On May 13, 2011, at 06:59, Rogier Wolff wrote:
> 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
I suspect that the free inodes in your filesystem are very fragmented, due to the filesystem filling up and then deleting a lot of files that create "holes" of free inodes within the inode table blocks. That means that possibly finding free inodes is a bunch of work, and then possibly only one or two inodes are allocated from each block.
> The question is: How do I get the filesystem to perform
> normally again?
It is probably worthwhile to do a blktrace to see what the IO is looking like, and as Eric suggested the oprofile information may be interesting if a lot of CPU is being used.
> 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>
>
> 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.
>
> --
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> ** Delftechpark 26 2628 XH Delft, The Netherlands. KVK: 27239233 **
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Cheers, Andreas
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