Re: Linux ready for high-volume databases?

>>>>> "GS" == Greg Stark <gsstark(at)mit(dot)edu> writes:

GS> Vivek Khera <khera(at)kcilink(dot)com> writes:

>> I run a 24x7x365 db on FreeBSD which has *never* crashed in the 3
>> years it has been in production. Only downtime was the upgrade from
>> PG 7.1 to 7.2 and once for a switchover from RAID5 to RAID10.

GS> I would be interested to know what backup strategy you use for
GS> this. Without online backups this means that if you had crashed
GS> you would have lost data up to the last pg_dump you took? Had you
GS> done tests to see how long it would have taken to restore from the
GS> pg_dump?

Currently it is pg_dump. Once the new server is online this week,
we'll be using eRServer to keep a 'hot spare' slave ready for quick
switchover.

Both systems use RAID10 hardware arrays for the database.

Restore from dump takes about an hour for the data, and then the rest
of eternity (something like 18 hours last time I did it) for index
generation.

The pg_dump process takes about 52 minutes across the network.

GS> Oh, it's a really small database. That helps a lot with the backup
GS> problems of 24x7 operation. Still I would be interested.

Well, perhaps, but it is big enough and pounded on enough
(read/insert/update very often) that it saturates the disk. I have
memory to spare according to the system stats.

I personally *really* wonder how people run DBs that are much larger
and have high rate of read/insert/update across large tables with RI
checks and all that normal good stuff. The tuning recommendations I
have been through are insufficent to really help for my load. Perhaps
my current server hardware just isn't up to it.

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Vivek Khera, Ph.D. Khera Communications, Inc.
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