Server Recovery

[BeeRich]

Hi folks. I'm having a boot problem. I can't seem to get CentOS 7.7 booted up.

The BIOS on this Intel i3 box is horrible. Drives show up though. I have a PCIe M.2 SSD as well, with AlmaLinux installed on it. When I pull that out, the BIOS shows me that it's still available. So the BIOS is a culprit in all this.

I have a drive with CentOS on it. It's visible. I've not changed any drives, not renamed them, not changed any IDs as well.

Any insight appreciated. I'm currently trying to get an external USB drive formatted with the full CentOS 7 image on it, so I can troubleshoot from that.

Cheers

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[BeeRich]

Well it seems the partitions are bad. "Couldn't find valid filesystem superblock".

Not sure what to do now. I can't unmount it, cannot get xfs_repair to work on /dev/sda1

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sudo unmount /dev/sda1						# doesn't work
$ xfs_repair -n /dev/sda1						# repair partitions
Superblock has unknown compat/rocompat/incompat features
Using a more recent xfs_repair is rcommended.
Found unsupported filesystem features.  Exiting now.
$ e2fsck -fv /dev/sda1
ext2fs_open2: Bad magic number in super-block
Superblock invalid, trying backup blocks...
Bad magic number in super-block while trying to open /dev/sda1

# Bad superblock						# https://www.cyberciti.biz/faq/recover-bad-superblock-from-corrupted-partition/
$ dumpe2fs /dev/sda1 | grep superblock
Bad magic number in super-block while trying to open /dev/sda1.  couldn't find valid filesystem superblock

[tunk]

Does smartctl -a /dev/sda show any problems?

[TrevorH]

$ xfs_repair -n /dev/sda1 # repair partitions
Superblock has unknown compat/rocompat/incompat features
Using a more recent xfs_repair is rcommended.

As I read that, it seems to be saying that it is an xfs filesystem but the version of xfs supported by the system you have booted is not new enough to be able to repair it as it has features enabled that your current xfs_repair does not know about. Did you boot the same version of the o/s as the one that is installed?

[BeeRich]

Does smartctl -a /dev/sda show any problems?

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smartctl not found

[BeeRich]

As I read that, it seems to be saying that it is an xfs filesystem but the version of xfs supported by the system you have booted is not new enough to be able to repair it as it has features enabled that your current xfs_repair does not know about. Did you boot the same version of the o/s as the one that is installed?

7.8.2003 is the installed version. I am using 2009 on my troubleshooting drive. Wouldn't 2009 have the backwards compatability?

[BeeRich]

Just found this: https://docs.centos.org/en-US/centos/in ... scue_Mode/

Unable to Boot into CentOS
This problem is often caused by the installation of another operating system after you have installed CentOS. Some other operating systems assume that you have no other operating system(s) on your computer. They overwrite the Master Boot Record (MBR) that originally contained the GRUB2 boot loader. If the boot loader is overwritten in this manner, you cannot boot CentOS unless you can boot into installation program rescue mode and reconfigure the boot loader.

So I'm chasing this route.

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$ /sbin/grub2-install /dev/sda
<reboot>

This brings me to a prompt:

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grub>

How do I move forward? /etc/fstab is now original again. Shouldn't it just load the OS properly?