extend mirrored /usr file system

[Anoop Sivan]

Hi All

Need to extend /usr file system. Currently no free PV's are available, and the lvol7 (mounted as /usr) is mirrored. We have raised new lun request for the file system extension.
We wre planning to do following steps. Please suggest any change is required for the below plan.

pvcreate /dev/dsk/
vgextend /dev/vg00 /dev/dsk/
lvextend -L xxxxM /dev/vg00/lvol7
fsadm -F vxfs -b xxxxM /usr

[Matti_Kurkela]

As the LV is mirrored and there are no free extents, you'll need *two* new PVs. The default allocation policy (= strict) will not allow placing both halves of the mirrored LV onto the same PV.

So:

pvcreate /dev/rdsk/
pvcreate /dev/rdsk/
vgextend /dev/vg00 /dev/dsk/
vgextend /dev/vg00 /dev/dsk/
lvextend -L xxxxM /dev/vg00/lvol7
fsadm -F vxfs -b xxxxM /usr

MK

[James R. Ferguson]

Hi:

You can't do this assuming that the default 'strict' option is in force for preventing mirrored copies from residing on the same physical device.

Since you don't have any free extents, you will need to add *two* physical volumes to the volume group so that mirrored copies occupy separate disks. After all, to do otherwise obviates the reason to mirror --- high-availability and recovery of data when one mirror fails.

Regards!

...JRF...

[Anoop Sivan]

Thanks for the reply,

Here my only doubt is the lvol7 is mirrored, and the new lun's are 20GB. So when we extend the lvol7, whether the mirror is also establish or any additional steps is required.

[James R. Ferguson]

Hi (again):

> So when we extend the lvol7, whether the mirror is also establish or any additional steps is required.

Extending a mirrored logical volume extends the mirrored extents automatically. You also have the option (though in this case it doesn't matter) of specifying the physical volumes to use. Regardless, the allocation policies (e.g. strict) will be enforced.

Regards!

...JRF...

[SoorajCleris]

Hi,

From the information above, I understand you would not be able to extend it untill and unless you add two disks to the VG /change the allocation policy -not recommended/remove the mirror- not recommended!!!

I would suggest you to add two LUNs and follow the procedure..

Regards,
Sooraj

[Anoop Sivan]

Thanks for all your valuable reply, we are going to use below steps

#pvcreate /dev/dsk/
#pvcreate /dev/dsk/
#vgextend /dev/vg00 /dev/dsk/ /dev/dsk/
#lvextend -L /dev/vg00/lvol7
#fsadm -F vxfs -b /usr
#bdf /usr