Date: Mon, 11 Nov 2013 23:32:43 +0800 From: Erich Dollansky <erich@alogt.com> To: Warren Block <wblock@wonkity.com> Cc: freebsd-geom@freebsd.org Subject: Re: documentation of GEOM data structures needed Message-ID: <20131111233243.0ee485be@X220.ovitrap.com> In-Reply-To: <alpine.BSF.2.00.1311110812470.99300@wonkity.com> References: <20131111162400.0bc7dfef@X220.ovitrap.com> <alpine.BSF.2.00.1311110812470.99300@wonkity.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi, On Mon, 11 Nov 2013 08:19:57 -0700 (MST) Warren Block <wblock@wonkity.com> wrote: > On Mon, 11 Nov 2013, Erich Dollansky wrote: > > > I would need a documentation of the GEOM data structure. A disk got > > damages in a strange way during the process of backing up data. It > > was partitioned with gpart as all my disks using the MBR schema. > > When creating the backup, the system crashed. The disk was not > > usable anymore. I found out that the MBR was overwritten before the > > backup was started while the beginning of the first partition seems > > to be ok. > > MBR does not have any specific GEOM structure. It's just a standard > MBR: http://en.wikipedia.org/wiki/Master_boot_record this I knew. It points then to the container for the FreeBSD slices. > > See the end of the mdconfig(8) man page for an example of using it > and gnop(8) to skip over an arbitrary length of data at the start of > a disk. > I did not tell you the other effect I have with this disk. It boots until FreeBSD wants to mount /. So, the loaders somehow find the kernel etc. All seems to be there except the proper entries in the data structures defining the container and the individual partitions. > With that and file -s, you can attempt to find mountable filesystems > on the whole disk. A script would be the fastest way. The first one > should be relatively easy. After that, guessing approximate > locations would speed it up a lot. This is the alternative if my assumptions are wrong. Erich
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20131111233243.0ee485be>