Jonathan Chen
2016-Oct-20 21:18 UTC
zfs, a directory that used to hold lot of files and listing pause
On 21 October 2016 at 09:09, Peter <pmc at citylink.dinoex.sub.org> wrote: [...]> > I see this on my pgsql_tmp dirs (where Postgres stores intermediate > query data that gets too big for mem - usually lots of files) - in > normal operation these dirs are completely empty, but make heavy disk > activity (even writing!) when doing ls. > Seems normal, I dont care as long as the thing is stable. One would need > to check how ZFS stores directories and what kind of fragmentation can > happen there. Or wait for some future feature that would do > housekeeping. ;)I'm seeing this as well with an Odoo ERP running on Postgresql. This lag does matter to me as this is huge performance hit when running Postgresql on ZFS, and it would be good to see this resolved. pg_restores can make the system crawl as well. Cheers. -- Jonathan Chen <jonc at chen.org.nz>
Chris Watson
2016-Oct-20 22:07 UTC
zfs, a directory that used to hold lot of files and listing pause
While I have yet to encounter this with PG on ZFS, knock on wood, this obviously is not an isolated issue and if possible those experiencing it should do as much investigation as possible and open a PR. This seems like something I'm going to read about FreeBSD and PG/ZFS over at Hacker News from a Linux switcher as they explain why they went back to Linux in the future. It's not a show stopper but it's obviously an issue. Chris Sent from my iPhone 5> On Oct 20, 2016, at 4:18 PM, Jonathan Chen <jonc at chen.org.nz> wrote: > >> On 21 October 2016 at 09:09, Peter <pmc at citylink.dinoex.sub.org> wrote: >> [...] >> >> I see this on my pgsql_tmp dirs (where Postgres stores intermediate >> query data that gets too big for mem - usually lots of files) - in >> normal operation these dirs are completely empty, but make heavy disk >> activity (even writing!) when doing ls. >> Seems normal, I dont care as long as the thing is stable. One would need >> to check how ZFS stores directories and what kind of fragmentation can >> happen there. Or wait for some future feature that would do >> housekeeping. ;) > > I'm seeing this as well with an Odoo ERP running on Postgresql. This > lag does matter to me as this is huge performance hit when running > Postgresql on ZFS, and it would be good to see this resolved. > pg_restores can make the system crawl as well. > > Cheers. > -- > Jonathan Chen <jonc at chen.org.nz> > _______________________________________________ > freebsd-stable at freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe at freebsd.org"
Steven Hartland
2016-Oct-20 22:27 UTC
zfs, a directory that used to hold lot of files and listing pause
On 20/10/2016 22:18, Jonathan Chen wrote:> On 21 October 2016 at 09:09, Peter <pmc at citylink.dinoex.sub.org> wrote: > [...] >> I see this on my pgsql_tmp dirs (where Postgres stores intermediate >> query data that gets too big for mem - usually lots of files) - in >> normal operation these dirs are completely empty, but make heavy disk >> activity (even writing!) when doing ls. >> Seems normal, I dont care as long as the thing is stable. One would need >> to check how ZFS stores directories and what kind of fragmentation can >> happen there. Or wait for some future feature that would do >> housekeeping. ;) > I'm seeing this as well with an Odoo ERP running on Postgresql. This > lag does matter to me as this is huge performance hit when running > Postgresql on ZFS, and it would be good to see this resolved. > pg_restores can make the system crawl as well.As mentioned before could you confirm you have disable atime?