Ako se particija javi kao RO

Dakle ako mount-ujete neku od particija na storidžu (kroz ISCSI), i ona se (npr zbog prekida u mreži) javi kao read only, evo šta su simptomi i šta sve može da se uradi :
Simptomi problema za unmount particije :
# touch test
touch: cannot touch `test’: Read-only file system
# umount /Problem2/
umount: /Problem2: device is busy
# umount -f /Problem2/
umount2: Device or resource busy
umount: /Problem2: device is busy
Rešenje za unmount particije :
Dakle kako na kraju unmount-ovati /Problem2 :
# umount -l /Problem2/
Šta sve pogledati za mount problem :
A ako pokušamo sa standardnim podizanjem posle ovoga, a neće :
# mount -a
mount: /dev/problem2 already mounted or /Problem2 busy
Probati uz definisani tip OS-a :
# mount -t ext3 /dev/problem2 /Problem2/
mount: /dev/problem2 already mounted or /Problem2/ busy
Probati sa verbose, da se vidi maksimalna količina podataka :
# mount -v /dev/problem2 /Problem2/
mount: you didn’t specify a filesystem type for /dev/problem2
I will try type ext3
mount: /dev/problem2 already mounted or /Problem2/ busy
Da se vidi ko sve pristupa folderu :
# fuser -vm /Problem2
USER PID ACCESS COMMAND
/EMChome root 1 .rce. init
root 2 .rc.. migration/0
root 3 .rc.. ksoftirqd/0
root 4 .rc.. migration/1
root 5 .rc.. ksoftirqd/1
…..
Kako pronaći procese koji pristupaju mount point-u, pa to možda pravi probleme :
# lsof |grep /Problem2
Odnosno :
# lsof |grep /dev/problem2
Videti šta je sve mount-ovano (pošto na storidžu imam dva LUN-a):
# mount|grep problem
/dev/problem1 on /Problem1 type ext3 (rw,_netdev)
Dakle ovo je OK, ali moj nesrećni /Problem2 tj /dev/problem2 se ne javlja nigde…..
Izlistati sve particije, pa videti jel se tu javlja neki problem :
# fdisk -l
Disk /dev/sda: 249.9 GB, 249965314048 bytes
255 heads, 63 sectors/track, 30389 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 1 25 200781 83 Linux
/dev/sda2 26 19147 153597465 83 Linux
/dev/sda3 19148 24246 40957717+ 83 Linux
/dev/sda4 24247 30389 49343647+ 5 Extended
/dev/sda5 24247 29345 40957686 83 Linux
/dev/sda6 29346 29600 2048256 82 Linux swap
…..
Proveriti da li upis postoji u fajlu /etc/mtab, ako postoji, ukloniti ga, i probati klasičan mount ponovo :
# less /etc/mtab|grep problem
/dev/problem1 /Problem1 ext3 rw,_netdev 0 0

Krajnje rešenje : restartovati ceo server 😉