My best guess right now is that recompiling pg with a 4kb datablock size, and using 4kb filesystem blocks with an 8 sector (4kb) element size is probably the way to go for an active database.
Contact me off-list if you want a copy of the EMC CLARiiON "Best Practices for Fiber Channel Storage" white paper. Haven't read it since I only got my copy this morning, but... looks promising.
Drew
Anjan Dave wrote:
I believe 1/0 or 1+0 is aka RAID-10. CX300 doesn't support 0+1.
So far i am aware of two things, the cache page size is 8KB (can be increased or decreased), and the stripe element size of 128 sectors default.
Thanks,
Anjan
-----Original Message----- From: Mr Pink [mailto:[EMAIL PROTECTED] Sent: Thu 9/23/2004 11:39 AM To: Anjan Dave; [EMAIL PROTECTED] Cc: Subject: Re: [PERFORM] SAN performance
Hi,
I expect you mean RAID 1/0 or 1+0 since the CX300 didn't support RAID 10 last time I looked.
Whether you are using a SAN or not, you should consider putting the WAL files (pg_xlog folder) on seperate diskes from the DB. Since the log files are mostly written to, not read from you could just use RAID 1.
It's a pity pg doesn't have a way to use a cluster of servers to get the most out of your expensive SAN.
I read a comment earlier about setting block sizes to 8k to math pg's block size. Seems to make sense, you should check it out.
Have fun, Mr Pink
--- Anjan Dave <[EMAIL PROTECTED]> wrote:
> Hello, > > > > I'll be moving a DB from internal RAID-10 SCSI storage to an EMC CX300 > FC RAID-10 LUN, bound to the host. I've setup a test host machine and a > test LUN. The /var/lib/pgsql/data folder is sym-linked to a partition on > the LUN. > > > > Other than the shared_buffers, effective cache size, and sort memory, I > am not sure if I need to change any other parameters in the > postgresql.conf file for getting maximum performance from the EMC box. > > > > Is there a general guideline for setting up postgres database and the > tunable parameters on a SAN, especially for EMC? > > > > Appreciate any help, > > > > Thanks, > Anjan > >
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