[OpenAFS] Documentation on fs bypassthreshold?
Phillip Moore
w.phillip.moore@gmail.com
Mon, 18 Oct 2010 13:34:41 -0400
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Thanks for the explanation.
Can someone familiar with the new feature tell me if I'm off base in
asserting that it is a bug that this can be set, but not UN-set?
Sure looks like a bug to me....
On Mon, Oct 18, 2010 at 1:29 PM, Matt W. Benjamin <matt@linuxbox.com> wrote:
> Hi Phil,
>
> This fs operation gets, or sets, a threshold (relative to file size) for
> cache bypass. You need to be using a CM port with bypass support, i.e.,
> Linux right now. By default, all reads and writes are through the CM's
> cache. There is no threshold unless set, so by default cache bypass is not
> operative. If you (cm administrator) set a value here, reads on files
> greater than the threshold size use the cache bypass strategy. Cache bypass
> reads are performed in the background queue, into the page cache only. You
> probably want to increase CM daemon threads should you enable this.
>
> Matt
>
> ----- "Phillip Moore" <w.phillip.moore@gmail.com> wrote:
>
> > In 1.5.77, there's no man page for fs_bypassthreshold, and Google's
> > not showing much that helps, either.
> >
> >
> > Can someone explain to me what this does? For the purposes of
> > supporting it in AFS::Command, I only need to know the CLI syntax, and
> > I can read venus/fs.c to figure out how to parse the output, but...
> >
> >
> > What does it DO?
>
> --
>
> Matt Benjamin
>
> The Linux Box
> 206 South Fifth Ave. Suite 150
> Ann Arbor, MI 48104
>
> http://linuxbox.com
>
> tel. 734-761-4689
> fax. 734-769-8938
> cel. 734-216-5309
>
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<div><br></div>Thanks for the explanation.<div><br></div><div>Can someone f=
amiliar with the new feature tell me if I'm off base in asserting that =
it is a bug that this can be set, but not UN-set?</div><div><br></div><div>
Sure looks like a bug to me....</div><div><br></div><div><div class=3D"gmai=
l_quote">On Mon, Oct 18, 2010 at 1:29 PM, Matt W. Benjamin <span dir=3D"ltr=
"><<a href=3D"mailto:matt@linuxbox.com">matt@linuxbox.com</a>></span>=
wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex;">Hi Phil,<br>
<br>
This fs operation gets, or sets, a threshold (relative to file size) for ca=
che bypass. =A0You need to be using a CM port with bypass support, i.e., Li=
nux right now. =A0By default, all reads and writes are through the CM's=
cache. =A0There is no threshold unless set, so by default cache bypass is =
not operative. =A0If you (cm administrator) set a value here, reads on file=
s greater than the threshold size use the cache bypass strategy. =A0Cache b=
ypass reads are performed in the background queue, into the page cache only=
. =A0You probably want to increase CM daemon threads should you enable this=
.<br>
<br>
Matt<br>
<div><div></div><div class=3D"h5"><br>
----- "Phillip Moore" <<a href=3D"mailto:w.phillip.moore@gmail=
.com">w.phillip.moore@gmail.com</a>> wrote:<br>
<br>
> In 1.5.77, there's no man page for fs_bypassthreshold, and Google&=
#39;s<br>
> not showing much that helps, either.<br>
><br>
><br>
> Can someone explain to me what this does? For the purposes of<br>
> supporting it in AFS::Command, I only need to know the CLI syntax, and=
<br>
> I can read venus/fs.c to figure out how to parse the output, but...<br=
>
><br>
><br>
> What does it DO?<br>
<br>
</div></div>--<br>
<br>
Matt Benjamin<br>
<br>
The Linux Box<br>
206 South Fifth Ave. Suite 150<br>
Ann Arbor, MI =A048104<br>
<br>
<a href=3D"http://linuxbox.com" target=3D"_blank">http://linuxbox.com</a><b=
r>
<br>
tel. 734-761-4689<br>
fax. 734-769-8938<br>
cel. 734-216-5309<br>
</blockquote></div><br></div>
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