周海漢 /文
2010.4.26
以root帳號往一臺服務器的/root傳文件時,告訴我是隻讀文件系統。搞的我一頭霧水。好好的系統怎麼變成只讀文件系統了呢?
zhouhh@zhh64:~$ scp myfile serv:.
[email protected]'s password:
scp: ./myfile: Read-only file system
登上去一看:
-bash-3.2# pwd
/root
-bash-3.2# ls
CentOS RELEASE-NOTES-en RELEASE-NOTES-nl
EULA RELEASE-NOTES-en.html RELEASE-NOTES-nl.html
GPL RELEASE-NOTES-en_US RELEASE-NOTES-pt_BR
...
-bash-3.2# cat /etc/redhat-release
CentOS release 5.2 (Final)
-bash-3.2# rm RE* -f
rm: 無法刪除 “RELEASE-NOTES-cs”: 只讀文件系統
rm: 無法刪除 “RELEASE-NOTES-cs.html”: 只讀文件系統
rm: 無法刪除 “RELEASE-NOTES-de”: 只讀文件系統
...
-bash-3.2# touch a
touch: 無法觸碰 “a”: 只讀文件系統
-bash-3.2# df -h
文件系統 容量 已用 可用 已用% 掛載點
/dev/mapper/VolGroup00-LogVol00
65G 9.8G 52G 16% /
/dev/sda1 99M 19M 75M 21% /boot
tmpfs 948M 0 948M 0% /dev/shm
CentOS_5.2_Final.iso 3.8G 3.8G 0 100% /root
CentOS_5.2_Final.iso 3.8G 3.8G 0 100% /root
奇怪,root下怎麼是兩個iso?
-bash-3.2# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
CentOS_5.2_Final.iso on /root type iso9660 (rw,loop=/dev/loop0)
CentOS_5.2_Final.iso on /root type iso9660 (rw,loop=/dev/loop1)
看到文件系統本身倒都是rw,並不是ro.
但iso文件肯定是隻讀的。
嘗試umount
-bash-3.2# umount CentOS_5.2_Final.iso
umount: /root: device is busy
設備忙,卸載不了。
網上找到umount -l參數可以處理這種情況。但man umount並沒有該參數說明。man mount說-l參數是list label。沒搞明白爲何可以卸載繁忙的設備。
嘗試一下:
-bash-3.2# umount -l CentOS_5.2_Final.iso
成功了!
-bash-3.2# umount -l CentOS_5.2_Final.iso
-bash-3.2# mount
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
-bash-3.2# cd /root
-bash-3.2# touch a
成功。
奇怪系統好好的怎麼被mount上一個iso呢?而且用法奇特。inittab上面沒有mount該文件的命令, 難道被入侵了?
看/var/log/secure並無痕跡。
後來發現系統多了一個nagios,想起密碼給過某運維同事,他來安裝nagios。估計是他進行這麼奇怪的mount了。