Steve,
Are you using the latest update release of Solaris 10 ?
When you are doing the copy, did you check with prstat -amL to see if it
is saturating on any CPU?
If it is saturating on a CPU then atleast it will narrow down that you
need to improve the CPU utilization of the copy process.
Brendan Greg's "hotuser" script which uses DTrace and Pearl post
processing will help you to figure out which functions is causing the
high CPU utilization and then maybe somebody from the PostgreSQL team
can figure out what's happening that is causing the slow copy.
If none of the cores show up as near 100% then the next step is to
figure out if any disk is 100% utilized via iostat -xczmP .
With this information it might help to figure out the next steps in your
case.
Regards,
Jignesh
Steve wrote:
Hello there;
I've got an application that has to copy an existing database to a new
database on the same machine.
I used to do this with a pg_dump command piped to psql to perform the
copy; however the database is 18 gigs large on disk and this takes a
LONG time to do.
So I read up, found some things in this list's archives, and learned
that I can use createdb --template=old_database_name to do the copy in
a much faster way since people are not accessing the database while
this copy happens.
The problem is, it's still too slow. My question is, is there any way
I can use 'cp' or something similar to copy the data, and THEN after
that's done modify the database system files/system tables to
recognize the copied database?
For what it's worth, I've got fsync turned off, and I've read every
tuning thing out there and my settings there are probably pretty
good. It's a Solaris 10 machine (V440, 2 processor, 4 Ultra320
drives, 8 gig ram) and here's some stats:
shared_buffers = 300000
work_mem = 102400
maintenance_work_mem = 1024000
bgwriter_lru_maxpages=0
bgwriter_lru_percent=0
fsync = off
wal_buffers = 128
checkpoint_segments = 64
Thank you!
Steve Conley
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