Adding a Plex to a Logical Volume

Adding a Plex to a Logical Volume

If you have purchased the Disk Plexing Option software option and have installed a NetLS license for it (remember that its NetLS license is installed in a nonstandard location, /etc/nodelock), you can add a plex to an existing subvolume for improved reliability in case of disk failures. The procedure to add a plex to a subvolume is described below. To add more than one plex to a subvolume or to add a plex to each of the subvolumes in a volume, repeat the procedure as necessary.

If the plex that you want to add to the subvolume doesn't exist yet, create it with xlv_make. For example, to create a plex called plex1 to add to the data subvolume of a volume called root_vol, give these commands:
# xlv_make
xlv_make> plex plex1
plex1
xlv_make> ve /dev/dsk/dks0d3s7
plex1.0
xlv_make> end
Object specification completed
xlv_make> exit
Newly created objects will be written to disk.
Is this what you want?(yes) yes
Invoking xlv_assemble
Use the xlv_mgr command to add the plex to the volume. For example, to add the standalone plex plex1 to root_vol, use this procedure:
# xlv_mgr
xlv_mgr> attach plex plex1 root_vol.data
xlv_mgr automatically initiates a plex revive operation to copy the contents of the original plex, root_vol.data.0, to the newly added plex.
You can confirm that root_vol now has two plexes by displaying the object hierarchy:
xlv_mgr> show object root_vol
VOL root_vol (complete)
VE root_vol.data.0.0 [active]
start=0, end=988091, (cat)grp_size=1
/dev/dsk/dks0d2s7 (988092 blks)
VE root_vol.data.1.0 [empty]
start=0, end=988091, (cat)grp_size=1
/dev/dsk/dks0d3s7 (988092 blks)
The newly added plex, root_vol.data.1, is initially in the "empty" state. This is because it is newly created.
Exit xlv_mgr:
xlv_mgr> quit

The plex revive completes and the new plex switches to "active" state automatically, but if you want to check its progress and verify that the plex has become active, follow this procedure:

List the XLV daemons running, for example:

# ps -ef | grep xlv
    root    27     1  0 10:49:27 ?        0:00 /sbin/xlv_plexd -m 4
    root    35     1  0 10:49:28 ?        0:00 /sbin/xlv_labd
    root    31     1  0 10:49:27 ?        0:00 xlvd
    root   407    27  1 11:01:01 ?        0:00 xlv_plexd -v 2 -n root_vol.data
-d 50331648 -b 128 -w 0 0 1992629
    root   410   397  2 11:01:11 pts/0    0:00 grep xlv

One instance of the xlv_plexd daemon is currently reviving root_vol.data. This daemon exits when the plex has been fully revived.

Later, check the XLV daemons again, for example:

# ps -ef | grep xlv
    root    27     1  0 10:49:27 ?        0:00 /sbin/xlv_plexd -m 4
    root    35     1  0 10:49:28 ?        0:00 /sbin/xlv_labd
    root    31     1  0 10:49:27 ?        0:03 xlvd
    root   459   397  2 11:21:10 pts/0    0:00 grep xlv

The instance of xlv_plexd that was reviving root_vol.data is no longer running; it has completed the plex revive.

Check the state of the plex using xlv_mgr:
# xlv_mgr
xlv_mgr> show object root_vol
VOL root_vol (complete)
VE root_vol.data.0.0 [active]
start=0, end=988091, (cat)grp_size=1
/dev/dsk/dks0d2s7 (988092 blks)
VE root_vol.data.1.0 [active]
start=0, end=988091, (cat)grp_size=1
/dev/dsk/dks0d2s0 (988092 blks)
xlv_mgr> quit
Both plexes are now in the "active" state.