Re: problem splitting off a copy of a JFS2 filesystem ...

Hi ... yup, I wound up using the splitlvcopy command instead (along with making a snapshot). I was hoping to use the procedure listed in the IBM doc I linked to, because it seemed like, by doing so, I could avoid the unmounting of the source filesystem, the manual creation of the new /etc/filesystems entry, and the fsck of the newly split-off filesystem.

The IBM doc seemed to imply that doing the "chfs -a splitcopy ..." command would handle those needed steps automatically.

In any case, thanks for your reply. I wound up getting done what I needed for this particular case; it just took longer and was a bit more "manual" then i had hoped for.

-s-

On Apr 17, 2007, at 3:29 PM, Gergely Foti wrote:

Hi,

I tried right now on 5.3.0.4.4, and get the same result.

I used to use splitlvcopy, is it right for you?

# lsvg -l examplevg
examplevg:
LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
exampleloglv jfs2log 1 1 1 open/syncd N/A
examplelv jfs2 14 28 2 open/syncd /example
# umount /example
# splitlvcopy -y splitlv examplelv 1
splitlv
# lsvg -l examplevg
examplevg:
LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
exampleloglv jfs2log 1 1 1 closed/syncd N/A
examplelv jfs2 14 14 1 closed/syncd /example
splitlv jfs2 14 14 1 closed/syncd N/A
# vi /etc/filesystems
- where /example entry says
/example:
dev = /dev/examplelv
vfs = jfs2
log = /dev/exampleloglv
mount = false
account = false
- make an other entry for split, like:
/split:
dev = /dev/splitlv
vfs = jfs2
log = /dev/exampleloglv
mount = false
account = false

-then write, and:
# mount /example
# mkdir /split
# mount /split
# df -m | egrep "split|examp"
/dev/examplelv 896.00 895.54 1% 4 1% /example
/dev/splitlv 896.00 895.54 1% 4 1% /split

If you want to make a secondary lv copy, you have to use mklvcopy, you cannot join the split copy.
If you have 2 copies of each lv, including the jfs2log, you can try split the volume group (splitvg), if it's an opportunity (it can be joined later with joinvg).

Regards,
Gergely

Sandor W. Sklar wrote:
I'm trying to split off a mirrored copy of a logical volume and mount it as a separate (read-only ) filesystem, as described on the page:

<http://publib.boulder.ibm.com/infocenter/pseries/v5r3/ index.jsp?topic=/com.ibm.aix.baseadmn/doc/baseadmndita/ HT_baseadmn_snapshotjfs.htm>

... but it isn't working. That page says it should work on AIX 5.2, but here's what I've got:

#> df /s
Filesystem 512-blocks Free %Used Iused %Iused Mounted on
/dev/lv21 209715200 65659248 69% 343096 5% /s

#> lsfs -q /s
Name Nodename Mount Pt VFS Size Options Auto Accounting
/dev/lv21 -- /s jfs2 209715200 rw yes no
(lv size: 209715200, fs size: 209715200, block size: 4096, sparse files: yes, inline log: yes, inline log size: 400, reserved: 0, reserved: 0, DMAPI: no, VIX: no)

#> lslv lv21
LOGICAL VOLUME: lv21 VOLUME GROUP: emcvg
LV IDENTIFIER: 0001dcba00004c00000001047c9fe1c4.5 PERMISSION: read/write
VG STATE: active/complete LV STATE: opened/ syncd
TYPE: jfs2 WRITE VERIFY: off
MAX LPs: 512 PP SIZE: 512 megabyte(s)
COPIES: 2 SCHED POLICY: parallel
LPs: 200 PPs: 400
STALE PPs: 0 BB POLICY: relocatable
INTER-POLICY: minimum RELOCATABLE: yes
INTRA-POLICY: middle UPPER BOUND: 128
MOUNT POINT: /s LABEL: /s
MIRROR WRITE CONSISTENCY: on/ACTIVE
EACH LP COPY ON A SEPARATE PV ?: no
Serialize IO ?: NO

#> lsvg -l emcvg | grep lv21
lv21 jfs2 200 400 2 open/syncd /s
#> mkdir /s_copy

#> df /s_copy
Filesystem 512-blocks Free %Used Iused %Iused Mounted on
/dev/hd4 2621440 1475112 44% 3852 1% /
#> chfs -a splitcopy=/s_copy /s

#> echo $?
0

#> df /s_copy
Filesystem 512-blocks Free %Used Iused %Iused Mounted on
/dev/hd4 2621440 1475112 44% 3852 1% /


Note that the "chfs" command returns no error, and exits "0". The split never happens though. Am I missing some crucial but non- obvious step here? This system is at:

#> oslevel -s
5200-09-04

... so I'm fairly up to date. Thanks in advance for the help ... I've never done this before!

-s-