unused lv format unrecognized

[Dave Chamberlin]

I have an lv, lvol8 that is 200MB large and mirrored and not mounted. SAM shows this volume as "unused". An lvdisplay show the extents are current. When I try to mount it, I get the error "unrecognized file system". The other lvs I have on those disks are ok. I thought that the newfs command is used on the device level to create a file system. So how is just this lv in an unrecognized format? I really just want to use the space to make my /opt and /var larger. Can I just do an lvreduce on this lv, and then use lvextend, etc where I want the space? Thanks.

[Elizabeth_2]

Hi Dave!

A logical volume that DOES NOT contain a file system cannot be mounted. If the mount command is used to attempt to mount a logical volume that doesn't contain a file system, an error message of: unrecognized file system will be given.

Once a file system is created, then the logical volume could be successfully mounted.

Elizabeth

[Rainer_1 · Accepted solution]

if your mount says "unrecognized file system" then there is NO filesystem on it.
To create a filesystem use

newfs -F vxfs /dev/vg00/rlvol8 # for vxfs fs
(newfs -F hfs /dev/vg00/rlvol8 # for hfs)

But i noticed that you want to increase your /opt and /var filesystem.
For this issue you don't have to create a new lvol. Instead extending the existing lvols is required.
So remove the unused lvol8

lvremove /dev/vg00/lvol8

and extend /opt (ie: lvol6) and /var (ie: lvol7)

lvextend -L /dev/vg00/lvol6
lvextend -L /dev/vg00/lvol7

after that you have to extend the filesystem.
For this job you have to umount first. As you want to extend /opt and /var you have to boot into single user mode.
Then do

extendfs /dev/vg00/rlvol6
extendfs /dev/vg00/rlvol7

and boot back to mutil user mode.

[CHRIS_ANORUO]

Remove the unused lvol8 with lvremove /dev/vg00/lvol8
Backup all the data from the filesystem involved. Note the logical volume numbers.
Reboot to single user mode(to umount the filesystems)
Extend /var and /opt:
lvextend -L XXX /dev/vg00/lvoln(n for /var or /opt).
extendfs -F vxfs /dev/vg00/rlvoln
Mount the filesystems and restore the files
Then, Reboot the system

[Dave Chamberlin]

Thanks for the info - I did not know that newfs could be used on a LV - the man pages for newfs only show examples like: newfs -F hfs /dev/rdsk/c1t1d0, so I assumed that this was done on my disk when it was installed, hence any LVs on that disk should have a file system.