Scenario: A developer needs to know whether the file storage system is local or pointing to a LUN. For instance, the file systems he/she works on is /u02. Does it map to a local storage or SAN?
Steps:
1. Issue a mount command to first list out the mounted LOGICAL and/or PHYSICAL file systems and their mount points.
Example:
$ mount
node mounted mounted over vfs date options
-------- --------------- --------------- ------ ------------ ---------------
/dev/hd4 / jfs2 28 Oct 03:11 rw,log=/dev/hd8
/dev/hd2 /usr jfs2 28 Oct 03:11 rw,log=/dev/hd8
/dev/hd9var /var jfs2 28 Oct 03:11 rw,log=/dev/hd8
/dev/hd3 /tmp jfs2 28 Oct 03:11 rw,log=/dev/hd8
/dev/hd1 /home jfs2 28 Oct 03:16 rw,log=/dev/hd8
/dev/hd11admin /admin jfs2 28 Oct 03:16 rw,log=/dev/hd8
/proc /proc procfs 28 Oct 03:16 rw
/dev/hd10opt /opt jfs2 28 Oct 03:16 rw,log=/dev/hd8
/dev/livedump /var/adm/ras/livedump jfs2 28 Oct 03:16 rw,log=/dev/hd8
/dev/fslv00 /audit jfs2 28 Oct 03:16 rw,log=/dev/hd8
/dev/u01lv /u01 jfs2 28 Oct 03:16 rw,log=/dev/hd8
/dev/u03lv /u03 jfs2 28 Oct 03:16 rw,cio,log=INLINE
/dev/u06lv /u06 jfs2 28 Oct 03:16 rw,cio,log=INLINE
/dev/u02lv /u02 jfs2 28 Oct 03:16 rw,cio,log=INLINE
/dev/u07lv /u07 jfs2 28 Oct 03:16 rw,cio,log=INLINE
tggfilesvr1 /D/TempNFS /mnt/tggfilesvr1 nfs3 28 Oct 03:16 rw,bg,hard,intr,sec=sys
Clearly, /dev/hd* are the physical drives. However, u**lv seem to be logical volumes created by grouping one or more physical drives together.
2. Issue a command lslv to list the details of a logical volume.
Example:
$ lslv -l u01lv
u01lv:/u01
PV COPIES IN BAND DISTRIBUTION
hdisk7 184:000:000 34% 000:064:000:093:027
hdisk0 184:000:000 34% 000:064:000:101:019
$ lslv -l u02lv
u02lv:/u02
PV COPIES IN BAND DISTRIBUTION
hdisk2 1450:000:000 25% 150:375:200:375:350
Clearly, LV u01lv is made of hdisk7 and hdisk0 whereas u02lv (mounted on u02) is mapped to hdisk2.
3. Now we know that u02 file in question is pointing to physical drive hdisk2. In order to make sure whether it is in fact pointing to SAN, issue following command:
$ lsattr -El hdisk2 |grep lun_id
lun_id 0x2000000000000 Logical Unit Number ID False
If there is no SAN involved there will not be any output. Else, there will be one as above.
Thanks for reading.
