Date: Sun, 17 Jun 2018 18:04:35 -0500 From: Adam <amvandemore@gmail.com> To: tech-lists <tech-lists@zyxst.net> Cc: "freebsd-stable@freebsd.org" <freebsd-stable@freebsd.org> Subject: Re: lightly loaded system eats swap space Message-ID: <CA%2BtpaK3iy%2BD3OLa019jxQ-QMqA3MqStUVU0zcOodjP1oyfNAsg@mail.gmail.com> In-Reply-To: <c8277497-ffcf-0503-490b-96d1b4605af7@zyxst.net> References: <c8277497-ffcf-0503-490b-96d1b4605af7@zyxst.net>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Jun 17, 2018 at 5:19 PM, tech-lists <tech-lists@zyxst.net> wrote: > Hello list, > > context is (server) > freebsd-11-stable r333874, ZFS raidz1-0 (3x4TB disks), 128GB RAM, E5-2630 > @2.3GHz, generic kernel. > > There's one bhyve guest on this server (using 4x cpu and 16GB RAM, also > freebsd-11-stable) > > There have been no special options for zfs configuration on the server, > apart from several datasets having the compressed property set (lz4). > > The server runs nothing else really apart from sshd and it uses ntpd to > sync local time. > > How come such a lightly loaded server with plenty of resources is eating > up swap? If I run two bhyve instances, i.e. two of the same size as > indicated above, so 32GB used for the bhyves, I'll get out-of-swapspace > errors in the daily logs: > > +swap_pager_getswapspace(24): failed > +swap_pager_getswapspace(24): failed > +swap_pager_getswapspace(24): failed > > Here's top, with one bhyve instance running: > > last pid: 49494; load averages: 0.12, 0.13, 0.88 > > up 29+11:36:06 22:52:45 > 54 processes: 1 running, 53 sleeping > CPU: 0.4% user, 0.0% nice, 0.4% system, 0.3% interrupt, 98.9% idle > Mem: 8664K Active, 52M Inact, 4797M Laundry, 116G Wired, 1391M Buf, 4123M > Free > ARC: 108G Total, 1653M MFU, 105G MRU, 32K Anon, 382M Header, 632M Other > 103G Compressed, 104G Uncompressed, 1.00:1 Ratio > Swap: 4096M Total, 3502M Used, 594M Free, 85% Inuse > > PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU > COMMAND > 49491 root 1 4 0 16444K 12024K select 9 0:12 6.49% ssh > 32868 root 12 20 0 9241M 4038M kqread 2 23.2H 1.30% bhyve > 49490 root 1 20 0 10812K 6192K sbwait 5 0:02 0.88% sftp > > From the looks of it, a huge amount of ram is wired. Why is that, and how > would I debug it? > That seems to be shown in the output you provided: ARC: 108G Total, 1653M MFU, 105G MRU, 32K Anon, 382M Header, 632M Other > > A server of similar spec which is running freebsd-current with seven bhyve > instances doesn't have this issue: > Based upon the output neither ram nor swap seems like similar spec so I wonder if you could say what you mean by that. -- Adam
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?CA%2BtpaK3iy%2BD3OLa019jxQ-QMqA3MqStUVU0zcOodjP1oyfNAsg>