[linux-lvm] LE/PE Question

[Steven Lembark]

-- "Heinz J . Mauelshagen" <mauelshagen at sistina.com>

>> The unit of failure, for all pratical purposes, is the LV
>> (unless you are into using dd on raw disk devices to make
>> your backups). If one drive is likely to fail then any LV
>> crossing that LV is going to get fried (short of RAID) and
>> will have to be restored.
>
> With LVM2 (and deprecated LVM1.1) you are able to activate a VG even
> though some of its PVs are inaccessable.
> If any filesystem is mountable still depends on the availability
> of alternate superblocks and (at least) the root directory.

Which seems to mean that the unit of failure still is
the LV: if an LV spans PV's and the PV looses data then
the LV is unusable. The VG being able to survive an offline
PV is a Very Good Thing but doesn't do anything to help
someone with a filesystem on an LV with half its extents
missing.


--
Steven Lembark                               2930 W. Palmer
Workhorse Computing                       Chicago, IL 60647
                                            +1 800 762 1582