On 16 June 2010 16:26, Daniel Pittman <[email protected]> wrote: > LVM, by default, is a boring old linear mapping, so he probably has two disks > worth of data ... starting a third (or whatever) of the way through the file > system. So, no superblock on whatever.
Why no superblock? The ext3 filesystem (and I guess the most usual suspects) write multiple copies of the superblock across the entire data partition just for such cases. It's tricky to find them (the only way I saw documented was to execute "mke2fs -n" on a partition with identical size and record the block numbers it emits. I'm sure there must be ways to identify superblocks by their magic numbers somehow) but the data should be there. > >> I can think of what I'd write to try and recover -something- but it'd >> involve writing a whole lot of rather hairy looking filesystem-scraping >> code. I'm sure there are tools to do this kind of partial data recovery >> but they're bound to be -very- expensive. > > The 'testdisk' package available in Debian, and fully OSS, can do quite a lot > of data recovery without a file system. It just block-scrapes the device. Right. I used it a couple of times and can tell that without file names it's a chore to wade through all the data and try to find which is important and which isn't. "file" is handy to do that (as in, e.g., run "find ...| xargs file | grep ..." and move all files of each type to their own directories). Cheers, --Amos -- SLUG - Sydney Linux User's Group Mailing List - http://slug.org.au/ Subscription info and FAQs: http://slug.org.au/faq/mailinglists.html
