The issue:
Corruption in /etc/vx/disk. info results in filesystem corruption.
This issue only occurs where the following conditions are met:
1) Volume Manager 5.0MP3 (with or without Rolling Patch1, 2, or 3) is installed
2) Persistent device naming is set to "on".
3)Changes were made to the LUNs presented to the host.

Symptoms:
The output of "vxprint -ht" will show the same device attached to multiple disk media names.
For example:
# vxprint -ht | grepdisk1909
dmc2t102d45    disk1909_1 auto    2048     62894976-
dmc2t102d46    disk1909_1 auto    2048     62894976-
dmc2t102d47    disk1909_1 auto    2048     62894976-
dmc2t102d55    disk1909_1 auto    2048     62894976-
dmc2t102d56    disk1909_1 auto    2048     62894976-
dmc2t102d57    disk1909_1 auto    2048     62894976-
dmc2t102d58    disk1909_1 auto    2048     62894976-
dmc2t102d59    disk1909_1 auto    2048     62894976-
dmc2t102d60    disk1909_1 auto    2048     62894976-
dmc2t102d61    disk1909_1 auto    2048     62894976-

Note the duplication of names in the second column.

Multiple sub-disk entries (even for different volumes) point to the same, single LUN, as seen below with continued output from the "vxprint -ht" command.
sd c2t102d45-01 data-01 c2t102d450       62893056 4/0 disk1909_1ENA
sd c2t102d46-01 data-01 c2t102d460       62893056 5/0 disk1909_1ENA
sd c2t102d47-01 data-01 c2t102d470       62893056 6/0 disk1909_1ENA
sd c2t102d55-01 dump-01 c2t102d550       62893056 0/0 disk1909_1ENA
sd c2t102d56-01 dump-01 c2t102d560       62893056 1/0 disk1909_1ENA
sd c2t102d57-01 dump-01 c2t102d570       62893056 2/0 disk1909_1ENA
sd c2t102d58-01 dump-01 c2t102d580       62893056 3/0 disk1909_1ENA
sd c2t102d59-01 dump-01 c2t102d590       62893056 4/0 disk1909_1ENA
sd c2t102d60-01 dump-01 c2t102d600       62893056 5/0 disk1909_1ENA
sd c2t102d61-01 dump-01 c2t102d610       62893056 6/0 disk1909_1 ENA

A review of the /etc/vx/disk.info file also indicates the mismatch of the disk media name to the disk access name.
Each line entry in /etc/vx/disk.info should be a unique LUN.

# cat disk.info | grepdisk1909_1
EMC%5FSYMMETRIX%5F000287751909%5F094D2000c0t6006048000028775190953594D344432d0 0x50801a0 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094D4000c0t6006048000028775190953594D344434d0 0x50801e0 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094D5000c0t6006048000028775190953594D344435d0 0x5080208 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094D7000c0t6006048000028775190953594D344437d0 0x50800a8 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094D6000c0t6006048000028775190953594D344436d0 0x50800e0 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094C9000c0t6006048000028775190953594D344339d0 0x5080088 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094C7000c0t6006048000028775190953594D344337d0 0x50801f0 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094C8000c0t6006048000028775190953594D344338d0 0x5080030 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094D1000c0t6006048000028775190953594D344431d0 0x5080188 0x2 disk1909_1 EMC000287751909
EMC%5FSYMMETRIX%5F000287751909%5F094D3000c0t6006048000028775190953594D344433d0 0x50801c0 0x2 disk1909_1 EMC000287751909

The mis-mapping of the disk media name results in all I/O affected by the mis-map being directed to the incorrect disk media name (s).
This results in corruption of the filesystems on the volumes which are mis-mapped.

To resolve the issue:
This issue is fixed in 5.1RP1.

The issue may be avoided on 5.0 versions by turning off persistent device naming.
For versions 5.0 and later, persistent device naming is not necessary for the proper operation of the Volume Manager product.
Turning off persistent device naming results in Volume Manager not using the /etc/disk.info as a part of VxVM transactions and will prevent the possible mis-map issue.

To change the setting, two parameters must be changed:
persistent device naming
enclosure-based naming (ebn) or operating system naming (osn)

The following command may be used to implement the change:
# vxddladm setnamingscheme=osn persistence=no

After turning off the persistent name setting, the setting for ebn/osn may be returned to its original state, if desired:
# vxddladm setnamingscheme=ebn persistence=no