Re: RAC OCR/Voting Size

  • From: Sanjay Mishra <smishra_97@xxxxxxxxx>
  • To: Matthew Zito <mzito@xxxxxxxxxxx>, oraclelist@xxxxxxxxxxxxx, oracle-l@xxxxxxxxxxxxx
  • Date: Wed, 3 Jun 2009 15:32:45 -0700 (PDT)

Thanks Matt




________________________________
From: Matthew Zito <mzito@xxxxxxxxxxx>
To: Sanjay Mishra <smishra_97@xxxxxxxxx>; oraclelist@xxxxxxxxxxxxx; 
oracle-l@xxxxxxxxxxxxx
Sent: Wednesday, June 3, 2009 6:25:31 PM
Subject: RE: RAC OCR/Voting Size



Yes, I would take three luns, make small partitions on two of them for OCR, and 
on all three for voting, and then use the rest of the space on the disks for 
ASM.  Now, no disk space wasted.

As far as why you can't access the devices, have your SAN admin open a case 
with EMC - there may be FA bits that need to be flipped for RAC support. 

Matt

--
Matthew Zito
Chief Scientist
GridApp Systems
P: 646-452-4090
mzito@xxxxxxxxxxx
http://www.gridapp.com



-----Original Message-----
From: Sanjay Mishra [mailto:smishra_97@xxxxxxxxx]
Sent: Wed 6/3/2009 6:24 PM
To: Matthew Zito; oraclelist@xxxxxxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: Re: RAC OCR/Voting Size

Matt

These are completely new EMC SAN but SAN admin says that all space is allocated 
and cannot be changed. So if I have to redundancy at Cluster level is it 5 Lun 
and so wastes of 100's of gigabytes waste.

ANother question I am working on this AIX server and getting the issue in 
sharing this LUN among three Nodes. I checked that LUN assigned are having PVID 
none and no_reserve=no and permission are correct. SAN people also says that 
permission are correct as per other RAC environment. Cluster start is giving 
error

OCR initialization failed accessing OCR device: PROC-26: Error while accessing 
the physical storage Operating System error [Device busy] [16]

So only One node is coming up and if i stopped that node, then Cluster is 
coming on Second Node.

Is there any document that can tell as what setting are required to be checked 
on EMC side for OCR Luns

Sanjay

________________________________

From: Matthew Zito <mzito@xxxxxxxxxxx>
To: oraclelist@xxxxxxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Sent: Wednesday, June 3, 2009 5:41:32 PM
Subject: RE: RAC OCR/Voting Size



So, there are storage arrays where once a fixed volume size is defined, it is 
extremely difficult/expensive/risky to modify it, or provide alternately sized 
devices.  Older IBM and EMC arrays had this limitation - hearkens back to the 
mainframe days, actually.



If this is a linux system, you could put an OCFS2 filesystem on both of the 
devices, and then keep extra control files, etc. there.



Matt



________________________________

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Randy Johnson
Sent: Wednesday, June 03, 2009 3:37 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: RE: RAC OCR/Voting Size



Or you could just use 1 partition from each of several LUNs for your OCR & 
Voting. Use the rest of the space on each LUN for something else like ASM 
volumes.



By the way I find it hard to believe your storage admin cannot give you less 
than 75G LUN's. It is probably more "rather not" than "cannot".



                -Randy



From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Mark W. Farnham
Sent: Wednesday, June 03, 2009 3:46 AM
To: cicciuxdba@xxxxxxxxx; smishra_97@xxxxxxxxx
Cc: oracle-l@xxxxxxxxxxxxx
Subject: RE: RAC OCR/Voting Size



While that indeed should work, it has all the same use profile problems of 
putting all your control file copies on the same LUN.



My advice would be to "waste" the excess space on each LUN. Further, the LUNs 
thus "wasted" should ideally be composed of media using disjoint components all 
the way down to the physical media.



This may be a case where SSD could usefully be worked into the storage matrix, 
since the waste savings might well pay for the required amount of SSD.



Regards,



mwf



________________________________

From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On 
Behalf Of Guillermo Alan Bort
Sent: Tuesday, June 02, 2009 10:41 PM
To: smishra_97@xxxxxxxxx
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: RAC OCR/Voting Size



You can have a single LUN and have separate partitions within that LUN for 
OCR/Voting, and leave the rest as ASM disks.

hth
Alan Bort
Oracle Certified Professional



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