Topic: Software RAID

[Ken Easley]

I installed the SME Server using two Western Digital WDE 4360 scsi harddrives on an Adaptec 2940 adaptor.  The second harddrive died (will not spin up upon reboot).  I replaced the Harddrive with another WDE 4360 that has been low level formated.  What is the procedure to reestablished the software raid 1?  I did see messages that the recovery of the raid failed due to SME Server could not find any other harddrives to use.

I am guessing that I need to create a file system on the new drive and the when the system reboots it will see the drive and redo the RAID 1 that I did implement.  I asked this so I did not have to redo the whole server.

I do have recent backups and reinstallation disk for the server.  

What would be faster easier for 5 node network.

Thanks for all your help:)

Ken

[Dan G.]

Darrell used to have an excellent how-to on his site, and the link still exists in the Contributed How-tos section of e-smith.org --- but it seems to be gone.

Darrell, we miss it

Dan

[Dan Brown]

You'll find Darrell's guides at http://myezserver.com/downloads/mitel/howto/.  However, guides which relate to particular RPMs seem to be filed with those RPMs; so the raidmonitor HOWTO is in http://myezserver.com/downloads/mitel/contrib/raidmonitor-0.0.1/.  Very confusing layout, I'm afraid.

[Franck]

Maybe http://www.linuxdoc.org/HOWTO/Software-RAID-HOWTO.html could help you )

[Harvey M.]

It's Mitel's product... I'm sure that they have instructions on how to repair a failed hard drive!

[ClaudioG]

From the Mitel How-to (i test this on Ide raid and work fine):

--------------------

At a convenient time, shutdown your e-smith server and replace the faulty disk. The new disk should have the same geometry as both the old disk and the current working disk.

Boot the e-smith server.

Switch to a login prompt (press Alt+F2 if you are viewing the console) and login as root.

Partition the new disk. It should be partitioned exactly the same as the other disk. Use the following command to determine the current partition details for the working disk /dev/hdc:

   fdisk -l /dev/hdc

 

You should see details similar to:

   
   Disk /dev/hdc: 64 heads, 63 sectors, 1015 cylinders
   Units = cylinders of 4032 * 512 bytes

      Device Boot    Start       End    Blocks   Id  System
   /dev/hdc1   *         1       131    264064+  fd  Linux raid autodetect
   /dev/hdc2           132      1015   1782144    5  Extended
   /dev/hdc5           132       137     12064+  fd  Linux raid autodetect
   /dev/hdc6           138      1015   1770016+  fd  Linux raid autodetect

 

Set up the identical partitions on /dev/hda using the command

   fdisk /dev/hda

 

Use the fdisk -l command to double check to make sure the partitions are exactly the same as those on the working disk, /dev/hdc.

Determine which partitions have been mirrored. Look at the file /proc/mdstat, where you should see something like this (note that this file is from a working system and not one that has failed):

   # cat /proc/mdstat
   Personalities : [raid1]
   read_ahead 1024 sectors
   md2 : active raid1 hdc1[1] hda1[0] 264000 blocks [2/2] [UU]
   md0 : active raid1 hdc5[1] hda5[0] 11968 blocks [2/2] [UU]
   md1 : active raid1 hdc6[2] hda6[0] 1769920 blocks [2/2] [UU]
   unused devices:

 

This file indicates that you have three "meta-devices" that are mirrored:

md0 - using hdc5 and hda5

md1 - using hdc6 and hda6

md2 - using hdc1 and hda1

Re-attach the partitions from the new disk to the RAID devices:

   /sbin/raidhotadd /dev/md0 /dev/hda5
   /sbin/raidhotadd /dev/md1 /dev/hda6
   /sbin/raidhotadd /dev/md2 /dev/hda1

 

You can see the progress of the raid resyncronization by examining /proc/mdstat. The following example output shows that both /dev/md0 and /dev/md2 are fully synchronized and /dev/md1 is 58% synchronized.

   # cat /proc/mdstat
   Personalities : [raid1]
   read_ahead 1024 sectors
   md2 : active raid1 hdc1[1] hda1[0] 264000 blocks [2/2] [UU]
   md0 : active raid1 hdc5[1] hda5[0] 11968 blocks [2/2] [UU]
   md1 : active raid1 hdc6[2] hda6[0] 1769920 blocks [2/1] [U_] recovery=58% finish=2.6min
   unused devices:

------------------------

Regards,
ClaudioG

[Ken Easley]

Everybody,

Thank you!!!!:)  All of your suggestions and recommendations was/is on the mark and it is done.  Not as hard as I thought it would be.  I could have just installed a new disk and reinstall the OS but I did follow your suggestions and did it.  That was fun (really, no pun), learned alot the last few days.

Again my sincere appreciation goes out to you all.

Ken