[Wylug-help] help with RAID
Roger Beaumont
roger.bea at blueyonder.co.uk
Sun Jan 28 21:54:26 GMT 2007
I've got a pair of drives configured as raid-1. Now read on...
They are getting full, so I got a new pair of 250gig SATA drives. The plan
was to configure those too as raid-1, then add them in linear mode to the
md partition that's filling up (plan derived courtesy of info on the
Software-RAID.HOWTO at unthought.net).
Step 1 was to look at /proc/mdstat to see that the existing pair were OK.
They weren't. After extensive web browsing and use of 'mdadm --detail' and
the manufacturer's diagnostic tool (which says the drive is perfect) it
seems that the problem wasn't the drive itself, but a dodgy power lead that
made it cut out. However, the RAID software is now convinced the drive is
duff.
I'll probably be back again for more help (the guy who set it up for me
originally has moved), but for now I just want to know how to get the
existing raid to re-synch, so that at least the existing stuff is all safe
again.
What else do I need to tell you?
The version of mdadm currently installed is 1.8.1 (yum says 1.12.0-1.caos
is available, but my FC-5 workstation has 2.3.1)
There is no /etc/raidtab file.
The only un-commented-out line in /etc/mdadm.conf is
------------------
MAILADDR root
------------------
>df
gives:
------------------
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/md0 1881568 971396 814592 55% /
/dev/md1 241036 7594 220998 4% /boot
/dev/md3 4237632 2473196 1549172 62% /usr
/dev/md4 932792 16484 868924 2% /tmp
/dev/md5 932792 175084 710324 20% /var
/dev/md6 932792 304588 580820 35% /var/cache
/dev/md7 458800 55095 380016 13% /var/log
/dev/md8 170297264 157843988 3802684 98% /space
------------------
(It is md8 to which I want to add the new drive pair in linear mode, but
more of that later.)
>fdisk -l /dev/hdc
(the active disk) gives:
------------------
Disk /dev/hdc: 200.0 GB, 200049647616 bytes
255 heads, 63 sectors/track, 24321 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hdc1 1 32 257008+ fd Linux raid autodetect
/dev/hdc2 33 282 2008125 fd Linux raid autodetect
/dev/hdc3 283 402 963900 fd Linux raid autodetect
/dev/hdc4 403 24321 192129367+ 5 Extended
/dev/hdc5 403 1027 5020281 fd Linux raid autodetect
/dev/hdc6 1028 1152 1004031 fd Linux raid autodetect
/dev/hdc7 1153 1277 1004031 fd Linux raid autodetect
/dev/hdc8 1278 1402 1004031 fd Linux raid autodetect
/dev/hdc9 1403 1465 506016 fd Linux raid autodetect
/dev/hdc10 1466 24321 183590788+ fd Linux raid autodetect
------------------
>fdisk -l /dev/hda
(the inactive disk) gives:
------------------
Disk /dev/hda: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/hda1 1 238 1911703+ fd Linux raid autodetect
/dev/hda2 239 269 249007+ fd Linux raid autodetect
/dev/hda3 270 384 923737+ fd Linux raid autodetect
/dev/hda4 385 30401 241111552+ 5 Extended
/dev/hda5 385 920 4305388+ fd Linux raid autodetect
/dev/hda6 921 1038 947803+ fd Linux raid autodetect
/dev/hda7 1039 1156 947803+ fd Linux raid autodetect
/dev/hda8 1157 1274 947803+ fd Linux raid autodetect
/dev/hda9 1275 1333 473886 fd Linux raid autodetect
/dev/hda10 1334 22872 173011986 fd Linux raid autodetect
/dev/hda11 22873 30401 60476661 83 Linux
------------------
>mdadm --detail /dev/md0
gives
------------------
/dev/md0:
Version : 00.90.01
Creation Time : Sun Jul 3 20:03:50 2005
Raid Level : raid1
Array Size : 1911616 (1866.81 MiB 1957.49 MB)
Device Size : 1911616 (1866.81 MiB 1957.49 MB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Sun Jan 28 21:48:06 2007
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 6b8b4567:327b23c6:643c9869:66334873
Events : 0.4415723
Number Major Minor RaidDevice State
0 22 2 0 active sync /dev/hdc2
1 0 0 - removed
------------------
>mdadm --detail /dev/md1
gives
------------------
/dev/md1:
Version : 00.90.01
Creation Time : Sun Jul 3 20:03:50 2005
Raid Level : raid1
Array Size : 248896 (243.06 MiB 254.87 MB)
Device Size : 248896 (243.06 MiB 254.87 MB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 1
Persistence : Superblock is persistent
Update Time : Sun Jan 28 21:41:31 2007
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 6b8b4567:327b23c6:643c9869:66334873
Events : 0.3835
Number Major Minor RaidDevice State
0 22 1 0 active sync /dev/hdc1
1 0 0 - removed
------------------
>mdadm --detail /dev/md8
gives
------------------
/dev/md8:
Version : 00.90.01
Creation Time : Sun Jul 3 20:04:08 2005
Raid Level : raid1
Array Size : 173011904 (164.100 GiB 177.16 GB)
Device Size : 173011904 (164.100 GiB 177.16 GB)
Raid Devices : 2
Total Devices : 1
Preferred Minor : 8
Persistence : Superblock is persistent
Update Time : Sun Jan 28 21:47:38 2007
State : clean, degraded
Active Devices : 1
Working Devices : 1
Failed Devices : 0
Spare Devices : 0
UUID : 6b8b4567:327b23c6:643c9869:66334873
Events : 0.3342355
Number Major Minor RaidDevice State
0 22 10 0 active sync /dev/hdc10
1 0 0 - removed
------------------
Is that enough info? ;^)
TIA,
Roger
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