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FC60 Configuration

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FC60 Configuration

I have an N4000/4 CPU system linked by two Fibre Channels to an FC60. The FC60 has three SC10's installed. These are configured in full bus mode to allow a further SC10 to be installed in the future. We run Oracle Applications which uses a version 8.0.3 Oracle database. We are having severe performance problems. Disc seems to be a key bottle-neck. We are looking at moving files around the system to even the load. I have also been advised that I should modify the FC60 'Cache Block Size' from 4K to 16K.

Present configuration:
Vendor ID = HP
Product ID = A5277A
Array ID = 015800A0B8060DDE
Array Alias = fc60
Overall State of Array = READY
Array configuration:
Cache Block Size = 4 KB / 4 KB
Cache Flush Threshold = 80 % / 80 %
Cache Flush Limit = 100 % / 100 %
Cache Size = 256MB / 256MB

How do I increase this value? Do I need to rebuild my LUN's to achieve this change? Can it be carried out with the database up and running?

Any guidance would be very gratefully received.
Thanks in advance ............ Bob

Re: FC60 Configuration


I believe the command to change the cache page size is:

#ammgr -p {4|16}

Example(here I use an alias instead):

#ammgr -p 16 fc60

You might want to review the man page for ammgr. It states that cache page size cannot be set to 16K unless the segment sizes of all existing LUN's are multiples of 16KB. You should be able to see this information from and amdsp -a output.

Best Regards,

Chris Meenan

Re: FC60 Configuration

Thanks for the information Christopher - it was very useful.

I have checked my FC60:
Disk Group 0944E000003CCECE83:
Disk Group Type = LUN
Number of LUNs = 1
LUN(s) = 7
Remaining Capacity = 0.0 MB
RAID Level = 5
Segment Size = 16 KB
1:11 2:11 3:11

All LUNs are similar to the one displayed above. I am therefore okay to set the cache size to 16Kb.

Do you know whether this can be done 'on the fly' with users on the system? Does it in any way entail a rebuild of the FC60?

Regards .......... Bob

Re: FC60 Configuration


I have to admit I don't know the answer to this one for sure.

I have performed this command during initial setup with no data involved and only lun0 existed.

I would think that you should be able to do it online. We are, after all only changing the size of the Controller Cache in the fc60 controller itself. We are changing the size of the data chunk that the controller cache uses. We are not reconfiguring our luns, or our lun segment sizes. I would think this would not require any kind of rebind.

My best guess would be that you should be able to do it online and on the fly with no problems and with no rebuilding of the array.

However, if it is an extremely important host, you may want to do a full backup and keep a copy of amdsp -a handy so that if worst comes to worst, you could rebuild.

Good Luck!