can't mount /usr in single user mode

[hi_5]

Error message when tried to mount /usr in single user mode

/sbin/fs/vxfs/mount -r /dev/vg00/lvol4 /usr
vxfs mount: Cannot deduce character device name for /dev/vg00/lvol4

[Martin Johnson · Accepted solution]

Check to see if /dev/vg00/rlvol4 exists. If not, you will need to create it.

HTH
Marty

[hi_5]

i have rlvol4b not lvol4....
how can i recreate the rlvol#?

[Jeff Schussele]

Hi,

I agree with Marty - verify that /usr is indeed lvol4. Check your /etc/fstab.
If you're truly in single-user mode then run mount -a to mount everything & have the system pick up the info from /etc/fstab
Also, why are you mounting it read-only?

HTH,
Jeff

[Jeff Schussele]

To create the lvol4b entry do the following:

1) Note the major # (should be 64) & minor # of rlvol4b - should be like 0x000004 or so
2) Run the mknod command as follows
mknod lvol4b b 64 0x000004 # or whatever the minor number of rlvol4b is.

But seeing that rlvol4b entry leads me to believe somebody typo'd the original mknod command & didn't space between the lvol name & the device type "b" or block device.
That might explain *why* there's no block device for the lvol4 entry.
Again, what does /etc/fstab have for the /usr entry?
And has this system ever been successfully booted such that /usr comes up mounted?

HTH,
Jeff

[James R. Ferguson]

Hi:

The 'b' suffix suggests that you did a 'lvsplit' (perhaps to do a backup). If you are truly missing '/dev/vg00/lvol4' and have only 'dev/vg00/lvol4b' then I would ask if you in fact did an 'lvsplit' followed by an 'lvmerge' with the destination and source paths reversed? (See the man pages for 'lvmerge').

Regards!

...JRF...

[Jeff Schussele]

Good catch JRF.
Never thought about an lvsplit gone bad.
Learn something new every day.....

Thx,
Jeff