vinum rebuildparity, when?

[Christian Laursen]

Stijn Hoop <stijn at win.tue.nl> writes:

> I was wondering about the vinum 'rebuildparity' command, especially the
> times when one needs to use this.

I run rebuildparity if checkparity finds any errors after unclean shutdowns.

> The problem is that I can't find anything in the vinum docs about this
> command other than it's purpose. What I don't understand is the difference
> between reviving a disk in a RAID-5 plex, and rebuilding the parity.

When reviving a disk the data on that disk is calculated from the data and the
parity on the other disks. I think rebuildparity only reads data and writes
the parity calculated from that but for all disks.

> When I start a degraded disk it starts to revive -- which led me to believe
> that vinum was also recalculating the parity. Evidently it wasn't.
> I'm therefore now updating my procedures to always run 'checkparity -v <plex>'
> after a disk crash.

That shouldn't be neccesary.

> Does anyone know if this is supposed to be this way?

I'm pretty sure, that it isn't.

-- 
Christian Laursen