My load on my i7 920 is certainly higher when I add a 8GB usb stick as
a ZFS cache device.
It seems to use about 10% system load - If I remove the cache device
it drops about 10%. Anyone else seeing this?
With cache device:
CPU: 0.0% user, 0.0% nice, 10.3% system, 0.0% interrupt, 91.5% idle
Mem: 822M Active, 9101M Inact, 1542M Wired, 34M Cache, 1237M Buf, 375M Free
Swap: 8192M Total, 200K Used, 8192M Free
Without:
up 56+01:04:25 21:50:01
137 processes: 1 running, 136 sleeping
CPU: 0.1% user, 0.0% nice, 0.0% system, 0.0% interrupt, 99.9% idle
Mem: 822M Active, 9101M Inact, 1542M Wired, 34M Cache, 1237M Buf, 375M Free
The load reported by top is +0.50 with, and +0.00 without.
FreeBSD 8.1-RELEASE amd64
--
chs,
On Mon, Nov 15, 2010 at 09:50:50PM +0100, Christer Solskogen wrote:> My load on my i7 920 is certainly higher when I add a 8GB usb stick as > a ZFS cache device.USB 1.0? 2.0? Dunno even if that would make a difference... -- Brian Reichert <reichert@numachi.com> 55 Crystal Ave. #286 Derry NH 03038-1725 USA BSD admin/developer at large
According to Christer Solskogen:> See, that is why I think it is a ZFS issue. Because I did that. > I created a UFS filesystem on the same usb stick. Mounted it and did a > "dd if=/dev/zero of=/mnt/file". > The systemload goes +0.6 instead if +10.3.Do not forget that everything that is read/written from/to USB devices goes through the CPU (no DMA or anything for USB devices). -- Ollivier ROBERT -=- FreeBSD: The Power to Serve! -=- roberto@keltia.net In memoriam to Ondine, our 2nd child: http://ondine.keltia.net/
On Wed, Nov 17, 2010 at 7:46 AM, Christer Solskogen <christer.solskogen@gmail.com> wrote:> On Tue, Nov 16, 2010 at 5:55 PM, Christer Solskogen > <christer.solskogen@gmail.com> wrote: > <snip> > > Yesterday I installed 8.1-RELEASE on another machine, made a zpool and > added the same usb device as cache. That machine does not have same > issue as my other machine.I also tried adding a SSD as a cache device to the machine that gets the high load. Same symptoms as if I added a USB stick. Will try to reboot server now to se if that has any impact. -- chs,
On Wed, Nov 17, 2010 at 8:47 AM, Christer Solskogen <christer.solskogen@gmail.com> wrote:> Will try to reboot server now to se if that has any impact.It seems to have solved it. At least temporary. -- chs,
same problem here after ~ 30 days with a production server and 2 SSD Intel X25M as L2. so we update and reboot the 8-STABLE server every month. 2010/11/17 Christer Solskogen <christer.solskogen@gmail.com>> On Wed, Nov 17, 2010 at 8:47 AM, Christer Solskogen > <christer.solskogen@gmail.com> wrote: > > Will try to reboot server now to se if that has any impact. > > It seems to have solved it. At least temporary. > > -- > chs, > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org" >