bcache bcache

entos7的内核3.10安装后没有/sys/fs/bcache/register，升级后4.4自动出现这个目录
下载

[root@localhost mnt]# git clone https://github.com/g2p/bcache-tools.git Cloning into 'bcache-tools'... remote: Counting objects: 498, done. remote: Total 498 (delta 0), reused 0 (delta 0), pack-reused 498 Receiving objects: 100% (498/498), 106.14 KiB | 89.00 KiB/s, done. Resolving deltas: 100% (257/257), done. [root@localhost mnt]# ls bcache-tools [root@localhost mnt]# cd bcache-tools/ [root@localhost bcache-tools]# ls 69-bcache.rulesbcache.hbcache-super-show.8bcache-test.cdracutinitramfsmake-bcache.cprobe-bcache.8README bcache.cbcache-register.cbcache-super-show.cCOPYINGinitcpiomake-bcache.8Makefileprobe-bcache.c [root@localhost bcache-tools]#

编译

root@localhost bcache-tools]# make cc -O2 -Wall -g `pkg-config --cflags uuid blkid`-c -o bcache.o bcache.c cc -O2 -Wall -g `pkg-config --cflags uuid blkid`make-bcache.c bcache.o`pkg-config --libs uuid blkid` -o make-bcache cc -O2 -Wall -g `pkg-config --cflags uuid blkid`probe-bcache.c`pkg-config --libs uuid blkid` -o probe-bcache cc -O2 -Wall -g -std=gnu99bcache-super-show.c bcache.o`pkg-config --libs uuid` -o bcache-super-show cc -O2 -Wall -g-c -o bcache-register.o bcache-register.c ccbcache-register.o-o bcache-register [root@localhost bcache-tools]# make install install -m0755 make-bcache bcache-super-show/usr/sbin/ install -m0755 probe-bcache bcache-register/lib/udev/ install -m0644 69-bcache.rules/lib/udev/rules.d/ install -m0644 -- *.8 /usr/share/man/man8/ install -D -m0755 initramfs/hook/usr/share/initramfs-tools/hooks/bcache install -D -m0755 initcpio/install/usr/lib/initcpio/install/bcache install -D -m0755 dracut/module-setup.sh /lib/dracut/modules.d/90bcache/module-setup.sh

注：make时候会报blkid.h: No such file
解决 yum install libblkid-devel
因为我的sdb有数据所以要做一下这一步

[root@localhost bcache-tools]# wipefs -a /dev/sdb /dev/sdc /dev/sdb: 8 bytes were erased at offset 0x00000200 (gpt): 45 46 49 20 50 41 52 54 /dev/sdb: 8 bytes were erased at offset 0x4fffffe00 (gpt): 45 46 49 20 50 41 52 54 /dev/sdb: 2 bytes were erased at offset 0x000001fe (PMBR): 55 aa /dev/sdb: calling ioclt to re-read partition table: Success

【bcache】将sdb作为backing device，也就是HDD的盘符。

[root@localhost bcache-tools]# make-bcache -B /dev/sdb UUID:1e957d89-9d85-4011-a582-09a21a320784 Set UUID:2959a329-b79c-4488-9006-ea3b2143477a version:1 block_size:1 data_offset:16

将sdc作为cache device，也就是SSD的盘符。后面三个参数可以不要

[root@localhost bcache-tools]# make-bcache -C /dev/sdc -w4k -b1M --writeback UUID:cf262569-b799-4e8f-9d06-7a27813005c1 Set UUID:5049fd85-0353-4177-b8b5-139446e14a49 version:0 nbuckets:20480 block_size:8 bucket_size:2048 nr_in_set:1 nr_this_dev:0 first_bucket:1

注：
参数意义：

-B: 设置backing device -C: 设置cache device -w: block size (hard sector size of SSD)，默认是2K，可使用--block=4K代替 -b: bucket size，可以使用--bucket=1M代替

