Topic: Best method of repair- RAID

[ber]

Hi, I migrated my system onto new hardware. The old system was 7.5 running two IDE PATA 80GB Drives in RAID1. Motherboard was starting to cause intermittant performance issue- capacitors starting to "bulge" 

So I got a new Box- similar setup but the Drives were SATA drives (80GB). I installed SME onto the new hardware- ran the updates and then restored from the backup using default backup software.
Everything went well until I found that I could not VPN into the server- I had the same problem a few years ago and found out that the issue was a incorrectly setup RAID. After weeks of trying to resolve it I got someone in to try and fix it for me, just got cold feet rather than break my server (too much at stake)- he is no longer available. After a few more years of maintaining the system i'm now a little more confident to maybe try and resolve it myself.
Ive gone through the docs (RAID manual rebuild) and have an idea what the issue is but would like to some input from the community to confirm that I see what i need to see and what is the correct way to resolve the problem.

From the output its clear the the second disk is not part of the RAID setup and the RAID setup is well "weird"?? A RAID array on one disk with two partitions??
- correct to say that sdb is not being used.
- sdc is my USB backup disk.

[root@server ~]# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sda2[0]
      78043648 blocks [2/1] [U_]

md1 : active raid1 sda1[0]
      104320 blocks [2/1] [U_]

unused devices: <none>


Heres is the system disk output:

[root@server ~]# fdisk -l | more
Disk /dev/md1 doesn't contain a valid partition table
Disk /dev/md2 doesn't contain a valid partition table
Disk /dev/dm-0 doesn't contain a valid partition table
Disk /dev/dm-1 doesn't contain a valid partition table

Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   fd  Linux raid autodetect
/dev/sda2              14        9729    78043770   fd  Linux raid autodetect

Disk /dev/sdb: 80.0 GB, 80000000000 bytes
255 heads, 63 sectors/track, 9726 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1          13      104391   fd  Linux raid autodetect
/dev/sdb2              14        9726    78019672+  fd  Linux raid autodetect

Disk /dev/md1: 106 MB, 106823680 bytes
2 heads, 4 sectors/track, 26080 cylinders
Units = cylinders of 8 * 512 = 4096 bytes


Disk /dev/md2: 79.9 GB, 79916695552 bytes
2 heads, 4 sectors/track, 19510912 cylinders
Units = cylinders of 8 * 512 = 4096 bytes


Disk /dev/dm-0: 78.0 GB, 78014054400 bytes
2 heads, 4 sectors/track, 19046400 cylinders
Units = cylinders of 8 * 512 = 4096 bytes


Disk /dev/dm-1: 1879 MB, 1879048192 bytes
2 heads, 4 sectors/track, 458752 cylinders
Units = cylinders of 8 * 512 = 4096 bytes


Disk /dev/sdc: 250.0 GB, 250058268160 bytes
255 heads, 63 sectors/track, 30401 cylinder
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1       24283   195053166   83  Linux
/dev/sdc2           24284       30401    49142835   83  Linux
[root@server ~]#


So my question- how best to try and resolve the RAID issue so that I can VPN into the server?

[CharlieBrady]

From the output its clear the the second disk is not part of the RAID setup and the RAID setup is well "weird"?? A RAID array on one disk with two partitions??

No, that is not what you have, and what you have is not unusual for SME server. You have two RAID arrays, each with only one disk (part of a RAID1 degraded array). That is what is usually seen when you do a single disk install/

- correct to say that sdb is not being used.
- sdc is my USB backup disk.

Yes, it is correct to say that sdb is not being used. However, you cannot simply add sdb in to mirror sda, since it is a smaller disk (9726 cylinders versus 9729 cylinders). You need to buy a bigger disk, and install it as sdb, then partition it and add the partititions into the RAID arrays. Or you need to do some fancy footwork to shrink the partitions and LVM volumes on sda.

[ber]

Hi Charlie, as s supplementary to your post would it be an option to reformat sdb with equal or higher cylinder specs than sda. Then try and add this to the RAID config- will it "see" the new drive again and add it to the RAID automaticly or from the admin console prompt?

[CharlieBrady]

... would it be an option to reformat sdb with equal or higher cylinder specs than sda.

The disk is what it is. You can't make it bigger by reformatting it.