Re: Oracle IO tuning tips/practices on Windows

Answers embedded:
"NetComrade" <netcomradeNSPAM@xxxxxxxxxxxxxxxx> wrote in message
news:nom4u1hajl4hc9579kcj60bfhhv1iv7m6q@xxxxxxxxxx
On 1 Feb 2006 17:12:30 -0800, bdbafh@xxxxxxxxx wrote:

The array is Dell PowerVault V220. There is a 128M cache.. more
details below

It would be better with 256M or even more

db_block_size
8K and 16K
number of SCSI RAID controllers and channels
1 and 1 (I think)
number of hard drives
12
RAID configuration (e.g. 8 disk RAID 10)
12 disk RAID10 (6disk stripe)
stripe size (e.g. 256 KB stripe)
64K

Better would be 256KB or even 1MB
(Your drives are doing seek operations most of the time!)

An 8 drive RAID 10 volume of stripe size 256 KB would be a good start.
with an 8192 byte db block size, a db_file_multiblock_read_count = 32
would read a full stripe. That doesn't help much with single block io,
unless the blocks are prefetched and accessed before they are aged out.

Their db_file_multiblock_read_count is set to 8. Which is fine for an

But 32 would be better after larger (256MK) stripe set

Jack


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Relevant Pages

  • [PATCH 01/19] raid5: raid5_do_soft_block_ops
    ... operations into a single routine. ... The stripe operations are: ... plus raid5d if it is handling it, plus one for each active request ... * -copying data between the stripe cache and user application buffers ...
    (Linux-Kernel)
  • [PATCH 05/12] md: workqueue for raid5 operations
    ... Each raid5 device gets its own queue, and each stripe has its own ... * Parity calculations are done inside the stripe lock ... /* unfortunately we need two cache names as we temporarily have ...
    (Linux-Kernel)
  • Re: Stripe sizes with gstripe
    ... you could have a 512 byte stripe size. ... single block, but gstripe reads the entire stripe to fulfill the request. ...
    (freebsd-questions)
  • Re: RAID and NTFS Question
    ... It is Adaptec hardware, stripe size 8k, 3 stripes, rebuild rate 170, ... cache size 64mb. ... WriteThru, Read Ahead, Cached I/O. ...
    (microsoft.public.win2000.active_directory)