设备注册
格式化完成后需要完成设备的注册，使内核获取设备，可能由于内核版本的问题，在实际配置中发现，会报错，提示无法向register节点写入信息，但是并不影响使用。

[root@localhost bcache]# echo /dev/sdb > /sys/fs/bcache/register -bash: echo: write error: Invalid argument [root@localhost bcache]# echo /dev/sdc > /sys/fs/bcache/register -bash: echo: write error: Invalid argument

设备绑定
完成注册的backing device需要在使用之前绑定到bchache，否则功能无法启用。首先找到完成注册的backing device设备的

[root@localhost bcache]# ls /sys/fs/bcache/ 5049fd85-0353-4177-b8b5-139446e14a49registerregister_quiet

那么UUID= 5049fd85-0353-4177-b8b5-139446e14a49

[root@localhost bcache]# echo 5049fd85-0353-4177-b8b5-139446e14a49 > /sys/block/bcache0/bcache/attach

其中使用sdb作为backing device也就是HDD盘，sdc是SSD硬盘

[root@localhost ~]#lsblk NAMEMAJ:MIN RMSIZE RO TYPE MOUNTPOINT sdb8:16020G0 disk └─bcache0252:0020G0 disk sr011:01680M0 rom sdc8:32020G0 disk sda8:0020G0 disk ├─sda28:2019G0 part │ ├─cl-swap 253:102G0 lvm[SWAP] │ └─cl-root 253:0017G0 lvm/ └─sda18:101G0 part /boot [root@localhost ~]#

格式化

[root@localhost ~]# mkfs.ext4 /dev/bcache0

挂载

[root@localhost ~]# mount /dev/bcache0 /mnt [root@localhost ~]# df Filesystem1K-blocksUsed Available Use% Mounted on devtmpfs1002136010021360% /dev tmpfs1013960010139600% /dev/shm tmpfs1013960874410052161% /run tmpfs1013960010139600% /sys/fs/cgroup /dev/mapper/cl-root17811456 54066401240481631% / /dev/sda1103833626617677216026% /boot tmpfs20279602027960% /run/user/0 /dev/bcache02051130445080194012681% /mnt

完成其中使用sdb作为backing device，sdc是SSD硬盘

[root@localhost ~]# lsblk NAMEMAJ:MIN RMSIZE RO TYPE MOUNTPOINT sdb8:16020G0 disk └─bcache0252:0020G0 disk /mnt sr011:01680M0 rom sdc8:32020G0 disk sda8:0020G0 disk ├─sda28:2019G0 part │ ├─cl-swap 253:102G0 lvm[SWAP] │ └─cl-root 253:0017G0 lvm/ └─sda18:101G0 part /boot

bcache device状态查看

[root@localhost ~]# bcache-super-show -f /dev/sdc sb.magicok sb.first_sector8 [match] sb.csumC4ECE29EDDF45C24 [match] sb.version3 [cache device]dev.label(empty) dev.uuidcf262569-b799-4e8f-9d06-7a27813005c1 dev.sectors_per_block8 dev.sectors_per_bucket2048 dev.cache.first_sector2048 dev.cache.cache_sectors41940992 dev.cache.total_sectors41943040 dev.cache.orderedyes dev.cache.discardno dev.cache.pos0 dev.cache.replacement0 [lru]cset.uuid5049fd85-0353-4177-b8b5-139446e14a49 [root@localhost ~]# bcache-super-show -f /dev/sdb sb.magicok sb.first_sector8 [match] sb.csumADE4CA9B43970BA5 [match] sb.version1 [backing device]dev.label(empty) dev.uuid1e957d89-9d85-4011-a582-09a21a320784 dev.sectors_per_block1 dev.sectors_per_bucket1024 dev.data.first_sector16 dev.data.cache_mode0 [writethrough] dev.data.cache_state0 [detached]cset.uuid2959a329-b79c-4488-9006-ea3b2143477a [root@localhost ~]#

停用设备
注销设备：