Take a look at this thread for more information:

Re: get disk partitions

Sample execution:

[vi-admin@vima ~]$ ./queryDiskParition.pl --server <esx_erver> --device /dev/cciss/c0d0
partition: 1
type: linuxNative
startSector: 63
endSector: 514079
isLogical: NO
size: 250.98 MB

partition: 2
type: linuxNative
startSector: 514080
endSector: 17285939
isLogical: NO
size: 8.00 GB

partition: 3
type: linuxSwap
startSector: 17285940
endSector: 20643524
isLogical: NO
size: 1.60 GB

partition: 4
type: extended
startSector: 20643525
endSector: 143299799
isLogical: NO
size: 58.49 GB

partition: 5
type: vmfs
startSector: 20643588
endSector: 126319094
isLogical: YES
size: 50.39 GB

partition: 6
type: linuxNative
startSector: 126319158
endSector: 134705024
isLogical: YES
size: 4.00 GB

partition: 7
type: linuxNative
startSector: 134705088
endSector: 138897989
isLogical: YES
size: 2.00 GB

partition: 8
type: linuxNative
startSector: 138898053
endSector: 143090954
isLogical: YES
size: 2.00 GB

partition: 9
type: vmkDiagnostic
startSector: 143091018
endSector: 143299799
isLogical: YES
size: 101.94 MB

Total size: 68.33 GB