Re: 3x read to write ratio on dump/restore

2009-01-13 Thread Peter Jeremy
On 2009-Jan-12 05:05:37 -0500, Yoshihiro Ota wrote: >Jermey, I tought you wrote this, >http://lists.freebsd.org/pipermail/freebsd-hackers/2007-February/019666.html. Yes, that is my message. I had forgotten it. If you dig back further, you'll find that I looked into the poor read behaviour of du

Re: gcache [was: Re: 3x read to write ratio on dump/restore]

2009-01-12 Thread Yoshihiro Ota
On Mon, 12 Jan 2009 11:41:11 +0100 Christoph Mallon wrote: > Yoshihiro Ota schrieb: > > Try GEOM Cache(gcache). > > Just a side note: gcache does not seem to have any documentation. "man > gcache" is unsuccessful, geom(8) does not mention it (geom and gcache > are the same hardlinked binary).

Re: gcache [was: Re: 3x read to write ratio on dump/restore]

2009-01-12 Thread Matthew Seaman
-BEGIN PGP SIGNED MESSAGE- Hash: RIPEMD160 Christian Brueffer wrote: | On Mon, Jan 12, 2009 at 11:41:11AM +0100, Christoph Mallon wrote: |> Yoshihiro Ota schrieb: |>> Try GEOM Cache(gcache). |> Just a side note: gcache does not seem to have any documentation. "man |> gcache" is unsuccessf

Re: gcache [was: Re: 3x read to write ratio on dump/restore]

2009-01-12 Thread Christian Brueffer
On Mon, Jan 12, 2009 at 11:41:11AM +0100, Christoph Mallon wrote: > Yoshihiro Ota schrieb: > >Try GEOM Cache(gcache). > > Just a side note: gcache does not seem to have any documentation. "man > gcache" is unsuccessful, geom(8) does not mention it (geom and gcache > are the same hardlinked binar

Re: gcache [was: Re: 3x read to write ratio on dump/restore]

2009-01-12 Thread Ivan Voras
Christoph Mallon wrote: > Yoshihiro Ota schrieb: >> Try GEOM Cache(gcache). > > Just a side note: gcache does not seem to have any documentation. "man > gcache" is unsuccessful, geom(8) does not mention it (geom and gcache > are the same hardlinked binary). Is there information about it somewhere?

Re: 3x read to write ratio on dump/restore

2009-01-12 Thread Ollivier Robert
According to M. Warner Losh: > The read kBps was 3x the write kBps. While the dump is going through > the raw device, and the restore is going through the file system, I > can't imagine why we'd have such a huge difference that would be utter > consistent for the whole 15 hour run. dump launches

gcache [was: Re: 3x read to write ratio on dump/restore]

2009-01-12 Thread Christoph Mallon
Yoshihiro Ota schrieb: Try GEOM Cache(gcache). Just a side note: gcache does not seem to have any documentation. "man gcache" is unsuccessful, geom(8) does not mention it (geom and gcache are the same hardlinked binary). Is there information about it somewhere? __

Re: 3x read to write ratio on dump/restore

2009-01-12 Thread Yoshihiro Ota
Jermey, I tought you wrote this, http://lists.freebsd.org/pipermail/freebsd-hackers/2007-February/019666.html. Try GEOM Cache(gcache). It will be like, $ gcache create temp -s /dev/XXYsZ $ dump /dev/cache/temp <...> It's been 9 months since I tested so I don't remember about the detail numbe

Re: 3x read to write ratio on dump/restore

2009-01-10 Thread Peter Jeremy
On 2009-Jan-09 09:50:27 -0700, "M. Warner Losh" wrote: >The read kBps was 3x the write kBps. ... >Any ideas what gives? I observed this with 16MB cache and with 32MB >cache, fwiw. I've seen this as well. AFAIK, this is a side-effect of dump's caching. My top-of-head explanation is that each du

Re: 3x read to write ratio on dump/restore

2009-01-10 Thread M. Warner Losh
In message: <20090111041710.gb5...@server.vk2pj.dyndns.org> Peter Jeremy writes: : On 2009-Jan-09 09:50:27 -0700, "M. Warner Losh" wrote: : >The read kBps was 3x the write kBps. : ... : >Any ideas what gives? I observed this with 16MB cache and with 32MB : >cache, fwiw. : : I've see

Re: 3x read to write ratio on dump/restore

2009-01-09 Thread Daan Vreeken [PA4DAN]
Hi Warner, On Friday 09 January 2009 17:50:27 M. Warner Losh wrote: > I just copied a disk using dump + restore. I noticed something > through the whole run of this 500GB operation: > > L(q) ops/sr/s kBps ms/rw/s kBps ms/w %busy Name > 3231231 147549.5 0

3x read to write ratio on dump/restore

2009-01-09 Thread M. Warner Losh
I just copied a disk using dump + restore. I noticed something through the whole run of this 500GB operation: L(q) ops/sr/s kBps ms/rw/s kBps ms/w %busy Name 3231231 147549.5 0 00.0 97.5| da1s1a 0 39 0 00.0 39 4982