DM-MPIO has a big advantage in that it is free with the OS. PowerPath is not free, will require you to purchase a license, although if you have PowerPath on all your other servers, you may have already paid for that license as part of a bundle. The main advantage of PowerPath is that it performs both load-balancing and path failover. DM-MPIO will only failover paths if they die. No IO load balancing across paths.
Regarding the question about support for RHEL4 on PP5.1SP1, looking at the release notes the following is mentioned:
This PowerPath 5.1 SP1 release is a separate package from PowerPath 5.1.0 and contains different functionalities. The additional functionalities, support, and fixes in PowerPath 5.1.0 are exclusive to that release and may not necessarily apply to PowerPath 5.1 SP1. This section includes subsections for each package: one for new features and changes for PowerPath 5.1 SP1 for Linux, and one for features and changes for PowerPath 5.1.0. Refer to the appropriate section for your installation.
To me that reads, PP5.1SP1 was specifically written to include support for new kernels and fix bugs found only in RHEL5/SuSE9&10. PowerPath 5.1.0 supports RHEL4.
Update to DM-Multipath packages are available like other other Linux pacakges and hence easy to manage. Power is a third party module for the Linux and we have to take care of that.. like what version to upgrade to and its not a free product.
Also PP need to be reinstalled each time we do a kernel upgrade.
gauge1
17 Posts
0
June 15th, 2008 19:00
Conor
341 Posts
0
June 15th, 2008 23:00
PowerPath is not free, will require you to purchase a license, although if you have PowerPath on all your other servers, you may have already paid for that license as part of a bundle.
The main advantage of PowerPath is that it performs both load-balancing and path failover. DM-MPIO will only failover paths if they die. No IO load balancing across paths.
Regarding the question about support for RHEL4 on PP5.1SP1, looking at the release notes the following is mentioned:
This PowerPath 5.1 SP1 release is a separate package from PowerPath
5.1.0 and contains different functionalities. The additional
functionalities, support, and fixes in PowerPath 5.1.0 are exclusive to
that release and may not necessarily apply to PowerPath 5.1 SP1.
This section includes subsections for each package: one for new
features and changes for PowerPath 5.1 SP1 for Linux, and one for
features and changes for PowerPath 5.1.0. Refer to the appropriate
section for your installation.
To me that reads, PP5.1SP1 was specifically written to include support for new kernels and fix bugs found only in RHEL5/SuSE9&10.
PowerPath 5.1.0 supports RHEL4.
SKT2
2 Intern
•
1.3K Posts
0
June 19th, 2008 11:00
Also PP need to be reinstalled each time we do a kernel upgrade.