mirrored metadevice as swap
I have a solaris8 server with a swap device (file) that is a mirrored metadevice (/dev/md/dsk/d1). swap -l reports 20484272 blocks, which = about 10GB. format says slice 1 is 9.77 GB. To me this means that the system is treating the metadevice as a mirror, which it is.
Is the OS really mirroring it's swap? That seems unnecessary and inefficient.
If this is the case, can I safely detach one of the sub-mirrors without affecting my system? Will it continue operating with 10GB swap?
Thanks.
# 1
Yes, if you have mirrored disk as swap then you can dettach a submirrror "safely" in that the machine will continue operating just fine.
However at any time in the future if the remaining swap disk fails, your machine will crash.
And may well randomly corrupt other filesystems on the way down..
So how much do you value good uptime and your data.
# 2
Its a good idea to mirror the swap, the reason being that if you only have the swap on one of the disk and that disk break you will loose your swap contents, which includes swapfs and swaped processes/LWPs, which is not a good thing.
Also, in theory, since you have a mirrored swap you will have two disks and hence improving the performance of the swap.
.7/M.
