Hi All, I note that HDD cluster commit delay improves after i turn off HDD cache. However, i also note that not all HDDs are able to turn off the cache. special I found that two HDD with same model number, one can turn off, anther doesn't. i guess i have my system config or something different setting with two HDDs. Below is my command to turn off the HDD cache. root@lahost008:~# sdparm --set WCE=0 /dev/sdb /dev/sdb: ATA ST10000NE000-3AP EN01 root@lahost008:~# cat /sys/block/sdb/queue/write_cache write through I also tried sdparm to run "sdparm --set WCE=0 /dev/sdb" I got the same result. Anyone experienced this can advise? Thanks a lot _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx