topic Re: Disabling write cache MSA1000 in Disk Enclosures

Disabling write cache MSA1000

Otong Sunaryo — Mon, 03 Apr 2006 03:10:57 GMT

Dear all,

I need to disable write cache on MSA1000 as required by application vendor.
Pls help to assist me how to disabling write cache on MSA1000.

Many thanks,
OTong

Re: Disabling write cache MSA1000

Jefferson Humber — Mon, 03 Apr 2006 03:27:52 GMT

Otong,

You could set the write cache to 0%, but have the read cache at 100%.

To do this you could use the ACU, but from the CLI it would be;

CLI> SET GLOBALS READ_CACHE=100 WRITE_CACHE=0

The read + write must equal 100.

Jeff

Re: Disabling write cache MSA1000

John Kufrovich — Mon, 03 Apr 2006 08:07:56 GMT

Otong,
You can disable cache on a per LUN basis. Check the "Array accelerator".

Re: Disabling write cache MSA1000

Otong Sunaryo — Tue, 04 Apr 2006 21:30:18 GMT

John,

If disabling cache per lun basis, it's only stated as "cache", i'm not sure what kind of cache is disabled, is it read or write cache ?

CLI> SET UNIT 1 CACHE=DISABLE
Cache for unit 1 has been disabled

what kind of cache has disabled ?

Pls help me to describe.

Thanks,
OTong

Re: Disabling write cache MSA1000

John Kufrovich — Wed, 05 Apr 2006 08:06:51 GMT

OTong,
Disabling cache on a per lun basis, you are disable read/write cache at the MSA controller.

May I ask, what application vendor or product is requiring you to disable write cache.

Re: Disabling write cache MSA1000

Otong Sunaryo — Wed, 05 Apr 2006 21:20:55 GMT

Hi John,

Thanks for your information.

Application is MIMS (provided by Mincom- this application generally used by Minning company), and using oracle Database.

Best regards,
OTong

Re: Disabling write cache MSA1000

Jim Miksitz — Thu, 01 Jun 2006 15:01:30 GMT

I too am being asked to disable write cache by Oracle. I have two Array's, first array has 1 logical unit and second has about 8 logical units. I see the option to set write to 0 and Read to 100. When I click OK to save the settings, a message appears about deleting logical units. Makes me nervous. If I make this change, it will not erase my logical drives will it ? If I'm reading it correctly, it will not, but I just want to verify with someone.

Thanks.