Just old kernels, as they didn't correctly provide all the barriers and other ordering constraints necessary for the write cache to be used safely. -Greg Software Engineer #42 @ http://inktank.com | http://ceph.com On Tue, Jul 16, 2013 at 9:20 AM, Da Chun <ngugc@xxxxxx> wrote: > In this doc, > http://ceph.com/docs/master/rados/configuration/filesystem-recommendations/ > > It says, > > Ceph aims for data safety, which means that when the Ceph Client receives > notice that data was written to a storage drive, that data was actually > written to the storage drive. For old kernels (<2.6.33), disable the write > cache if the journal is on a raw drive. Newer kernels should work fine. > > Use hdparm to disable write caching on the hard disk: > > sudo hdparm -W 0 /dev/hda > > Does it mean the disk write cache should be always disabled for ceph, or > just when using the old kernel (<2.6.33)? > > Thanks for your time! > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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