Hi all

I hope I'm on topic.

There's a way to run fsck on root filesystem without rebooting the system?

I cannot run fsck on a mounted filesystem and (obviously) I can't umount it while the system is running.

I tried remounting it in read-only mode like seen on google search but I get a "busy" error and I can't do it.

The filesystem is an ext3

I want to fsck it because i was low on disk space ( 100 mb free ), so I deleted 400 mb of crap and I'm still with only 100 mb free.

And I can't find this crap, with a du -sh * I can't find nothing strange .. like clusters wasn't signed as free ..

Why....wont you reboot?
uptime?
Please...just reboot...see if you have an empty drive now.If not...reboot into recovery mode and run fsck again with other parameters to see if theres a problem and exactly what it is.
If you run chrootkit.....run it again to do some kind of comparison.
I like rkhunter...also I use tripwire....things like these help let you spot a rootkit which if your space problem still exists is exactly what you have.
If a rootkit is indeed on your system....zero your harddrive and reinstall.

The real reason 'coz I won't reboot is for exercise .. I want to solve every problem without rebooting.

The problem is on my home server, and I don't run rootkit detection SW.

At this point I hope that a fsck on reboot will fix all .. and that no rootkit are on my system ..

you'll have to "unload" the filesystem before you can remount it read-only ( you'll have to unmount any filesystems which are mounted on top of your filesystem, like proc)