HI, What do you think if its design approach goes correctly? Do you have any comments or better design idea for BTRFS hot relocation support? any comments are appreciated, thanks.
On Mon, May 6, 2013 at 4:53 PM, <zwu.ker...@gmail.com> wrote: > From: Zhi Yong Wu <wu...@linux.vnet.ibm.com> > > The patchset as RFC is sent out mainly to see if it goes in the > correct development direction. > > The patchset is trying to introduce hot relocation support > for BTRFS. In hybrid storage environment, when the data in > HDD disk get hot, it can be relocated to SSD disk by BTRFS > hot relocation support automatically; also, if SSD disk ratio > exceed its upper threshold, the data which get cold can be > looked up and relocated to HDD disk to make more space in SSD > disk at first, and then the data which get hot will be relocated > to SSD disk automatically. > > BTRFS hot relocation mainly reserve block space from SSD disk > at first, load the hot data to page cache from HDD, allocate > block space from SSD disk, and finally write the data to SSD disk. > > If you'd like to play with it, pls pull the patchset from > my git on github: > https://github.com/wuzhy/kernel.git hot_reloc > > For how to use, please refer too the example below: > > root@debian-i386:~# echo 0 > /sys/block/vdc/queue/rotational > ^^^ Above command will hack /dev/vdc to be one SSD disk > root@debian-i386:~# echo 999999 > /proc/sys/fs/hot-age-interval > root@debian-i386:~# echo 10 > /proc/sys/fs/hot-update-interval > root@debian-i386:~# echo 10 > /proc/sys/fs/hot-reloc-interval > root@debian-i386:~# mkfs.btrfs -d single -m single -h /dev/vdb /dev/vdc -f > > WARNING! - Btrfs v0.20-rc1-254-gb0136aa-dirty IS EXPERIMENTAL > WARNING! - see http://btrfs.wiki.kernel.org before using > > [ 140.279011] device fsid c563a6dc-f192-41a9-9fe1-5a3aa01f5e4c devid 1 > transid 16 /dev/vdb > [ 140.283650] device fsid c563a6dc-f192-41a9-9fe1-5a3aa01f5e4c devid 2 > transid 16 /dev/vdc > [ 140.517089] device fsid 197d47a7-b9cd-46a8-9360-eb087b119424 devid 1 > transid 3 /dev/vdb > [ 140.550759] device fsid 197d47a7-b9cd-46a8-9360-eb087b119424 devid 1 > transid 3 /dev/vdb > [ 140.552473] device fsid c563a6dc-f192-41a9-9fe1-5a3aa01f5e4c devid 2 > transid 16 /dev/vdc > adding device /dev/vdc id 2 > [ 140.636215] device fsid 197d47a7-b9cd-46a8-9360-eb087b119424 devid 2 > transid 3 /dev/vdc > fs created label (null) on /dev/vdb > nodesize 4096 leafsize 4096 sectorsize 4096 size 14.65GB > Btrfs v0.20-rc1-254-gb0136aa-dirty > root@debian-i386:~# mount -o hot_move /dev/vdb /data2 > [ 144.855471] device fsid 197d47a7-b9cd-46a8-9360-eb087b119424 devid 1 > transid 6 /dev/vdb > [ 144.870444] btrfs: disk space caching is enabled > [ 144.904214] VFS: Turning on hot data tracking > root@debian-i386:~# dd if=/dev/zero of=/data2/test1 bs=1M count=2048 > 2048+0 records in > 2048+0 records out > 2147483648 bytes (2.1 GB) copied, 23.4948 s, 91.4 MB/s > root@debian-i386:~# df -h > Filesystem Size Used Avail Use% Mounted on > /dev/vda1 16G 13G 2.2G 86% / > tmpfs 4.8G 0 4.8G 0% /lib/init/rw > udev 10M 176K 9.9M 2% /dev > tmpfs 4.8G 0 4.8G 0% /dev/shm > /dev/vdb 15G 2.0G 13G 14% /data2 > root@debian-i386:~# btrfs fi df /data2 > Data: total=3.01GB, used=2.00GB > System: total=4.00MB, used=4.00KB > Metadata: total=8.00MB, used=2.19MB > Data_SSD: total=8.00MB, used=0.00 > root@debian-i386:~# echo 108 > /proc/sys/fs/hot-reloc-threshold > ^^^ Above command will start HOT RLEOCATE, because The data temperature is > currently 109 > root@debian-i386:~# df -h > Filesystem Size Used Avail Use% Mounted on > /dev/vda1 16G 13G 2.2G 86% / > tmpfs 4.8G 0 4.8G 0% /lib/init/rw > udev 10M 176K 9.9M 2% /dev > tmpfs 4.8G 0 4.8G 0% /dev/shm > /dev/vdb 15G 2.1G 13G 14% /data2 > root@debian-i386:~# btrfs fi df /data2 > Data: total=3.01GB, used=6.25MB > System: total=4.00MB, used=4.00KB > Metadata: total=8.00MB, used=2.26MB > Data_SSD: total=2.01GB, used=2.00GB > root@debian-i386:~# > > Zhi Yong Wu (5): > vfs: add one list_head field > btrfs: add one new block group > btrfs: add one hot relocation kthread > procfs: add three proc interfaces > btrfs: add hot relocation support > > fs/btrfs/Makefile | 3 +- > fs/btrfs/ctree.h | 26 +- > fs/btrfs/extent-tree.c | 107 +++++- > fs/btrfs/extent_io.c | 31 +- > fs/btrfs/extent_io.h | 4 + > fs/btrfs/file.c | 36 +- > fs/btrfs/hot_relocate.c | 802 > +++++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/hot_relocate.h | 48 +++ > fs/btrfs/inode-map.c | 13 +- > fs/btrfs/inode.c | 92 ++++- > fs/btrfs/ioctl.c | 23 +- > fs/btrfs/relocation.c | 14 +- > fs/btrfs/super.c | 30 +- > fs/btrfs/volumes.c | 28 +- > fs/hot_tracking.c | 1 + > include/linux/btrfs.h | 4 + > include/linux/hot_tracking.h | 1 + > kernel/sysctl.c | 22 ++ > 18 files changed, 1234 insertions(+), 51 deletions(-) > create mode 100644 fs/btrfs/hot_relocate.c > create mode 100644 fs/btrfs/hot_relocate.h > > -- > 1.7.11.7 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Regards, Zhi Yong Wu -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
