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Old 06-23-2017, 08:29 PM   #1
kb2tfa
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Rescue Disk Recommendations


I was wondering if anyone has any recommendations for a rescue ISO? I see there are a few out there. I have about two dozen servers (a mix of Red Hat 5 to 7), that have to have their passwords reset. We have no access to the system. I have not been on site yet. I'm trying to get a few usbs together.
 
Old 06-23-2017, 08:41 PM   #2
ardvark71
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Quote:
Originally Posted by kb2tfa View Post
I was wondering if anyone has any recommendations for a rescue ISO?
Hi...

You can give SystemRescueCD a try.

Regards...
 
Old 06-23-2017, 09:19 PM   #3
syg00
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Any iso of the relevant architecture that will boot. Your Redhat CD/USB/whatever should suffice.
If you can't get on to the net to pull down anything else you need, you might need something more encompassing. Systemrescue should be good, although I haven't needed to use it in a while.
 
Old 06-23-2017, 10:23 PM   #4
kb2tfa
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Thank you. I wasn't sure if my CentOS Live CD would have suffice or not. I don't know if there are any RAID or specialties needed. Maybe those ISOs will work. I loaded Knoppix on a USB, and I'm playing with that on a test machine. I'll look into SystemRescueCD. Monday I go onsite, I'll close the post then stating what worked best for me.

Ron
 
Old 06-24-2017, 02:51 PM   #5
TB0ne
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Quote:
Originally Posted by kb2tfa View Post
Thank you. I wasn't sure if my CentOS Live CD would have suffice or not. I don't know if there are any RAID or specialties needed. Maybe those ISOs will work. I loaded Knoppix on a USB, and I'm playing with that on a test machine. I'll look into SystemRescueCD. Monday I go onsite, I'll close the post then stating what worked best for me.
The systemrescuecd is probably overkill. And unless you've got some old hardware with custom initrd images for RAID support, you're probably going to be able to boot from any Linux CD/DVD/USB stick and get to a 'rescue' prompt. Should just have to mount the root partition and edit the /etc/shadow file and remove everything from between the first and second colons ( and reboot. Root should have no password then.

That said...no need to bring a sledgehammer to swat a fly. If you can log in as a 'regular' user, type "cat /etc/group | grep -i wheel" in at a terminal prompt. If any users are in that group, you *MAY* be able to run "sudo -s" (or at least "sudo passwd root") as one of those 'regular' users, and get the password changed. You may also want to try these:
https://access.redhat.com/documentat...ot-passwd.html
https://www.tecmint.com/reset-forgot...os-and-fedora/

While it's for RHEL 4/CentOS, it *MAY* work on newer versions, since you're basically using grub to get to single-user mode.
 
Old 06-24-2017, 05:29 PM   #6
jefro
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Also Centos info.

https://wiki.centos.org/TipsAndTricks/ResetRootPassword

RH also offers support for their products. It may be wise to consider paying for it.

Last edited by jefro; 06-24-2017 at 05:30 PM.
 
Old 06-24-2017, 08:53 PM   #7
!!!
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init=/bin/bash maybe. (pics)
 
Old 06-25-2017, 06:41 PM   #8
AwesomeMachine
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Yo7u can boot from any live CD, chroot to the / of the installation, and run the passwd command to change the password.
 
Old 06-25-2017, 07:43 PM   #9
kb2tfa
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I think I'm leaning on chroot because I have no info about the system. Changing the root password right away may have unintended results. There could be a script of something running off of root. I am thinking of chroot to create an elevated user to get a window into the system first. There are upwards of two dozen servers that we have no control over. The previous admin is no more, and nothing is documented. I need to keep the damage and downtime as minimal as possible. I may just try to drop into initramfs via grub to chroot. If that doesn't work, I'll boot a CD.
 
  


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