Re: [PATCH 00/37] Permit filesystem local caching

From: David Howells
Date: Fri Feb 22 2008 - 11:16:55 EST


David Howells <dhowells@xxxxxxxxxx> wrote:

> > > Have you got before/after benchmark results?
> >
> > See attached.
>
> Attached here are results using BTRFS (patched so that it'll work at all)
> rather than Ext3 on the client on the partition backing the cache.

And here are XFS results.

Tuning XFS makes a *really* big difference for the lots of small/medium files
being tarred case. However, in general BTRFS is much better.

David
---


=========================
FEW BIG FILES TEST ON XFS
=========================

Completely cold caches:

[root@andromeda ~]# time cat /warthog/bigfile >/dev/null
real 0m2.286s
user 0m0.000s
sys 0m1.828s
[root@andromeda ~]# time cat /warthog/biggerfile >/dev/null
real 0m4.228s
user 0m0.000s
sys 0m1.360s

Warm NFS pagecache:

[root@andromeda ~]# time cat /warthog/bigfile >/dev/null
real 0m0.058s
user 0m0.000s
sys 0m0.060s
[root@andromeda ~]# time cat /warthog/biggerfile >/dev/null
real 0m0.122s
user 0m0.000s
sys 0m0.120s

Warm XFS pagecache, cold NFS pagecache:

[root@andromeda ~]# time cat /warthog/bigfile >/dev/null
real 0m0.181s
user 0m0.000s
sys 0m0.180s
[root@andromeda ~]# time cat /warthog/biggerfile >/dev/null
real 0m1.034s
user 0m0.000s
sys 0m0.404s

Warm on-disk cache, cold pagecaches:

[root@andromeda ~]# time cat /warthog/bigfile >/dev/null
real 0m1.540s
user 0m0.000s
sys 0m0.256s
[root@andromeda ~]# time cat /warthog/biggerfile >/dev/null
real 0m3.003s
user 0m0.000s
sys 0m0.532s


==========================================
MANY SMALL/MEDIUM FILE READING TEST ON XFS
==========================================

Completely cold caches:

[root@andromeda ~]# time tar cf - /warthog/aaa >/dev/zero
real 4m56.827s
user 0m0.180s
sys 0m6.668s

Warm NFS pagecache:

[root@andromeda ~]# time tar cf - /warthog/aaa >/dev/zero
real 0m15.084s
user 0m0.212s
sys 0m5.008s

Warm XFS pagecache, cold NFS pagecache:

[root@andromeda ~]# time tar cf - /warthog/aaa >/dev/zero
real 0m13.547s
user 0m0.220s
sys 0m5.652s

Warm on-disk cache, cold pagecaches:

[root@andromeda ~]# time tar cf - /warthog/aaa >/dev/zero
real 4m36.316s
user 0m0.148s
sys 0m4.440s


=======================================================
MANY SMALL/MEDIUM FILE READING TEST ON AN OPTIMISED XFS
=======================================================

mkfs.xfs -d agcount=4 -l size=128m,version=2 /dev/sda6


Completely cold caches:

[root@andromeda ~]# time tar cf - /warthog/aaa >/dev/zero
real 3m44.033s
user 0m0.248s
sys 0m6.632s

Warm on-disk cache, cold pagecaches:

[root@andromeda ~]# time tar cf - /warthog/aaa >/dev/zero
real 3m8.582s
user 0m0.108s
sys 0m3.420s
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