Linux raw device 생성 (Character device)

Linux raw device 생성

character device로 전환하여 OS의 disk block buffer cache를 거치지 않고 바로 I/O수행

raw device 생성

- 생성
# raw /dev/raw/raw99 /dev/testvg/testlv 
/dev/raw/raw99:  bound to major 253, minor 2

- 확인
# raw -qa
/dev/raw/raw99:  bound to major 253, minor 2

# ls -l /dev/raw
total 0
crw-rw----. 1 root disk 162, 99 Feb 19 09:15 raw99
crw-rw----. 1 root disk 162,  0 Feb 19 09:05 rawctl

raw device 삭제

# raw /dev/raw/raw99 0 0

raw deivce 생성 permanent

RedHat 링크

- udev rule 생성 // vg, lv, owner, group, mode는 상황에 따라 변경
# cat /etc/udev/rules.d/60-raw.rules 
ACTION=="add|change"

ENV{DM_VG_NAME}=="testvg", ENV{DM_LV_NAME}=="testlv",RUN+="/usr/bin/raw /dev/raw/raw1 %N"
KERNEL=="raw*",OWNER="root",GROUP="disk",MODE="0660"


# udevadm control --reload-rules
# udevadm trigger --type=devices --action=add

- 확인
# raw -qa
/dev/raw/raw1:  bound to major 253, minor 2