2011-05-07 16:09:49

by Justin Piszcz

[permalink] [raw]
Subject: 2.6.38.4: xfs speed problem?

Hello,

Using 2.6.38.4 on two hosts:

Host 1:
$ /usr/bin/time find geocities.data 1> /dev/null
80.92user 417.93system 2:19:07elapsed 5%CPU (0avgtext+0avgdata 105520maxresident)k
0inputs+0outputs (0major+73373minor)pagefaults 0swaps

# xfs_db -c frag -f /dev/sda1
actual 40203982, ideal 40088075, fragmentation factor 0.29%

meta-data=/dev/sda1 isize=256 agcount=44, agsize=268435455 blks
= sectsz=512 attr=2
data = bsize=4096 blocks=11718704640, imaxpct=5
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal bsize=4096 blocks=521728, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

--

Host 2:
$ /usr/bin/time find geocities.data 1>/dev/null
54.60user 337.20system 48:42.71elapsed 13%CPU (0avgtext+0avgdata 105632maxresident)k
0inputs+0outputs (1major+72981minor)pagefaults 0swaps

# xfs_db -c frag -f /dev/sdb1
actual 37998306, ideal 37939331, fragmentation factor 0.16%

meta-data=/dev/sdb1 isize=256 agcount=10, agsize=268435455 blks
= sectsz=512 attr=2
data = bsize=4096 blocks=2441379328, imaxpct=5
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal bsize=4096 blocks=521728, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0


--

Host 1: RAID-6 (7200 RPM Drives, 18+1 hot spare)
Host 2: RAID-6 (7200 RPM Drives, 12)

Each system uses a 3ware 9750-24i4e controller, same settings.

Any thoughts why one is > 2x faster than the other?

Justin.


2011-05-08 00:33:27

by Dave Chinner

[permalink] [raw]
Subject: Re: 2.6.38.4: xfs speed problem?

On Sat, May 07, 2011 at 12:09:46PM -0400, Justin Piszcz wrote:
> Hello,
>
> Using 2.6.38.4 on two hosts:
>
> Host 1:
> $ /usr/bin/time find geocities.data 1> /dev/null
> 80.92user 417.93system 2:19:07elapsed 5%CPU (0avgtext+0avgdata 105520maxresident)k
> 0inputs+0outputs (0major+73373minor)pagefaults 0swaps
>
> # xfs_db -c frag -f /dev/sda1
> actual 40203982, ideal 40088075, fragmentation factor 0.29%
>
> meta-data=/dev/sda1 isize=256 agcount=44, agsize=268435455 blks
> = sectsz=512 attr=2
> data = bsize=4096 blocks=11718704640, imaxpct=5
> = sunit=0 swidth=0 blks
> naming =version 2 bsize=4096 ascii-ci=0
> log =internal bsize=4096 blocks=521728, version=2
> = sectsz=512 sunit=0 blks, lazy-count=1
> realtime =none extsz=4096 blocks=0, rtextents=0
>
> --
>
> Host 2:
> $ /usr/bin/time find geocities.data 1>/dev/null
> 54.60user 337.20system 48:42.71elapsed 13%CPU (0avgtext+0avgdata 105632maxresident)k
> 0inputs+0outputs (1major+72981minor)pagefaults 0swaps
>
> # xfs_db -c frag -f /dev/sdb1
> actual 37998306, ideal 37939331, fragmentation factor 0.16%
>
> meta-data=/dev/sdb1 isize=256 agcount=10, agsize=268435455 blks
> = sectsz=512 attr=2
> data = bsize=4096 blocks=2441379328, imaxpct=5
> = sunit=0 swidth=0 blks
> naming =version 2 bsize=4096 ascii-ci=0
> log =internal bsize=4096 blocks=521728, version=2
> = sectsz=512 sunit=0 blks, lazy-count=1
> realtime =none extsz=4096 blocks=0, rtextents=0
>
>
> --
>
> Host 1: RAID-6 (7200 RPM Drives, 18+1 hot spare)

Those will be 3TB drives

> Host 2: RAID-6 (7200 RPM Drives, 12)

and those are 1TB drives.

Different hardware is guaranteed to give you different performance,
especially from a seek capability perspective.

> Each system uses a 3ware 9750-24i4e controller, same settings.
>
> Any thoughts why one is > 2x faster than the other?

Different filesystem sizes mean different directory, inode and data
layouts, especially if you are using inode64.

Cheers,

Dave.
--
Dave Chinner
[email protected]

2011-05-08 17:18:37

by Stan Hoeppner

[permalink] [raw]
Subject: Re: 2.6.38.4: xfs speed problem?

On 5/7/2011 7:33 PM, Dave Chinner wrote:
> On Sat, May 07, 2011 at 12:09:46PM -0400, Justin Piszcz wrote:
>> Hello,
>>
>> Using 2.6.38.4 on two hosts:
>>
>> Host 1:
>> $ /usr/bin/time find geocities.data 1> /dev/null
>> 80.92user 417.93system 2:19:07elapsed 5%CPU (0avgtext+0avgdata 105520maxresident)k
>> 0inputs+0outputs (0major+73373minor)pagefaults 0swaps
>>
>> # xfs_db -c frag -f /dev/sda1
>> actual 40203982, ideal 40088075, fragmentation factor 0.29%
>>
>> meta-data=/dev/sda1 isize=256 agcount=44, agsize=268435455 blks
>> = sectsz=512 attr=2
>> data = bsize=4096 blocks=11718704640, imaxpct=5
>> = sunit=0 swidth=0 blks
>> naming =version 2 bsize=4096 ascii-ci=0
>> log =internal bsize=4096 blocks=521728, version=2
>> = sectsz=512 sunit=0 blks, lazy-count=1
>> realtime =none extsz=4096 blocks=0, rtextents=0
>>
>> --
>>
>> Host 2:
>> $ /usr/bin/time find geocities.data 1>/dev/null
>> 54.60user 337.20system 48:42.71elapsed 13%CPU (0avgtext+0avgdata 105632maxresident)k
>> 0inputs+0outputs (1major+72981minor)pagefaults 0swaps
>>
>> # xfs_db -c frag -f /dev/sdb1
>> actual 37998306, ideal 37939331, fragmentation factor 0.16%
>>
>> meta-data=/dev/sdb1 isize=256 agcount=10, agsize=268435455 blks
>> = sectsz=512 attr=2
>> data = bsize=4096 blocks=2441379328, imaxpct=5
>> = sunit=0 swidth=0 blks
>> naming =version 2 bsize=4096 ascii-ci=0
>> log =internal bsize=4096 blocks=521728, version=2
>> = sectsz=512 sunit=0 blks, lazy-count=1
>> realtime =none extsz=4096 blocks=0, rtextents=0


How much would it help, if any, with this specific 'test', or with
overall XFS performance, if Justin were to...

>> Host 1: RAID-6 (7200 RPM Drives, 18+1 hot spare)

remake the fs on the above device with 'sw=16' or remount with
appropriate sunit and swidth values?

>> Host 2: RAID-6 (7200 RPM Drives, 12)

remake the fs on the above device with 'sw=10' or remount with
appropriate sunit and swidth values?

--
Stan