[lustre-discuss] OSS read cache disappeared?

Thomas Roth t.roth at gsi.de
Wed Dec 11 04:09:19 PST 2019

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 -> 
lrwxrwxrwx  1 root root 53 Dec 11 13:01 readcache_max_filesize -> 
lrwxrwxrwx  1 root root 56 Dec 11 13:01 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).


Thomas Roth
Department: Informationstechnologie
Location: SB3 2.291
Phone: +49-6159-71 1453  Fax: +49-6159-71 2986

GSI Helmholtzzentrum für Schwerionenforschung GmbH
Planckstraße 1, 64291 Darmstadt, Germany, www.gsi.de

Commercial Register / Handelsregister: Amtsgericht Darmstadt, HRB 1528
Managing Directors / Geschäftsführung:
Professor Dr. Paolo Giubellino, Ursula Weyrich, Jörg Blaurock
Chairman of the Supervisory Board / Vorsitzender des GSI-Aufsichtsrats:
State Secretary / Staatssekretär Dr. Georg Schütte

More information about the lustre-discuss mailing list