Re: Slow filesystem.

[Eric Sandeen <sandeen@redhat.com>]

On 5/13/11 7:59 AM, Rogier Wolff wrote:
> 
> Hi
> 
> My work (as in what brings in money to buy things from) file-system is
> now "slow as hell". Last time this happened you guys told me that this
> was because I had millions of hardlinks and way too many files.
> 
> Filesystem            Inodes   IUsed   IFree IUse% Mounted on
> /dev/md0                815M    4.1M    811M    1% /recover2
> 
> I have only 4.1M files. Only 1% inodes "in use". 
> 
> 
> The filesystem was filling up lately, but i've managed to create some
> free space.
> 
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/md0              6.3T  5.3T  720G  89% /recover2
> 
>  The question is: How do I get the filesystem to perform
> normally again?
> 
> 
> All mkdir calls are taking around 62 milliseconds: 
> 
> 14:57:02 mkdir("...ME_25c8e/", 0777) = 0 <0.062312>
> 14:57:02 mkdir("...ME_112ff/", 0777) = 0 <0.062658>
> 14:57:02 mkdir("...ME_183cf/", 0777) = 0 <0.062344>

I don't know what the workload is, and "slow" isn't very well characterized here, but from this can I assume that mkdir is the bottleneck?

Did you ever try that patch I sent you for this issue in March?

Using oprofile to see where the fs is spending its time might also be useful.

-Eric

> while on my workstation where i'm not supposed to be working
> with client-data I get: 
> 
> 14:58:18 mkdir("...ME_2a6c6/", 0777) = 0 <0.000033>
> 14:58:18 mkdir("...ME_2b3d9/", 0777) = 0 <0.000031>
> 14:58:18 mkdir("...ME_2c63f/", 0777) = 0 <0.000034>
> 
> So, things on my big datastorage drive are about 2000 times slower
> than on my workstation.
> 
> 	Roger. 
>