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Legacy Forums => Experienced User Forum => Topic started by: Ken Easley on March 25, 2002, 06:40:48 PM

Title: Software RAID
Post by: Ken Easley on March 25, 2002, 06:40:48 PM: 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
Title: Calling Darrell May...
Post by: Dan G. on March 25, 2002, 06:56:02 PM: 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
Title: Re: Calling Darrell May...
Post by: Dan Brown on March 25, 2002, 07:03:45 PM: 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.
Title: Re: Software RAID
Post by: Franck on March 25, 2002, 07:07:01 PM: Maybe http://www.linuxdoc.org/HOWTO/Software-RAID-HOWTO.html could help you :o)
Title: Re: Software RAID
Post by: Harvey M. on March 25, 2002, 07:55:29 PM: It's Mitel's product... I'm sure that they have instructions on how to repair a failed hard drive!
Title: Re: Software RAID
Post by: ClaudioG on March 27, 2002, 09:01:11 PM: 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
Title: Re: Software RAID
Post by: Ken Easley on March 28, 2002, 07:34:43 PM: 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