[lug] is there a way to get partition table on running system?

[stimits at comcast.net]

Not that I can do anything to actually help, but I do wonder how things have changed with UEFI and alternative boot systems from the original 512 byte MBR. See:
http://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface
http://en.wikipedia.org/wiki/GUID_Partition_Table
https://wiki.archlinux.org/index.php/Master_Boot_Record

It used to be that if you had those first 512 bytes backed up with dd you could restore it...provided nothing had changed on the disk since then (possibly changes to the disk in places not at the boundary of partitions would be tolerated). UEFI and disk labels seem to have changed things. Seems like back in the pure MBR scheme with 512 bytes there was a backup or shadow MBR which the disk itself could use if it had to remap due to a bad block, though I don't recall where that was.

The latter of the above web links indicates that the actual partition record starts after byte 446 of the 512 bytes...part of the reason why only 4 primary partitions could be used.

----- Original Message -----
From: Bear Giles 
To: Boulder (Colorado) Linux Users Group -- General Mailing List 
Sent: Fri, 08 Nov 2013 13:32:44 -0000 (UTC)
Subject: [lug] is there a way to get partition table on running system?

Is there a way to get a partition table on a running system? I had a brain fart and zeroed out the start of my HD so it (and an unknown portion of my /boot partition) are gone. I know I can recover from the latter by reinstalling the kernel package but I don't know if the partition table is cached.


In the past I've remembered to cache my own copy but I forgot to do it when installing this system.

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