On Thu, May 19, 2016 at 7:51 AM, Houlinfei <hou.linfei@xxxxxxx> wrote: > > > Hi, the main ceph-disk interface added is part of the prepare. We add fcache, fcache_size, fcache-uuid optional arguments. These are the only external interface. When you want to use flashcache, you must specify flashcache disk and flashcache size such as > ceph-disk prepare --fcache /dev/sdc --fcache_size 10 /dev/sda. > I think we could add bcache and dm-cache in the same way if needed. What do you think? > > 发件人: Sage Weil [mailto:notifications@xxxxxxxxxx] > 发送时间: 2016年5月7日 3:58 > 收件人: ceph/ceph > 抄送: houlinfei 11802 (RD); Author > 主题: Re: [ceph/ceph] Wip add flashcache (#8773) > > I think we want to make this more generic so that we can layer in any caching option (flashcache, bcache, dm-cache). Can you send an email to ceph-devel with the proposed ceph-disk interface change so we can get feedback and settle one the approach? Thanks! I think it's important to think about how these block caching solutions handle O_DIRECT. Bluestore uses O_DIRECT + libaio which bypasses the normal kernel (page) caches. I actually don't know the answer to it but I think it's valuable to figure out if any of the above are bypassed in the O_DIRECT case. -- Milosz Tanski CTO 16 East 34th Street, 15th floor New York, NY 10016 p: 646-253-9055 e: milosz@xxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
