From: Green, Simon (SGreen@KRAFTEUROPE.COM)
Date: Mon Sep 09 2002 - 11:30:40 EDT
I've had this situation myself, but only with older versions of AIX,
(possibly 4.3.2?) and not on paging spaces. It happens when you extend a
mirrored LV. You can avoid it with super-strict allocation, or by
explicitly specifying where mirror copies go. I thought that 4.3.3 was
smart enough to avoid it (unless you did it deliberately) but I'm not sure
about that. It's worth noting that the default strictness only says that
each individual LP copy must be on a different disk; it doesn't say anything
about the LV copy as a whole and will not prevent this sort of
inter-twining.
In terms of availability, you'll be OK: if you lose hdisk0 you've still got
a valid copy of each partition. It might be awkward recovering from that,
and it makes managing things a bit harder.
The best way to recover from it would be to drop one copy, without
specifying which disk the copy is on, then use migratepv to get the
remaining PPs onto a single disk and finally rebuild your mirror. If you've
got the spare disk capacity you might prefer to add a third copy on new
disk(s) before dropping one of the old ones.
I would advise you to sort things out as quickly as possible. All of this
can be done whilst the LV is in use, but obviously if you drop a copy you
run a slight risk so you may to prefer to do it whilst the system is not in
use.
To prevent it in future, superstrict allocation, (chlv -s s). For a normal
filesystem, you could use a map file with extendlv; I'm not sure what you'd
do with a paging space.
I've seen that "Illegal parameter or structure value" when trying to run
extendlv, fairly recently. I got around it by specifying a map file. I
suspect that you're going to have to sort out the mirrors using the
technique above - or some other technique - before reorgvg would work.
Better not to use that anyway: if you're prepared to take the possible hit
on availability, it's quicker to drop a mirror copy and re-build it than to
run reorgvg, in my experience.
Simon Green
Philip Morris ITSC Europe
AIX-L Archive at http://marc.theaimsgroup.com/?l=aix-l&r=1&w=2
AIX FAQ at http://www.faqs.org/faqs/aix-faq/
N.B. Unsolicited email from vendors will seldom be appreciated.
> -----Original Message-----
> From: Jan-Frode Myklebust [mailto:janfrode@PARALLAB.UIB.NO]
> Sent: 09 September 2002 14:43
> To: aix-l@Princeton.EDU
> Subject: mirrored pagespace, LPs on same PV
>
> My mirrored pagespace seems to be broken:
>
> # lslv -m hd6 | egrep 'hdisk0.*hdisk0|hdisk1.*hdisk1'
> 0004 0113 hdisk1 0410 hdisk1
> 0116 0051 hdisk0 0055 hdisk0
> 0117 0052 hdisk0 0114 hdisk0
> 0122 0232 hdisk1 0227 hdisk1
> 0124 0234 hdisk1 0412 hdisk1
> # lsps -a
<SNIP>
> # lslv hd6
<SNIP>
> EACH LP COPY ON A SEPARATE PV ?: yes
>
> and I thought 'reorgvg' should fix this, but it complains about
> 'Illegal parameter or structure value':
>
> tre# reorgvg rootvg hd6
> 0516-022 lmigratepp: Illegal parameter or structure value.
> 0516-964 reorgvg: Unable to migrate logical volume hd6.
> 0516-968 reorgvg: Unable to reorganize volume group.
>
> Could somebody explain why some LPs copies are on the same PV as the
> original, and why 'reorgvg' isn't able to fix this?
This archive was generated by hypermail 2.1.7 : Wed Apr 09 2008 - 22:16:11 EDT