Re: SAN performance - Mailing list pgsql-performance

From Anjan Dave
Subject Re: SAN performance
Date
Msg-id 4BAFBB6B9CC46F41B2AD7D9F4BBAF78509853D@vt-pe2550-001.vantage.vantage.com
Whole thread Raw
In response to SAN performance  ("Anjan Dave" <adave@vantage.com>)
Responses Re: SAN performance
List pgsql-performance
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
sizeof 128 sectors default.
 
 
Thanks,
Anjan

    -----Original Message----- 
    From: Mr Pink [mailto:mr_pink_is_the_only_pro@yahoo.com] 
    Sent: Thu 9/23/2004 11:39 AM 
    To: Anjan Dave; pgsql-performance@postgresql.org 
    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 <adave@vantage.com> 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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