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<DIV style="FONT-SIZE: 12pt">I am also interested in the way that how glusterfs
can use FSCache/Cachefiles. I think the FUSE is the important part to change to
use the local cache function of FSCache/Cachefiles.</DIV>
<DIV style="FONT-SIZE: 12pt">In our case, we have to cache a lot of small files
about 100KB average to improve the reading performance. The IO-cache xlator in
Gluster surely does its work,but we want cache data much more than the memory
can hold.</DIV>
<DIV style="FONT-SIZE: 12pt">We have tested the NFS mount mode of GlusterFS, it
works well. :)</DIV>
<DIV style="FONT-SIZE: 12pt">And you know, the NFS mount method is not the
best way to get/put data from/into the Gluster Volume, so I am still
interested in the function of the local cache of gluster native client.</DIV>
<DIV style="FONT-SIZE: 12pt">The gluster dev group has added the problem to
their bug list: </DIV>
<DIV style="FONT-SIZE: 12pt">
<DIV><SPAN
style="WIDOWS: 2; TEXT-TRANSFORM: none; TEXT-INDENT: 0px; LETTER-SPACING: normal; DISPLAY: inline !important; FONT: medium Tahoma; WHITE-SPACE: normal; ORPHANS: 2; FLOAT: none; COLOR: rgb(0,0,0); WORD-SPACING: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px"> </SPAN><A
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href="https://bugzilla.redhat.com/show_bug.cgi?id=883785">https://bugzilla.redhat.com/show_bug.cgi?id=883785</A></DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>Thanks for everybody.</DIV></DIV>
<HR style="WIDTH: 210px; HEIGHT: 1px" align=left color=#b5c4df SIZE=1>
<DIV style="FONT-SIZE: 12pt"><SPAN>Wei Wu</SPAN></DIV>
<DIV> </DIV>
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<DIV><B>发件人：</B> <A href="mailto:sjayaraman@suse.com">Suresh
Jayaraman</A></DIV>
<DIV><B>发送时间：</B> 2012-12-06 17:47</DIV>
<DIV><B>收件人：</B> <A href="mailto:wuwei.tsh@gmail.com">吴巍</A></DIV>
<DIV><B>抄送：</B> <A href="mailto:anand.avati@gmail.com">Anand Avati</A>; <A
href="mailto:ricwheeler@gmail.com">Ric Wheeler</A>; <A
href="mailto:gluster-users@gluster.org">gluster-users</A>; <A
href="mailto:linux-cachefs@redhat.com">linux-cachefs</A>; <A
href="mailto:gluster-devel@nongnu.org">gluster-devel</A></DIV>
<DIV><B>主题：</B> Re: [Gluster-users] [Linux-cachefs] [Gluster-devel] Can I
use FSCache/Cachefiles with Gluster Native Client mode?</DIV></DIV></DIV>
<DIV>
<DIV>On 12/06/2012 12:24 AM, Anand Avati wrote:</DIV>
<DIV>> I believe FSCache must first be implemented in FUSE before any userspace</DIV>
<DIV>> filesystem (like GlusterFS) can make use of it?</DIV>
<DIV>> </DIV>
<DIV> </DIV>
<DIV>Sounds about right to me. Then, FUSE can ask FS-Cache to store / fetch</DIV>
<DIV>data on behalf of Glusterfs.</DIV>
<DIV> </DIV>
<DIV>> On Wed, Dec 5, 2012 at 1:29 AM, 吴巍 <wuwei.tsh@gmail.com</DIV>
<DIV>> <mailto:wuwei.tsh@gmail.com>> wrote:</DIV>
<DIV>> __</DIV>
<DIV>> Now I'm sure that Gluster FS native client don't support FSCache.</DIV>
<DIV> </DIV>
<DIV>But wait, why do you really need FS-Cache in your case? If improving</DIV>
<DIV>(re)-read performance is what matters to you, have you already taken a</DIV>
<DIV>look at the IO-Cache translator the Glusterfs provides?</DIV>
<DIV> </DIV>
<DIV>Do you have a really slow network? Do you intend to keep your cache on</DIV>
<DIV>an SSD?</DIV>
<DIV>Note that FS-Cache/Cachefiles is not supposed to improve performance for</DIV>
<DIV>all kinds of workloads.</DIV>
