[linux-lvm] alternative to pvmove on root volume

[Stuart D. Gathman]

On Thu, 28 Jan 2010, malahal at us.ibm.com wrote:

> > given that pvmove also works by mirroring I'm not convinced I haven't
> > just been lucky so far .  So does anyone have any ideas or even better
> > experiance on whether this is likely to work or am I setting myself up
> > for a world of pain if I try it on a live server?
> 
> Yes, pvmove works very similar. It will create a mirror for each segment
> one at a time, so it may have to create lot more mirrors depending on
> your configuration. If it ends up needing more 'lvconverts' (suspends),
> then the probability of failure (deadlock) will increase.

It seems to me, that if disk space is available, pvmove could minimize
metadata updates by mirroring as many LEs as possible at once.  This
would reduce to the equivalent of mirroring then reducing the entire LE
when space is available.  What happens in case of memory log and crash,
however?  Does it still remember which mirror is the "original"?

-- 
	      Stuart D. Gathman <stuart at bmsi.com>
    Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
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