UNIX for Advanced & Expert Users

hi,
1. When i am deleting file in the linux machine i am getting below error message.
rm text.fil
rm: remove regular file `text.fil'? y
rm: cannot remove `text.fil': Read-only file system
From su also i tried i am getting same error message.

2. Some times the file permissions and user name and group as displayed as '?'

After rebooting the server the issue can be resolved but after some time same issue occuring again. kindly help me.

It looks like you're suffering from disk corruption. The machine is sensibly refusing to write to a malfunctioning disk.

There may be messages at the bottom of 'dmesg | less' which state exactly what provoked it into setting the filesystem read-only.

Filesystem corruption like this is very abnormal and frequently irrecoverable. It may be caused by the disk itself(try ide_smart to see if your drive's failing any internal diagnostics), the drive cable(unlikely), the disk controller, the disk controller driver, or failing memory inside the server itself(test with a memtest86 boot cd).

But first: Back up your files now while you still can!