混合存储磁盘加速

[tiancheng91]

背景: arm小主机外置tf卡存储性能太差, 与内置emmc/memdisk一起构建混合存储加速. 方案: lvm-cache 结论: lvm-cache不能放在ramdisk上,重启会丢失数据. lvm-cache配置太麻烦了, 换用juicefs缓存

lvm配置

新建内存块设备

dd if=/dev/zero of=/dev/shm/memcache bs=3M count=100
losetup /dev/loop0 /dev/shm/memcache
losetup -d /dev/loop0

lvm-volume

# Create volume
pvcreate /dev/sdb
vgcreate vg /dev/sdb
lvcreate --size 400g --name lv vg
mkfs.xfs /dev/vg/lv
mkdir /mnt/lv
mount /dev/vg/lv /mnt/lv
# Write test
dd bs=1M if=/dev/zero of=/mnt/lv/zero count=10000

lvm-cache

# Create a RAM disk
modprobe brd rd_nr=1 rd_size=4585760 max_part=0
pvcreate /dev/ram0
vgextend vg /dev/ram0
# Create a cache
lvcreate -L 300M -n cache_meta vg /dev/ram0
lvcreate -L 4G -n cache_vol vg /dev/ram0
lvconvert –type cache-pool –poolmetadata vg/cache_meta –cachemode=writeback vg/cache_vol -y
# Add cache to a LV
lvconvert –type cache –cachepool vg/cache_vol vg/lv
# Write test
dd bs=1M if=/dev/zero of=/mnt/lv/zero2 count=10000
# Crash test
echo 'c' > /proc/sysrq-trigger