mouss wrote:
Dan Bongert wrote:
mouss wrote:
Dan Bongert wrote:
Hello all:
I have a couple CentOS 4 servers (all up-to-date) that are having strange command failures. I first noticed this with a perl script that uses lots of system calls.
thoth(66) /tmp> uname -a Linux thoth.ssc.wisc.edu 2.6.9-67.0.7.ELsmp #1 SMP Sat Mar 15 06:54:55 EDT 2008 i686 i686 i386 GNU/Linux
Nothing in either dmesg or /var/log/messages seems to indicate any problems. It also doesn't seem to matter what the command is -- ls is the quickest test, but sshd will sometimes to fail to spawn children, etc. There aren't a large amount of processes on the machine either -- only 122 at the moment.
Has anyone seen this behavior before? Have I been hit with some sort of cunning rootkit? This machine shouldn't be publicly accessible; it's behind our firewall.
where is /tmp mounted? is this an external disk (usb, ...)? is it an nfs mount?
It's a local disk:
thoth(97) /tmp> df -h . Filesystem Size Used Avail Use% Mounted on /dev/md4 16G 77M 15G 1% /tmp
Though 'ls' was just an example -- just about any program will fail. The 'w' command will fail too:
maybe check your PATH. try $ /bin/ls
Ok, here's a heck of a thing. When I run 'ls' using the full path (and also when I unalias it -- I have 'ls' aliased to 'ls -F --color'), 'ls' no longer fails.
However, my other test case, 'w', still fails.
(and these are all test cases because I noticed a nightly job with a lot of system() calls was failing).