Re: XFS unlink still slow on 3.1.9 kernel ?

Richard Ems
2012-02-14T09:48:31Z

Hi Christoph, hi list,

I don;t have ONE dir with that 11 million files, it's one dir with many
directories and a total of about 11 million files AND dirs! See output
below!

On 02/13/2012 10:16 PM, Christoph Hellwig wrote:
> On Mon, Feb 13, 2012 at 07:48:58PM +0100, Richard Ems wrote:
>> I already updated to 3.2.4 and started the same "find dir" command again
>> that previously took 100 min to run. It has been running now for over 30
>> min ...
>>
>> Should this "find" run time also improve ?
>
> No, not by that change anyway.

It didn't improve, 100 min again.

>> Or will only unlink run time improve ?
>
> Yes.

rm took about 110 min.

>> Do I have to mount the XFS partition with some new/old/special option?
>
> I'd have to look into it in more detail. IIRC you said you're using
> RAID6 which can be fairly nasty for small reads. Did you use the
> inode64 mount option on the filesystem?

No, I did not use it, but I was thinking about and ran the script from
http://sandeen.net/misc/summarise_stat.pl and got as an example on /bin:

# /net/c3m/usr/local/software/XFS/summarise_stat.pl /bin/
9 6.2% are scripts (shell, perl, whatever)
65 44.8% don't use any stat() family calls at all
61 42.1% use 32-bit stat() family interfaces only
9 6.2% use 64-bit stat64() family interfaces only
1 0.7% use both 32-bit and 64-bit stat() family interfaces

So I was not sure if I should use inode64 or not.

This are the times that the run took yesterday:

Mon Feb 13 19:14:07 CET 2012

+ wc -l
+ find 2012-02-13/
11377443

real 101m30.811s
user 0m17.365s
sys 1m4.632s

Mon Feb 13 20:55:38 CET 2012

+ wc -l
+ find 2012-02-13/ -type d
834591

real 103m52.686s
user 0m11.765s
sys 1m41.018s

+ wc -l
+ find 2012-02-13/ -type f
10539154

real 104m38.421s
user 0m19.905s
sys 1m47.551s

+ /bin/rm -i -rf 2012-02-13/

real 110m55.764s
user 0m13.401s
sys 4m3.115s

Tue Feb 14 02:15:05 CET 2012

Thanks again,
Richard