On 08/02/2012 12:02 PM, Mark Nelson wrote: > On 8/2/12 11:13 AM, Tommi Virtanen wrote: >> Sounds like bcache in writeback mode. Assumes all underlying block >> devices are RAIDed, or losing one will mean losing data; that is, for >> example RAID1(SSD+SSD) & RAID5(8*HDD). >> >> http://www.lessfs.com/wordpress/?p=776 >> -- >> 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 >> > > Neat! I'll try to play with it once the test hardware all makes it in. > > Alex is also trying to bug the XFS guys (and Sage bugged the BTRFS guys) > about ways to put metadata on SSD while keeping data on spinning disk. I have the XFS patch. It's based on pretty old kernel code. I began porting it forward yesterday but it was taking too long so I set it aside. I'll pick it up again soon to see if I can get through it. -Alex > It sounds like there is a hack for XFS that would let us keep inodes in > the lower portion of a volume up to some configurable boundary and then > we could use lvm to assign that portion of the volume to an SSD. The > BTRFS guys have a SOC project in the works to separate out metadata onto > another disk. > > I think these kinds of things could really help our small request > performance. > > Mark > > -- > 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 > > -- 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
