2009-06-24 12:44 PM
We are running a RHEL 5.2 VM on VMware as an Oracle 10g database server. Our data stores are connected via iSCSI, and I have a few questions on how to best utilize deduplication.
What are the best practices when running Oracle ASM on a VM using iSCSI LUN's? We want to fully take advantage of the space savings of dedupe on the volume by not using space reservations on the luns we are using for the ASM disks. Should our storage be VMDK's? Also, what are the best practices for LUN size in this situation?
2009-06-26 01:00 PM
The team is working on a response to your questions and will post a reply shortly. Thanks for the post!
2009-06-26 01:15 PM
I don't believe we have any best practices specific to ORACLE ASM on Vmware and iSCSI.
I would generally recommend RDMs in combination with ASM to have more flexibility in terms of move data between system types and I don't see the advantages that VMFS would provide you in this environment. RDM's do have the "extra" management overhead of needing to map multiple LUNs.
As for the sizeof the LUNs, it depends on the size of the database. For max performance I'd generally try to some reasonable small number of LUNs. From the NetApp point of view the number of LUNs doesn't really affect performance but that's not true will all OSs so I generally recommend multiple LUNs (4-8) for an application since it still realtively easy to manage but still within the sweet spot of where most configuration are running.
2009-06-26 01:42 PM
Thanks for your responses. I am basically trying to determine if adding the ASM disks to the VM as iSCSI LUN's is a good idea when trying to maximize a thinly provisioned volume with dedupe turned on. I have all of our ASM disks set up as vmdk's mapped to iSCSI LUN's on a flexvolume with asis enabled.
2009-06-26 02:33 PM
I realize this may be totally non-helpful....but it does seem that overall Oracle is most common either on NFS or FC.
In particular Oracle themselves run a lot of their own hosted systems on NFS IIRC.