<DIV> </DIV>
<DIV>May be one way to know if your workload can benefit with FS-Cache or not is:</DIV>
<DIV> - enable FS-Cache in NFS and try accessing the Gluster namespace via NFS</DIV>
<DIV> - compare its performance with FS-Cache on NFS disabled</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>> There are no codes about FSCache in the source code of Gluster FS.</DIV>
<DIV>> the command "mount -t glusterfs server1:/test-volume /mnt/glusterfs</DIV>
<DIV>> -o fsc" will be executed by /sbin/mount.glusterfs, and the "-o fsc"</DIV>
<DIV>> option will be ignored silently. </DIV>
<DIV>> </DIV>
<DIV>> Thanks for everybody.</DIV>
<DIV>> </DIV>
<DIV>> ------------------------------------------------------------------------</DIV>
<DIV>> Wei Wu</DIV>
<DIV>> </DIV>
<DIV>> *From:* Suresh Jayaraman <mailto:sjayaraman@suse.com></DIV>
<DIV>> *Date:* 2012-12-05 15 <tel:2012-12-05%C2%A015>:06</DIV>
<DIV>> *To:* 吴巍 <mailto:wuwei.tsh@gmail.com></DIV>
<DIV>> *CC:* Ric Wheeler <mailto:ricwheeler@gmail.com>; gluster-users</DIV>
<DIV>> <mailto:gluster-users@gluster.org>; linux-cachefs</DIV>
<DIV>> <mailto:linux-cachefs@redhat.com>; gluster-devel</DIV>
<DIV>> <mailto:gluster-devel@nongnu.org></DIV>
<DIV>> *Subject:* Re: [Linux-cachefs] [Gluster-devel] Can I use</DIV>
<DIV>> FSCache/Cachefiles with Gluster Native Client mode?</DIV>
<DIV>> On 12/03/2012 05:59 PM, Ric Wheeler wrote:</DIV>
<DIV>> > On 12/02/2012 10:29 PM, 吴巍 wrote:</DIV>
<DIV>> >> Hey,</DIV>
<DIV>> >></DIV>
<DIV>> >> I Download the GlusterFS 3.2.7 Release and it works well. And I want</DIV>
<DIV>> >> to improve the reading performance with FSCache/Cachefiles model.</DIV>
<DIV>> >> I use the command line:</DIV>
<DIV>> >> mount -t glusterfs server1:/test-volume /mnt/glusterfs -o fsc</DIV>
<DIV>> >> and no error reported. But the local cache function of FSCache is not</DIV>
<DIV>> </DIV>
<DIV>> Does Glusterfs support fscache? File systems typically have to be</DIV>
<DIV>> modified to include support for fscache (see fs/cifs/fscache*.[c,h] or</DIV>
<DIV>> fs/nfs/fscache*.[c,h] in the kernel source for example). IOW, they have</DIV>
<DIV>> to be fscache aware to be able to use the persistent disk caching.</DIV>
<DIV>> </DIV>
<DIV>> Have you checked if the option 'fsc' is being silently ignored? Try</DIV>
<DIV>> mounting with '-vvv' to see whether it reveals more.</DIV>
<DIV>> </DIV>
<DIV>> What do you mean by "local cache function of FSCache is not active"? Did</DIV>
<DIV>> you mean that the files are not getting cached? or File are not being</DIV>
<DIV>> fetched from the cache when re-read?</DIV>
<DIV>> </DIV>
<DIV>> If it is already supported, are you running the cachefilesd user-space</DIV>
<DIV>> daemon?</DIV>
<DIV>> </DIV>
<DIV>> FS-Cache by default uses /var/cache/fscache dir for caching. You could</DIV>
<DIV>> check whether the cached files are being seen there.</DIV>
<DIV>> </DIV>
<DIV>> Also, /proc/fs/fscache/stats might reveal more details about pages</DIV>
<DIV>> marked for caching, retrieved successfully from cache or cache returned</DIV>
<DIV>> -ENODATA etc.</DIV>
<DIV>> </DIV>
<DIV>> >> active. How can I use the local cache function of FSCache with Gluster</DIV>
<DIV>> >> Native Client mount mode?</DIV>
<DIV>> >></DIV>
<DIV>> > Adding in the fscache list to see if anyone there has experimented with</DIV>
<DIV>> > this,</DIV>
<DIV>> > </DIV>
<DIV> </DIV>
<DIV>-- </DIV>
<DIV>Suresh Jayaraman</DIV></DIV></BODY></HTML>