[lustre-discuss] OSS read cache disappeared?

[Thomas Roth]

Hi all,

on two 2.10.3-systems (one of them a fresh test installation) the paramters for the OSS read cache "do 
not exist":

lxfstest02 ~# lctl get_param obdfilter.*.read_cache_enable
error: get_param: param_path 'obdfilter/*/read_cache_enable': No such file or directory


Indeed, only dead links in obdfilter.* :

lxfstest02 ~# ls -l /proc/fs/lustre/obdfilter/test-OST0009

lrwxrwxrwx  1 root root 48 Dec 11 13:01 read_cache_enable -> 
../../osd-zfs/hebetest-OST0009/read_cache_enable
lrwxrwxrwx  1 root root 53 Dec 11 13:01 readcache_max_filesize -> 
../../osd-zfs/hebetest-OST0009/readcache_max_filesize
lrwxrwxrwx  1 root root 56 Dec 11 13:01 writethrough_cache_enable -> 
../../osd-zfs/hebetest-OST0009/writethrough_cache_enable




lxfstest02 ~# ls -l /proc/fs/lustre/osd-zfs/test-OST0009/read_cache_enable
ls: cannot access /proc/fs/lustre/osd-zfs/test-OST0009/read_cache_enable: No such file or directory



I was always content with the manual stating
 > By default, read cache is enabled (read_cache_enable=1).
and therefore never checked.

Should I read the release-notes more closely? Is this a ZFS - Feature? (Our ldiskfs - MDTs still have 
that parameter).


Regards,
Thomas


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Thomas Roth
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