Thread: verify checksums online
i should know the answer to this... but asking anyway i think there had been some mailing list discussions years ago? the pg_checksum utility in core still can't do an online check right? looking around, i think that michael's pg_checksums_ext still seems to be available in debian repos, and it advertises online checks, which makes me think that the core pg_checksum might still not have merged any code for online checking yet but i wanted to confirm with someone - my easiest options for online verifying checksums would be to trigger pg_basebackup then check pg_stat_database, or to install michael's utility? -Jeremy
On Fri, Apr 18, 2025 at 5:18 PM Jeremy Schneider <schneider@ardentperf.com> wrote:
i should know the answer to this... but asking anyway
i think there had been some mailing list discussions years ago? the
pg_checksum utility in core still can't do an online check right?
"The server must be shut down cleanly before running pg_checksums."
looking around, i think that michael's pg_checksums_ext still seems to
be available in debian repos, and it advertises online checks, which
makes me think that the core pg_checksum might still not have merged
any code for online checking yet
but i wanted to confirm with someone - my easiest options for online
verifying checksums would be to trigger pg_basebackup then check
pg_stat_database, or to install michael's utility?
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!
On Fri, 18 Apr 2025 17:32:19 -0400 Ron Johnson <ronljohnsonjr@gmail.com> wrote: > On Fri, Apr 18, 2025 at 5:18 PM Jeremy Schneider > <schneider@ardentperf.com> wrote: > > > i think there had been some mailing list discussions years ago? the > > pg_checksum utility in core still can't do an online check right? > > > > https://www.postgresql.org/docs/17/app-pgchecksums.html > > "The server must be shut down cleanly before running pg_checksums." Yes I read the docs. This utility has evolved over time including a complete rename, and I was just doublechecking here that we didn't miss a doc update in case this sentence applied to enable/disable but not to verify. As I said I'm assuming it's all accurate but just doing the paranoid double-check -Jeremy
On Fri, Apr 18, 2025 at 5:18 PM Jeremy Schneider <schneider@ardentperf.com> wrote:
but i wanted to confirm with someone - my easiest options for online
verifying checksums would be to trigger pg_basebackup then check
pg_stat_database, or to install michael's utility?
Your easiest option is to just use pgbackrest, which verifies checksums as part of its process. So you are guaranteed to have every page verified at least as often as every full backup.
Cheers,
Greg
--
Crunchy Data - https://www.crunchydata.com
Enterprise Postgres Software Products & Tech Support
iirc there used to be a Google snippet that did online checksum verification. it worked pretty well , but I did not let it run the tests of the extension, so it may not be 100% , I just used it for a quick check if there were other problems visible.
if it's archived now well :)
https://github.com/google/pg_page_verification
On Sat, Apr 19, 2025, 9:00 PM Greg Sabino Mullane <htamfids@gmail.com> wrote:
On Fri, Apr 18, 2025 at 5:18 PM Jeremy Schneider <schneider@ardentperf.com> wrote:but i wanted to confirm with someone - my easiest options for online
verifying checksums would be to trigger pg_basebackup then check
pg_stat_database, or to install michael's utility?Your easiest option is to just use pgbackrest, which verifies checksums as part of its process. So you are guaranteed to have every page verified at least as often as every full backup.Cheers,Greg--Crunchy Data - https://www.crunchydata.comEnterprise Postgres Software Products & Tech Support