block device for volume missing, character device in use

[Carsten Hennig]

Hi all,

I found a volume, which currently is in use by sybase (using the character device), but is not recognized by LVM. For unknown reasons the block device for that volume is missing in /dev/vgXX. What should or could I do now to make LVM recognize the volume again ? Is it safe to use mknod ? Should I stop sybase before doing anything with the volume ?

Thanks and regards,
Carsten

[Prashant Zanwar_4]

yes mknod shall be taking care of this..
What pvdisplay of the disk stating, are they alright.

Hope it helps
Thanks
Prashant

[A. Clay Stephenson]

Yes, it is safe to use mknod to create the lvol node. It's possible that some rm'ed the node. Make certain that the minor device number is unique. Hopefully the raw volume name matches the blk volume name (e.g rlvol2 -> lvol2).

[Prashant Zanwar_4]

mknod name b major minor

mknod name b 64 0x0n000x
n=uniq
x=match with charcter special device 1,2,3,4,5,6.... ,=or


Thanks
Prashant

[Carsten Hennig]

some more details:

ls -al /dev/vg05/*D03

brw-r----- 1 sybase sybase 64 0x050048 name_D03
crw-r----- 1 sybase sybase 64 0x050048 rname_D03

ls -al /dev/vg05/*D04

crw-r----- 1 sybase sybase 64 0x050025 rname_D04

[melvyn burnard · Accepted solution]

ls -al /dev/vg05/*D03

brw-r----- 1 sybase sybase 64 0x050048 name_D03
crw-r----- 1 sybase sybase 64 0x050048 rname_D03

ls -al /dev/vg05/*D04

crw-r----- 1 sybase sybase 64 0x050025 rname_D04


so do:
mknod /dev/vg05/name_D04 b 64 0x050025

then ll /dev/vg05/*D04 to check

[Carsten Hennig]

I will create that block device as soon as this box has a scheduled downtime. Production is running on it, and I want to be on the safe side... :-)

Thanks to all for your help.

Carsten