ost-survey on this environment

mds, oss: lustre 2.4.2 (CentOS 6.5 with lustre patched kernel RPM)
client: lustre 2.4.2 (CentOS 6.5 patchless client, lustre iokit 1.4.0.1)

command line: ost-survey -s 100 /lustre

will hang, chewing all the CPU in the attempt to
echo 0 in /proc/fs/lustre/llite/*/max_cached_mb . This is due to the
subroutine cache_off in the ost-survey script.

In a lustre client 2.1.6 the max_cached_mb appears as
a single number

1. cat /proc/fs/lustre/llite/*/max_cached_mb
   18114

but on a 2.4.2 client is different

1. cat /proc/fs/lustre/llite/*/max_cached_mb
   users: 2
   max_cached_mb: 96766
   used_mb: 21806
   unused_mb: 74960
   reclaim_count: 0

So probably the script has not been fixed to work with the new output.