Faster SVM mirror resync
With Solaris Volume Manager (SVM), RAID 1 volumes (mirroring) can benefit from increased sync buffer_size of 1M. The default settings in Solaris Volume Manager can lead to pretty long resync times, and the way to speed it up is [taken straight out of the metasync(1M) manpage]
There are two way to change block size to get quickly synchronized disks in mirrored system
via command-line
Use the metasync -r buffer_size
buffer_size Specifies the size (number of 512-byte disk blocks) of the internal copy buffer for the mirror resync. The size defaults to 128 512-byte disk blocks (64 Kbytes). It can be no more than 2048 blocks. For best performance (quickest completion of the resync), 2048 blocks is the recommended size.
For example:
# metasync -r 2048
For permanent changes
- Solaris 8 / Solaris 9
Edit the
/etc/rc2.d/S95svm.sync
file to include the 2048 buffer_size. - Solaris 10
- Add the following line to
/etc/system
, setmd_mirror:md_resync_bufsz = 2048
- Perform a system reboot
- Add the following line to
NOTE:
- The maximum buffer_size is 2048
- Increasing the value will may lead low I/O performance.