Sunday, December 30, 2012

Renaming disk devices


Getting disk devices named the same way on, for example, 2 nodes of a PowerHA cluster, can be really difficult. For us humans though, it's very useful to have the disks named the same way on all nodes, so we can recognize the disks a lot faster, and don't have to worry about picking the wrong disk.

The way to get around this usually involved either creating dummy disk devices or running configuration manager on a specific adapter, like: cfgmgr -vl fcs0. This complicated procedure is not needed any more since AIX 7.1 and AIX 6.1 TL6, because a new command has been made available, called rendev, which is very easy to use for renaming devices:

# lspv
hdisk0  00c8b12ce3c7d496  rootvg  active
hdisk1  00c8b12cf28e737b  None

# rendev -l hdisk1 -n hdisk99

# lspv
hdisk0  00c8b12ce3c7d496  rootvg  active
hdisk99 00c8b12cf28e737b  None
TOPICS: AIX, BACKUP & RESTORE, SYSTEM ADMINISTRATION↑
Lsmksysb
There's a simple command to list information about a mksysb image, called lsmksysb:

# lsmksysb -lf mksysb.image
VOLUME GROUP:      rootvg
BACKUP DATE/TIME:  Mon Jun 6 04:00:06 MST 2011
UNAME INFO:        AIX testaix1 1 6 0008CB1A4C00
BACKUP OSLEVEL:    6.1.6.0
MAINTENANCE LEVEL: 6100-06
BACKUP SIZE (MB):  49920
SHRINK SIZE (MB):  17377
VG DATA ONLY:      no

rootvg:
LV NAME    TYPE     LPs  PPs  PVs  LV STATE      MOUNT POINT
hd5        boot     1    2    2    closed/syncd  N/A
hd6        paging   32   64   2    open/syncd    N/A
hd8        jfs2log  1    2    2    open/syncd    N/A
hd4        jfs2     8    16   2    open/syncd    /
hd2        jfs2     40   80   2    open/syncd    /usr
hd9var     jfs2     40   80   2    open/syncd    /var
hd3        jfs2     40   80   2    open/syncd    /tmp
hd1        jfs2     8    16   2    open/syncd    /home
hd10opt    jfs2     8    16   2    open/syncd    /opt
dumplv1    sysdump  16   16   1    open/syncd    N/A
dumplv2    sysdump  16   16   1    open/syncd    N/A
hd11admin  jfs2     1    2    2    open/syncd    /admin