Date: Sat, 17 Sep 2011 10:54:34 -0700 From: "David P. Discher" <dpd@bitgravity.com> To: Lytochkin Boris <lytboris@gmail.com> Cc: freebsd-fs@freebsd.org Subject: Re: [ZFS] starving reads while idle disks Message-ID: <6B437FA4-B422-4BE7-BDF5-F90717F3865B@bitgravity.com> In-Reply-To: <CAEJYa-Si%2B4Tj5sj8fuxWfqjZgMX1cB8y=JWqJqe_F%2BR4Er9g_A@mail.gmail.com>
index | next in thread | previous in thread | raw e-mail
Do you see the same read-stravation when writing the tar to a file ? (possibly outside the zpool). I have anecdotal suspicion that /dev/null has some performance hit of blocking or locking. -dpd On Sep 17, 2011, at 5:02 AM, Lytochkin Boris wrote: > While runnig `tar cf - . >/dev/null', `vmstat -i' shows ~200 > interrupts per second for mpt. If I enable scrub on that pool, > interrupts bump upto 5k ips resulting 12Mb/s scrub speed and disks > busy percentage raises upto 100%. No warnings are shown in logs in > both cases.home | help
Want to link to this message? Use this
URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?6B437FA4-B422-4BE7-BDF5-F90717F3865B>