[CentOS] How to enable my RAID again

Theo Band theo.band at xanadu-wireless.com
Fri Oct 5 09:04:59 UTC 2007


Hi

I have setup software RAID two years ago using FC3 using the graphical
installer (RAID1). In the mean time I installed CENTOS4.5 and everything
is running fine. At least that was my perception. It now turns out that
raid is not working and that LVS just finds 4 partitions from four disks
and that's it.:

  /dev/sda2  VolGroup00 lvm2 a-   94.88G     0
  /dev/sdb1  VolGroup00 lvm2 a-   94.94G 10.00G
  /dev/sdc1  VolGroup00 lvm2 a-   94.94G 74.94G
  /dev/sdd1  VolGroup00 lvm2 a-   94.94G 70.81G

These are 4 disk of each 200GB, and the disks have these partitions:

Using /dev/sda
(parted) print
Disk geometry for /dev/sda: 0.000-194481.000 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031    101.975  primary   ext3        boot
2        101.975  97284.243  primary               lvm
3      97284.243 194474.355  primary               raid
Disk geometry for /dev/sdb: 0.000-194481.000 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031  97237.177  primary               boot, lvm
2      97237.178 194474.355  primary               raid
Disk geometry for /dev/sdc: 0.000-194481.000 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031  97237.177  primary               boot, lvm
2      97237.178 194474.355  primary               raid
Disk geometry for /dev/sdd: 0.000-194481.000 megabytes
Disk label type: msdos
Minor    Start       End     Type      Filesystem  Flags
1          0.031  97237.177  primary               boot, lvm
2      97237.178 194474.355  primary               raid

So my feeling is that I need to setup the RAID again, but I don't want
to make any mistakes here, since this is a live system working fine. I
tried to read the mdadm manual but it's not quit clear to me what to do.
# mdadm -A --scan -v
mdadm: No arrays found in config file

Shows I have to do more. The previous fedora installation is still
around, but is doesn't contain a /etc/mdadm.conf file.

Can anyone help me with some steps to take to get it running again. I do
have backups, but if things go wrong restoring takes several hours.

Thanks,
Theo


PS.
Send for the third time. Could it be that posting is limited to email
addresses that are subscribed to the list?



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