Unsplitting mirrored disks

[Simon R Wootton]

I have a system with multiple mirrored disks (eg /dev/vg09/lvol1). I would like to lose this mirror and make the filesystem (eg. /user16) twice it's mirrored size. How do I do this ?

P.S. This thread has been moved from  Disk to HP-UX > sysadmin. -HP Forum Moderator

[Vincent Farrugia]

Hello,

You need to execute the following command for all logical volumes you have:

lvreduce -m 0 /dev/vgname/lvname

where vgname is the name of the vg and lv name is the name of the logical volume.

You don't need to extend your harddisks again since they are already in the lvmtab.

HTH,
Vince

[Martin Johnson]

Do "lvreduce -m 0 /dev/vg09/lvol1" repeat the command for any additional lvol's you want to unmirror. Do a "lvextend -L newsize /dev/vgxx/lvolx" on the logical volume that contains the /user16 file system. Finally do an "extendfs" to extend the /user16 file system.

You can also do this with SAM.

HTH
Marty

[S.K. Chan · Accepted solution]

This depends on whether you have OnlineJFS installed or not ..

Without OnlineJFS
=================
# umount /user16
# lvreduce -m 0 /dev/vg09/lvol1
# vgdisplay vg09
==> Take note of how many "Free PE" is now available for the extension (lets say its 400 free PEs which means you got additional 400x4=1600MB space assuming your PE size stays default at 4MB).
# lvextend -L 3200 /dev/vg09/lvol1
==> Extending your LV to the "new" size 3.2GB (just an example here)
# extendfs -F vxfs /dev/vg09/rlvol1
==> Assuming you're using "vxfs", if HFS just replace that with "hfs".
# mount -a
# bdf
==> Check the FS size.

With OnlineJFS (can be done on the fly)
=======================================
# lvreduce -m 0 /dev/vg09/lvol1
# lvextend -L 3200 /dev/vg09/lvol1
# fsadm -b 3276800 /user16
# bdf
==> Check the FS size.
==> 3200*1024=3276800

[George Petrides_1]

When you say 'multiple mirrored disks' you mean one mirror disk or two? If two, then follow the instructions of the other fellas, however, change your command lvreduce -m 1 ..... to go from two mirrored disks to 1. Just in case...
George