tried to start an uml make it read only. so i start it with         ./linux mem=256M  ubd0r=/root/rootfs
it reports that :

Setting hostname rhel4:  [  OK  ]
Checking root filesystem
[/sbin/fsck.ext3 (1) -- /] fsck.ext3 -a /dev/ubd/0
fsck.ext3: Read-only file system while trying to open /dev/ubd/0
Disk write-protected; use the -n option to do a read-only
check of the device.

*** An error occurred during the file system check.
*** Dropping you to a shell; the system will reboot
*** when you leave the shell.
Give root password for maintenance
(or type Control-D to continue):

i have tried that : 
before start uml , use e2fsck rootfs  , start it  hangs there.
when hangs there , typed root password , and run fsck . report an error , read only system, can't do this , advise to run fsck with -n , after that reboot , always hangs there .
so  any advices ? thank you.

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