Oracle RAC and VxVM vs LVM

[Rick Garland]

Hi all:

Getting some info together about our Oracle RAC environment.

Question of the day is, what are pros and cons of using Veritas File System vs. LVM in using the raw filesystems for RAC?

[Luk Vandenbussche]

Hi Rick,

First answer is very simple

Veritas is much easier to handle and to manage the filesystems

[A. Clay Stephenson · Accepted solution]

If you are going to use a Veritas Clustered Filesystem then you must be running MC/SG with RAC extensions. This also requires that a dedicated network be present to handle the buffer cache consistency across boxes. I would say that one of the main advantages of CFS over raw devices (your use of "raw filesystems" is self-contradictory) is that the standard utilities can be used to copy, rename, and backup files.

[Julio Yamawaki]

Rick:

There is a new version of SG RAC Extension to be issued wich will include VxVM.
I think if you use shared LVM you will have a better performance in acessing data, in the other side, every time you need to increase datafile size (and, of course, logical volume) you need to stop services, because you cannot do this operation with volume group activated in shared mode.
If you use VxVM, you can do online extension without any problem, but performance is not so good as in SLVM.
This performance problem can be a issue if you use a database in billing or some other application that needs full performance of disk (and you cannot upgrade this disks to a better physical performance), in any other case, use VxVM.

Regards,

[Rick Garland]

Thanks for the info