Date: Wed, 29 Jul 2015 14:13:48 -0700 From: javocado <javocado@gmail.com> To: FreeBSD Filesystems <freebsd-fs@freebsd.org> Subject: Re: pw operations slow under zfs load Message-ID: <CAP1HOmTXTau5nALRCmpgQRoS%2B=sRMhKPd8L-t_us1_xG26XeTg@mail.gmail.com> In-Reply-To: <CAP1HOmTuxi7HL0_-SLJ8pd9s=3ob2D_ZU0pu%2BMSZfuxMPDydWw@mail.gmail.com> References: <CAP1HOmTuxi7HL0_-SLJ8pd9s=3ob2D_ZU0pu%2BMSZfuxMPDydWw@mail.gmail.com>
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Sorry, the boot disk (SSD) is plain old ufs. On Wed, Jul 29, 2015 at 2:11 PM, javocado <javocado@gmail.com> wrote: > Hi, > > We have a pretty busy ZFS pool running on an 8.3 AMD system. We are > noticing that when the pool is busy pw-related operations seem to take a > long time to complete: > > # time pw unlock 1000 > 0.007u 0.036s 0:39.72 0.0% 45+1953k 0+113io 0pf+0w > > # time pw lock 1000 > 0.032u 0.022s 1:09.63 0.0% 24+1132k 0+114io 0pf+0w > > Wile the command is running, we note that the process is locked in the D > state: > > root 85051 0.0 0.0 5832 960 0 D+ 1:53PM 0:00.02 > /usr/sbin/pwd_mkdb -u 1000 /etc/master.passwd > > We also note that there is next to 0 disk activity on the boot volume: > > # gstat -f ad > > dT: 1.005s w: 1.000s filter: ad > L(q) ops/s r/s kBps ms/r w/s kBps ms/w %busy Name > 0 0 0 0 0.0 0 0 0.0 0.0| ad6 > 0 0 0 0 0.0 0 0 0.0 0.0| ad8 > 0 0 0 0 0.0 0 0 0.0 0.0| ad10 > 0 0 0 0 0.0 0 0 0.0 0.0| ad12 > > And plenty of free mem: > > Mem: 400M Active, 3391M Inact, 128G Wired, 1935M Cache, 14G Buf, 6055M Free > > So, what's going on here? How does a busy pool with it's own set of drives > (which operate off an HBA) affect the speed of operations involving the > boot volume (an SSD connected to the mobo)? > >
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