Replacing a faulted disk in a SVM - hotswap

Lets see how to replace a defective disk which is in 'Maintenance' state in SVM.

This is a hot swap in which the old failed disk is pulled out of the live system and a new disk is attached back into it. Before removing a disk, it must be un-configured from SVM.

The disk is part of a concatenated mirror. Six disks are organized as mirror with 3 disks forming a concatenation at each ends.

Mirror - d6
Sub-Mirror 1 - d15
Sub-Mirror 2 - d16

           d 6
           | |
           | |
       d15 | | d16


One of the failed disk is in the sub-mirror d16. To replace, we need to detach the sub-mirror, clear the sub-mirror, replace the disk, recreate the sub-mirror.

Step-1

$metadetach d6 d16
[Once detached, the logging device is no longer part of the trans, thus the trans is no longer logging and all benefits of logging are lost. Use the -f option if the device is busy. Use it only if the disk is in maintenance state]
$metadetach -f d6 d16

Step-2

$metaclear d16

[The metaclear command deletes the specified metadevice or deletes all hotspares/soft partitions. Once cleared, we need to create again using metainit to be able to use again]

Step-3

Here the disk is pulled out and the new disk is inserted. Necessary un-configuration is done using cfgadm and after replacement, then action is taken to recognize the disk at oS level.

$cfgadm -al

Step-4

The new attached disk is now formatted similar to the opposite sub-mirrors configuartion.

$prtvtoc /dev/dsk/c2t1d0s2|fmthard -s - /dev/rdsk/c0t1d0s2 

[Copy the VTOC from old disk to new using fmthard command]

Step-5

$metainit d16 3 1 c0t0d0s6 1 c0t1d0s2 1 c0t2d0s2
[Recreate the sub-mirror using metainit]

Step-6

$metattach d6 d16

[This reattaches the other sub-mirror and immediately starts the synchronization of data from the other sub-mirror]

Step-7

$metastat -C

[This checks the metadevice states]