Re: Storage management?????

On Wed, 3 Oct 2001, Chris Pesko wrote:

> Thank you for responding and here is a follow up question regarding your
> scalability answer.  Is the database size limited to the size of the one
> disk it rides on.  Or does the directory volume need to be configured to
> span multiple disks to get some scalability?
>
---------------->8 SNIP 8<------------------
Chris,

    If you are asking if it is possible for a database to grow from
one filesystem to another, the answer is currently "NO".  However, as was
already pointed out, you can put the files anywhere and use symbolic links
to the files.  I have distributed my largest database across 5 drives on
2 separate SCSI busses at this point.  I have placed index files on 2
disks, and table files on 2 others, and the WAL files on another (7.1.2
unpatched).  The goal has been to reduce disk latency during updates to
the tables for large multi-table transactions, and it has worked quite
nicely.  The only real problem has been that I needed to write a script
that warns me whenever a table grows beyond 1GB.  The new file
(ie. 64587393.1) is created in $PGDATA and I then move it to whichever
drive I have the master file (ie. 65487393) on.  I could automate the
whole thing using the perl script, but this would mean having the script
automagically do a 'pg_ctl stop', move the file to a pre-defined
drive, create the link, 'pg_ctl start'.  Since I do this manually during
low system usage times, and I don't trust the script to work 100% of the
time, I just do it by hand.

- brian

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