Tue 31st Jan 2012 @ 23:08 2012: rm -rf /

It is commonly said that Solaris 10 will not allow you to issue a rm -rf / command. Few get to try it, but it was being discussed in the office today, so I thought I'd try it on a virtual machine.

The classic rm -rf / gets the message "rm of / is not allowed" and a return code of 2. Some variations get the same, whilst others (such as cd /; rm -rf .) get no message, a return code of zero, but nothing happens. Here is a transcript:

$ ssh sunflare
Password:
Last login: Tue Jan 31 21:38:05 2012 from goldie
Oracle Corporation SunOS 5.10 Generic Patch January 2005
steve@sunflare:~$ su -
Password:
Oracle Corporation SunOS 5.10 Generic Patch January 2005
# bash
root@sunflare:/# df -h
Filesystem size used avail capacity Mounted on
/dev/md/dsk/d10 9.6G 3.6G 5.9G 38% /
/devices 0K 0K 0K 0% /devices
ctfs 0K 0K 0K 0% /system/contract
proc 0K 0K 0K 0% /proc
mnttab 0K 0K 0K 0% /etc/mnttab
swap 2.1G 992K 2.1G 1% /etc/svc/volatile
objfs 0K 0K 0K 0% /system/object
sharefs 0K 0K 0K 0% /etc/dfs/sharetab
fd 0K 0K 0K 0% /dev/fd
swap 2.1G 72K 2.1G 1% /tmp
swap 2.1G 32K 2.1G 1% /var/run
/dev/md/dsk/d60 4.6G 4.7M 4.6G 1% /export/home
root@sunflare:/# rm -rf /
rm of / is not allowed
root@sunflare:/# echo $?
2
root@sunflare:/# cd /usr
root@sunflare:/usr# rm -rf ../
rm of / is not allowed
root@sunflare:/usr# cd /tmp
root@sunflare:/tmp# rm -rf ../
rm of / is not allowed
root@sunflare:/tmp# cd /usr/sfw/bin
root@sunflare:/usr/sfw/bin# rm -rf ../../..
root@sunflare:/usr/sfw/bin# cd /
root@sunflare:/# rm -rf .
root@sunflare:/# echo $?
0
root@sunflare:/# pwd
/
root@sunflare:/# df -h .
Filesystem size used avail capacity Mounted on
/dev/md/dsk/d10 9.6G 3.6G 5.9G 38% /
root@sunflare:/# cd /dev
root@sunflare:/dev# rm -rf ../tmp/../
rm of / is not allowed
root@sunflare:/dev# rm -rf ../tmp/..
root@sunflare:/dev# exit
steve@sunflare:~$ logout
Connection to sunflare closed.
$