Moderator edit: Added code tags to preserve formatting.]
/var/log/messages gives this, and repeats:
Jan 22 04:09:20 compute-1-22.local ntpdate[28121]: cap_set_proc failed.
Jan 22 04:09:21 compute-1-22.local ntpd[28125]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:20:50 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Currently unreadable (pending) sectors
Jan 22 04:20:50 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Offline uncorrectable sectors
Jan 22 04:27:40 compute-1-17.local ntpdate[16403]: cap_set_proc failed.
Jan 22 04:27:41 compute-1-17.local ntpd[16407]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:37:07 compute-1-20.local ntpdate[25104]: cap_set_proc failed.
Jan 22 04:37:07 compute-1-20.local ntpd[25108]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:44:03 compute-1-19.local ntpdate[17662]: cap_set_proc failed.
Jan 22 04:44:03 compute-1-19.local ntpd[17666]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:44:23 compute-1-24.local ntpdate[17321]: cap_set_proc failed.
Jan 22 04:44:23 compute-1-24.local ntpd[17325]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 04:50:49 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Currently unreadable (pending) sectors
Jan 22 04:50:49 compute-1-11.local smartd[3642]: Device: /dev/sda, 1 Offline uncorrectable sectors
Jan 22 04:54:13 compute-1-16.local ntpdate[8123]: cap_set_proc failed.
Jan 22 04:54:13 compute-1-16.local ntpd[8127]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 05:00:12 compute-1-21.local ntpdate[23242]: cap_set_proc failed.
Jan 22 05:00:12 compute-1-21.local ntpd[23246]: cap_set_proc() failed to drop root privileges: Operation not permitted
Jan 22 05:01:04 compute-1-7.local ntpdate[8102]: no server suitable for synchronization found
Jan 22 05:01:04 compute-1-12.local ntpdate[11055]: no server suitable for synchronization found
Jan 22 05:01:04 compute-1-14.local ntpdate[17838]: no server suitable for synchronization found
Jan 22 05:01:05 compute-1-25.local ntpdate[12129]: no server suitable for synchronization found
Jan 22 05:01:05 compute-1-9.local ntpdate[27772]: no server suitable for synchronization found
Jan 22 05:01:07 compute-1-15.local ntpdate[16657]: no server suitable for synchronization found
Jan 22 05:01:07 compute-1-6.local ntpdate[13937]: no server suitable for synchronization found
)
This Post was from: https://www.centos.org/newbb/viewtopic.php?forum=27&topic_id=35538&post_id=153446