Software RAID Configuration problem

[Mathew Snyder]

You are correct.  my RAID array isn't starting.  During boot I get this:
Starting up RAID devices: /dev/md0(skipped)

Once I log in I can run `raidstart /dev/md0` and it comes up fine after
which I am able to mount directories to it.  Why wouldn't it start up
during boot?

I looked at that article but it basically explains how to create an
array using mdadm instead of raidtools.  It didn't really offer much
help in the way of getting it to start on boot.

Mathew

Ron McKeever wrote:
> I don't think your problem is labels, I think it is that your RAID array
> isn't starting when mounting occurs. When you created /dev/sdb4 is it the
> same size as /dev/sda3? What does /proc/mdstat show?
> These might help:
> http://kbase.redhat.com/faq/FAQ_43_2812.shtm
> 
> 
> -----Original Message-----
> From: redhat-sysadmin-list-bounces at redhat.com
> [mailto:redhat-sysadmin-list-bounces at redhat.com] On Behalf Of Mathew Snyder
> Sent: Friday, October 27, 2006 9:04 PM
> To: redhat-sysadmin-list at redhat.com
> Subject: Re: Software RAID Configuration problem
> 
> I logged in and ran `mount /home` and got mount: no such partition
> found.  I then checked the label on /dev/md0 but is came back with:
> e2label: invalid argument while trying to open /dev/md0
> Couldn't find valid filesystem superblock.
> 
> Mathew Snyder
> 
> Ron McKeever wrote:
>> Rename /dev/sda3 and /dev/sdb4 with something other that /home, then label
>> /dev/md0 as /home... 
>>
>> You could also try the full syntax in /etc/fstab instead of the
> LABEL=/home,
>> like:
>> /dev/md0 /home ext3 defaults 1 2
>>
>> Ron
>>
>> -----Original Message-----
>> From: redhat-sysadmin-list-bounces at redhat.com
>> [mailto:redhat-sysadmin-list-bounces at redhat.com] On Behalf Of Mathew
> Snyder
>> Sent: Friday, October 27, 2006 7:28 PM
>> To: redhat-sysadmin-list at redhat.com
>> Subject: Software RAID Configuration problem
>>
>> I posted this to rhn-users before realizing there is an actual sysadmin
>> list so I'm posting it here now.
>>
>> I have an RHEL 4 AS virtual machine running under VMWare with the
>> following configuration:
>>
>> /dev/sda1 /     650M
>> /dev/sda2 /var  500M
>> /dev/sda3 /home 500M (Linux raid autodetect for software raid)
>> /dev/sda4 Extended partition
>> /dev/sda5 swap  128M
>>
>> /dev/sdb1 /usr  1.65G
>> /dev/sdb2 /tmp  100M
>> /dev/sdb3 Linux raid autodetect for software raid with /dev/sda3)
>>
>> Here's the run down:  I started with a single /home partition on
>> /dev/sda and plenty of unallocated space on /dev/sdb.  I followed
>> directions in Michael Jang's RHCE book for mirroring the /home
>> partition.  They are as follows:
>>
>> Copy the /home data to /tmp then
>>
>> # unmount /home
>> # fdisk /dev/sda
>> Command (m for help) : t
>> Partition number (1-4)
>> 3
>> Partition ID (L to list options): FD
>> Command (m for help) : w
>>
>> # fdisk /dev/sdb
>> Command (m for help) : t
>> Partition number (1-4)
>> 4
>> Partition ID (L to list options): FD
>> Command (m for help) : w
>>
>> I then edit /etc/raidtab and add the following information:
>> raiddev /dev/md0
>> raid-level 1
>>
>> nr-raid-disks 2
>> nr-spare-disk 0
>> persistent-superblock 1
>> chunck-size 4
>> device /dev/sda3
>> raid-disk 0
>> device /dev/sdb4
>> raid-disk 1
>>
>>
>> I then create the raid and format it:
>> # mkraid -R /dev/md0 (this runs to completion with no errors)
>> # mkfs -j /dev/md0
>>
>> I then run e2label so I can apply a label to /dev/md0 and use the
>> LABEL=/home entry in /etc/fstab.  However, when I reboot it says it
>> can't mount the special device: LABEL=/home no such device, etc.
>>
>> When I log in, I run e2label on /dev/md0 and it isn't found.  If I run
>> e2label on either /dev/sda3 or /dev/sdb4 it comes back with /home.
>>
>> If I mount /dev/md0 it mounts fine.
>>
>> I've changed the format command to `mke2fs -j -L /home /dev/md0`
>> thinking it would give me better results but they end up the same.  It
>> won't mound /dev/md0 based on the label alone.
>>
>> What might I be doing wrong?
>>
>> Thanks,
>> Mathew Snyder
>>
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