[linux-lvm] Powerfailure and snapshot consistency

[Stuart D. Gathman]

On Fri, 25 Mar 2011, Ron Johnson wrote:

> On 03/25/2011 11:24 PM, Stuart D. Gathman wrote:
> [snip]
>> 
>> 2) make sure important LVs do not span multiple PVs (except for LVM
>> mirroring) - you could be unhappy in the event of a system crash.
>> 
>
> But isn't "volumes larger than physical devices" (one of) the raison d'etre 
> of LVM?

Yes, but a power failure can then mess up the ordering of write completions
distributed between 2 or more PVs, which could defeat the assumptions made
by your file system journaling.

and

No, YMMV, but I generally have a number of smaller LVs (for virtual machines)
and it is nice to have a larger pool of PVs from which they are allocated.

--
 	      Stuart D. Gathman <stuart at bmsi.com>
     Business Management Systems Inc.  Phone: 703 591-0911 Fax: 703 591-6154
"Confutatis maledictis, flammis acribus addictis" - background song for
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