[OpenAFS] accessing R/O volume becomes slow

[Benjamin Kaduk]

On Wed, 26 Nov 2014, Hans-Werner Paulsen wrote:

> Hello,
> this is on Linux 3.14.8 x86_64, and OpenAFS 1.6.9. The machine is running
> normally for several months, and then accessing a specific R/O volume (e.g. ls
> -lR <large_volume>) becomes slow. Accessing the R/W version of this volume
> works normally. Accessing other R/O volumes, which have the same size and
> number of files, works normally. Accessing the R/O version of the problem
> volume from other clients works normally.
> The command "fs flushall" does not solve the problem. The (second) "ls -lR"
> command needs 10 seconds on the R/O, and 2 seconds on the R/W version of this
> volume.
> Accessing the R/O version from other fileservers (using fs setserverprefs)
> does not change anything.
> Checking the machine I see more than 5 million of afs_inode_cache slab
> entries. Is this normal? Any hint how to proceed?

Are accesses from the same client to other volumes on the same (slow)
fileserver slow or fast?  Maybe you are getting throttled for too many
failed RPCs...

-Ben