Hi All,

this is very urgent.

i logged in my RHEL linux machine via PUTTY .as say XYZ user.

then i

typed followinfg command

sudo su -



and then i put password for XYZ user.



then

inside home directory i created directory say test_directory1. and inside test_directory1 another directory say "new_testdirectory" is created.



then i disconnected from PUTTY.



then i again login via PUTTY as XZY again

and again typed sudo su -



and this time i first navigate to test_directory1

when i put command here : ls



it showed me "new_directory" as result.





now here i did one mistake.. I WANTED TO DELETE THIS "new_directory" so i should type following command



rm -rf new_direcotory /





BUT

MISTAKE I DID IS



rm -rf /



this / made difference..



now problem is via PUTTY when i login it is now allowing me to login as XYZ user...

so i found out the way to login by coping bin folder from another RHEL machine to my this RHEL machine... so now i can login via PUTTY.



BUT NOT ABLE TO DO "sudo su - "



MY QUESTION IS

1) how to FIX THIS sudo su - login problem

2) when i do rm -rf / what all files, users, daemons get deleted ? AND HOW TO ROLLBACK THIS ALL ?

Just restore from your backup.

you can see the deleted files with testdisk, though if you want to recover files, try not to write to the disk

Everything on the machine gets deleted. There is no real roll back for this deletion. You may be able to recover the system using Testdisk, but I assume that you have not immediately powered down the machine, so that writes to the disk did already happen. In this case it is unlikely to recover the system to a known good state.

So your fastest and best options to recover are:
- restore your backup. If you don't have one now you know why you should make backups.
- install from scratch

Your best bet at this point is a fresh reinstall. So I hope you have a vps for easy reinstall or the server is local to you.

1 members found this post helpful.

Just a tip when you get up and running. I have a healthy paranoid with dangerous commands such as rm -rf or dd.

I type the command without the sudo in front of it. I then go back to the beginning of the line and add sudo after verifying it's correct. It probably sounds like extra pointless work, but I've never accidently deleted my root partition either

Not a bad Idea. you could always use the -I or -i option as well. If heard where somepeople create shortcuts in there bash files where anytime they use rm it adds the -I or -i Option.

Either way it all comes down to paying attention and understand and verify what you do before you do it. As some actions are not reversible.

And don't worry too much about it.

Everybody does something like this at least once.

I reinstalled my first UNIX system because I did an fsck on a partition... unfortunately it happened to be the diagnostic partition that spanned the entire drive. And wiped out every file on all partitions.

Practically a Right-of-Passage.

I had a C program once, running as root, where I passed a pointer to a proc and that pointer was supposed to be pointing to a PID that the proc would then kill. This was a long time ago, SystemV I believe, and back in those days you could read the null pointer (I beleve most/all OS'es now-a-days balk at this). But back then it was a legal, albeit stupid, thing to do. Anyway, upon debug after-the-fact, I learned that my null pointer apparently (and umfortunately!) was pointing to "1" when I passed it to that proc.

It was a very ungraceful, but lightening quick, system shutdown! Believe it or not, the system came right back up after that (I believe an fsck may have been involved though).

I know I've done it. It was back in the RedHat 7 days (2000/2001) when I was first learning Linux. I THOUGHT that I was in a useless directory in root's home, and ran an "rm -fr *". Turns out I was actually in /. I Ctrl+C'd as soon as I realized it, but it was too late. After about 6 hours of trying to fix the system, I threw in the towel and reinstalled the OS.

OP - I hate to say it, but this is one of those mistakes that you rarely come back from. I bet you'll never do it again though!

As per above post
Even at work, if you're a SysAdmin and never wiped out a major dir, you're not working hard enough.
I bet you do proper backups from now on though ...

Once I was trying to wipe my MBR with dd. I wasn't thinking and set the count to 512 bytes instead if 446, wiping out my partition table.

I had something similar with an USB flash drive. I wanted to write an image to it using dd, unfortunately I wrote the image to the harddisk of my work PC. Luckily, my boss just laughed and I had to re-install the machine, this time making a proper backup.

typos happen
back up data

after a few years you start to make less of the normal everyday " stupid human errors ", BUT they still happen .