Tips and Tricks site for advanced HP-UX Engineers

11 Jul 12 Online JFS filesystem expansion without umount

This requires add in software from Veritas/Symmantec that can be expensive on HP-UX.

Lets say we want to extend /var which is lvol8.

It was originally 600 LE and we extended it as follows.

lvextend -l 800 /dev/vg00/lvol8 /dev/disk/disk25_p2

The 800 refers to LE logical extents. I prefer to use this rather than MB because it corresponds to the values displayed by most lvm utilities. -L <value in megabytes> can be used. I assume you can do the math here.

[system099]/root # lvdisplay /dev/vg00/lvol8
— Logical volumes —
LV Name                     /dev/vg00/lvol8
VG Name                     /dev/vg00
LV Permission               read/write
LV Status                   available/syncd
Mirror copies               1
Consistency Recovery        MWC
Schedule                    parallel
LV Size (Mbytes)            12800
Current LE                  800
Allocated PE                1600
Stripes                     0
Stripe Size (Kbytes)        0
Bad block                   on
Allocation                  non-strict
IO Timeout (Seconds)        default

It was originally 600 LE and we extended it as follows.

lvextend -l 800 /dev/vg00/lvol8 /dev/disk/disk25_p2


fsadm -F vxfs -b 12800M /var

This command will use online JFS to extend the filesystem. The alternative is extendfs. But that requires a umount.  Or perhaps xvumount -o force. Your choice, I don’t recommend it, but did test it the other day in the sandbox.

Now if you want to be cute and use all your space, try this.

SIZE=$(lvdisplay /dev/vg00/lvol8 | awk ‘/LV Size/ {print $NF}’);


fsadm -F vxfs -b $ESIZE /var

You can get more cute and do it with a single command line but I’m not going to do that. I have not broken any systems this week and am trying to avoid that.

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