lewis shobbrook wrote:
Hi All,
I'm wondering if anyone has discovered any nice tricks to assist in
identification of hdd devices.
I have an 8 bay hotswap array, pretty lights and have been wondering
what others out there might be doing to determine which disk in an
array is which.
I've noted that device allocation can change with the generation of
new initrd's and installation of new kernels; i.e. /dev/sdc becomes
/dev/sda depending upon what order the modules load etc.
I'm wondering if one could send a looped read/write task to a swap
partition or something to determine which the device is?
The device UUID in the RAID superblock doesn't change across a reboot.
If you run mdadm --examine on the disk, you should see something like
[root@ss-110 root]# mdadm --examine /dev/sda
/dev/sda:
Magic : a92b4efc
Version : 01
Feature Map : 0x0
Array UUID : eab59421:6ddd9761:05e6ca46:d2342b03
Name : 408088ETX1:single
Creation Time : Mon Dec 4 21:25:55 2006
Raid Level : raid1
Raid Devices : 2
Device Size : 117210096 (55.89 GiB 60.01 GB)
Array Size : 117187500 (55.88 GiB 60.00 GB)
Used Size : 117187500 (55.88 GiB 60.00 GB)
Super Offset : 117210224 sectors
State : active
==>Device UUID : 06795ada:d2fb18a1:2e7de09f:af66a7e3 <==
Update Time : Thu May 24 11:49:21 2007
Checksum : 7a695b9f - correct
Events : 4346975
That number should always uniquely identify your disks.
Maybe even a better way is to run:
[root@ss-110 root]# smartctl -d ata /dev/sda -i
smartctl version 5.36 [i686-pc-linux-gnu] Copyright (C) 2002-6 Bruce Allen
Home page is http://smartmontools.sourceforge.net/
=== START OF INFORMATION SECTION ===
Device Model: FUJITSU MHV2060BH
====> Serial Number: NW02T6826LM5 <====
Firmware Version: 00000028
User Capacity: 60,011,642,880 bytes
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: 7
ATA Standard is: ATA/ATAPI-7 T13 1532D revision 4a
Local Time is: Thu May 24 11:51:16 2007 EDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
That serial number never changes, even if you wipe the disk.
Colin
Cheers,
Lew
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
