Thursday 23 February 2012

Forget the root password on SunBlade


I inadvertadly changed my root password on my SunBlade100 test computer.
Is there any way I can figure it out without having to reconfigure the whole OS.


Answer :
First ,if you know what file system is used is Solaris zfs, then you need a live distro
or rescue disk for Solaris. When you run off a live distro or rescue disk, the root
filesystem exists in memory.
Look at the output of the “mount” command by itself to see if the hard disk partitons
are mounted. If not, you will want to mount the root partition somewhere such as mount.
There are a lot of ifs here, such as whether the kernel your live distro or rescue disk
uses is able to mount the partition rw. Solaris will use different device names for
partitions.
There are in /dev/ and probably end in p1 for the first partition, p2 for the second, etc.
If your disk has the fdisk program (I don’t know if solaris has its own version of this
program), running “fdisk -l” will list the partitions. You need to use the mount
command to mount the partition that has the /etc directory.
It should be on the root partition. I can’t see anyone wanting to mount it anywhere else.
Look at the /etc/passwd file. If there is a line like: “root:x:0:0:root:/root:/bin/bash” with
the second field of “x”, then the system uses shadow passwords. The password hash
is in /etc/shadow. Otherwise, you may see a lot of random characters between the first
and second colons. Look at the /etc/shadow file at the entry starting with “root”:
root:$2a$13$gf4PslessRtZJ33IgSq33eKyS33TYJES3dPEz57dCLp556Qpabde3:14087::::::
Delete the characters between the two colons to zero the root password.
This means you can reboot and login as root with no password. Then run “passwd”
as root to change the root password. If you have a system that doesn’t allow a null
password for root, this mean that you will not be able to login after zeroing out
the password hash in /etc/shadow.
In this case you have to copy the hash from the regular users entry and copied it for
root’s. That will allow you to log in as root using the regular user’s password and then
to run “passwd” to change it.

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