LVM resize sanity check

[brian]

Craig White wrote:
> On Wed, 2008-10-22 at 11:42 -0400, brian wrote:
>> ...
 >>
>> I'd like to reduce /var first to free up some space, then give that
>> to /tmp using:
>> 
>> # umount /var # e2fsck -f /dev/VolGroup00/LogVol04 # resize2fs
>> /dev/VolGroup00/LogVol04 13G # lvreduce -L-6G
>> /dev/VolGroup00/LogVol04 # mount /var # umount /tmp # e2fsck -f
>> /dev/VolGroup00/LogVol03 # lvextend -L+6G /dev/VolGroup00/LogVol03 
>> # resize2fs /dev/VolGroup00/LogVol03 # mount /tmp
>> 
>> Does that ring any alarm bells?
>> 
>> [1] http://www.tldp.org/HOWTO/LVM-HOWTO/
> ---- I don't know about alarm bells but I would think that you would
> have to 'lvmove' LogVol04 to make contiguous space for LogVol03
> 
> frequent usage of things like lvdisplay can give you some good clues
> on where things are
> 

I have no lvmove here. I have lvm2-2.02.24-1.fc7 installed. Did you mean 
pvmove? I'm looking at the man page now but the lightbulb remains dark. 
Can you elaborate on that?

I've also been reading this guide:
http://www.ibm.com/developerworks/library/l-lvm2/?ca=dgr-lnxw02LinuxLVM2&S_TACT=105AGX59&S_CMP=GR

Here's the mapping:

# lvdisplay -m /dev/VolGroup00/LogVol03
   --- Logical volume ---
   LV Name                /dev/VolGroup00/LogVol03
   VG Name                VolGroup00
   LV UUID                yTInlj-Gr3z-2kkZ-YrmT-to5g-gXrj-pxNPBV
   LV Write Access        read/write
   LV Status              available
   # open                 1
   LV Size                992.00 MB
   Current LE             31
   Segments               1
   Allocation             inherit
   Read ahead sectors     0
   Block device           253:4

   --- Segments ---
   Logical extent 0 to 30:
     Type                linear
     Physical volume     /dev/sda2
     Physical extents    2187 to 2217


# lvdisplay -m /dev/VolGroup00/LogVol04
   --- Logical volume ---
   LV Name                /dev/VolGroup00/LogVol04
   VG Name                VolGroup00
   LV UUID                NWt5s8-27ZK-nGU0-DM2u-zkxm-VoJe-v0XGHD
   LV Write Access        read/write
   LV Status              available
   # open                 1
   LV Size                19.53 GB
   Current LE             625
   Segments               1
   Allocation             inherit
   Read ahead sectors     0
   Block device           253:3

   --- Segments ---
   Logical extent 0 to 624:
     Type                linear
     Physical volume     /dev/sda2
     Physical extents    1562 to 2186


So, from what I can make out, it seems that the PEs of LogVol04 come 
*before LogVol03, which seems a bit strange.

(Incidentally, it's a bit disconcerting that google shows, "Restore 
after lvmove crash" for the first several entries for "lvmove".)