OS RHEL 5.5 - Veritas Storage Foundation 5.1 SP1 RP2 (VCS) .The big quetion is about the two dmp.Can they coexist together or there are some issue on path failover?
Checked couple of documents like HCL & DMP guides however nothing useful found
nothing mentioned for RDAC + DMP co existence on Linux ... there are comments for use of RDAC on AIX ..
If something is not mentioned then I would take it as not tested or not supported ... can not predict the behavior ...
Looking at guide, here is what mentioned for AIX only in
For AIX Platform, the IBM DS3xxx/DS4xxx/DS5xxx arrays require the use of RDAC driver
as a multipathing driver in conjunction with the Veritas products.
Furthermore, the use of multiple primary paths is not supported on these DS3xxx/DS4xxx/DS5xxx arrays with AIX platform.
The DMP functionality of the DS3xxx/DS4xxx/DS5xxx arrays have the following additional
requirements for use with the supported Veritas products.
For procedural details, see “Storage Manager and Host Support Guide” at http://www-947.ibm.com/support/entry/portal/docdisplay?Indocid=MIGR-5075652
Your best bet is to contact Symantec Support as even if someone from Symantec answers this question on this forum and says it is supported you will have a hard time logging a support call, because one of the first things Support check is the HCL and if hardware is not listed, they will ask you to comply with HCL, so you will need a Support Exception for this to be supported of for the HCL to be updated. The current documentaion is not very clear, so it may be supported - in particular, for third party multipathing with VCS wth LVM (not VxVM), link http://www.symantec.com/business/support/index?page=content&id=TECH146404 specifically for RHEL says
If SAN LUN multipathing is a requirement for the VCS cluster, the recommedation is to migrate LVM data to VxVM 5.1 with its bundled DMP multipathing or use other VxVM compatible third party (TPD) multipathing software (e.g. EMC PowerPath).
So this implies EMC PowerPath is supported with VCS and LVM, but this is NOT listed by the 5.1 HCL and this only lists VCS and LVM with third party multipathing for AIX:
The VCS LVM agent supports the EMC PowerPath third-party driver on EMC's Symmetrix 8000 and DMX series arrays.The VCS LVM agent supports the IBM MPIO third-party driver on IBM's DS8000 arrays.The VCS LVM agent supports the IBM SDD third-party driver on IBM's ESS750/800 and DS8000 arrays.The VCS LVM agent supports the HITACHI HDLM third-party driver on Hitachi USP/NSC/USPV/USPVM, 9900V series arrays.
The settings shown for arrays reflect those used in Symantec’s testing, and are not necessarily the only supported settings.