Hi, 11 mai 2016 03:10 "Eric Wheeler" <bcache@xxxxxxxxxxxxxxxxxx> a écrit: > Can you describe your disk stack in more detail? What is below ceph? > > I think this is the first time I've heard of Ceph being used in a bcache > stack on the list. Are there any others out there with success? If so, > what kernel versions and disk stack configuration? I'm using one SSD as caching device (one cache set) and several SATA drives as backing devices. No RAID, no MD, no LVM, nothing fancy, only bare devices and Bcache. Bcache devices are XFS formatted and used by Ceph OSD (journaling on the same device). One OSD per bcache device. > So you are using one cache for multiple backing devices in a single cache > set? I remember seeing a thread on the list about someone having a > similar issue (multiple backends, but not ceph). I put some time into > looking for the thread, it might be this one: > bcache: Fix writeback_thread never writing back incomplete stripes. > > but there was a patch for that which should be in 4.4.y back in March. > > Make sure you have this commit: > > https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=a556b804dfa654f054f3 > 304c2c4d274ffe81f92 My kernel already has this commit. > Also, does your backing device(s) set raid_partial_stripes_expensive=1 in > queue_limits (eg, md raid5/6)? I've seen bugs around that flag that might > not be fixed yet. Nope. This is set to 0. Regards, -- Yannis Aribaud -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
