Subject: Raid 1 Issues
From: Leif Sawyer (lsawyer@gci.com)
Date: Fri Sep 13 2002 - 15:41:53 AKDT
I'm running 2.4.18, and trying to use Raid-1.
I created /etc/raidtab according to the instructions.
raiddev /dev/md0
raid-level 1
nr-raid-disks 2
nr-spare-disks 0
device /dev/hdc2
raid-disk 0
device /dev/hdb2
raid-disk 1
Next, I performed a raidsetup on my new disk (/dev/hdc2), and restarted. I
was
able to mount my new md0 with a single disk.
I then migrated all my data onto that new md0 and removed the old disk
(/dev/hdbX)
from /etc/fstab. I changed fstab to mount /dev/md0 as /usr and shutdown.
I removed the old /dev/hdb, and installed the new drive, a duplicate model
of /dev/hdc,
and restarted. I have no problems accessing /usr at this point, mounted
from /dev/md0.
I partitioned /dev/hdb to be exactly like /dev/hdc, and formatted it as
ext3.
I then used raidhotadd /dev/md0 /dev/hdb2 to try and add the new partition
to
my mirror.
"cat /proc/mdstat" shows the the devices connected, but not attached:
Personalities : [raid1]
read_ahead 1024 sectors
md0 : active raid1 ide/host0/bus0/target1/lun0/part2[1]
ide/host0/bus1/target0/lun0/part2[0]
77914752 blocks [1/1] [U]
unused devices: <none>
I waited for a while, installed some software, and then looked at
/proc/interrupts:
root@hedwig:~> cat /proc/interrupts
CPU0
0: 14635352 XT-PIC timer
14: 581245 XT-PIC ide0
15: 1341378 XT-PIC ide1
I have 2 disks on ide0,( / and /dev/hdb2), 2 disks on ide1 (/dev/hdc2 and
/dev/cdrom)
The difference in interrupts is really significant when moving data around.
ide0 doesn't
increment at the rate that ide1 does (nowhere close!) when accessing
/dev/md0 (mounted on /usr)
if I raidhotremove /dev/md0 /dev/hdb2, and then mount /dev/hdb2, there is
nothing on the
disk.
I've consulted the how-to without any success.
Thanks for any help or suggestions.
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This archive was generated by hypermail 2a23 : Fri Sep 13 2002 - 15:41:55 AKDT