We are planning to setup a 10gR2 RAC and storage on ASM. We use Sun StorEdge SAN.
The installation and configuration manual says to configure ASM diskgroups with raw devices (preferably raw disk not volumes).
I dont really know if its possible to present raw disks to the Solaris O.S.
Can anyone share their experience with storage for ASM diskgroups (for Oracle datafiles and recovery files).
Are you using raw SAN Volumes or raw disks? If its raw volumes whats the RAID level you are using? or if its raw disks, how have you presented raw disks to the O.S from the SAN?
My DBA asked for RAW Volumes (Raid 5)
You just assign the volume of the required size to the system. Check using format command that the volume is there or in our case use the emcpower utitlity
Partition the raw device. START FROM CYLINDER 1 NOT 0. Leave cylinder 0.
This is partially true. Setup Slice 0 with 100MB at the beginning of the drive. Then setup another slice using the rest of the drive. Give the DBAs access to the "other" slice, not slice 0.
Can you please give me a little more details of how many RAW volumes you created for ASM? Did you create all of them as RAID 5?
Did the DBA also ask you for RAW devices for OCR and Voting disks? It needs just 256MB each but on separate disks (preferably). How did you create those RAW devices?
All of them were created on RAID5. However RAW data devices were distributed across two Raid Groups for better IO performance. Yes OCR and Voting disks were also raw devices.
All Raw Devices were assign from SAN (FC disks). This is a test environment, so performance is not a big issue.