On Thursday 15 May 2003 03:14, Ewen McNeill wrote: > In message <20030515055917.GB19045@www.13thfloor.at>, Herbert Poetzl writes: > >On Wed, May 14, 2003 at 10:41:37AM -0500, B. J. Zolp wrote: > >> Should I be able to dd (without reading the bad sectors) the failing > >> drive (assuming it spins up and reads all the good sectors) to the > >> replacement drive, then run fsck on the unmounted volume and then mount > >> the volume with minimal data loss? > > > >I guess, this should work ... but make sure, that > >you do the copy operation on another system, otherwise > >the LVM stuff could/will be irritated by two diffent > >disks with the same signature (after copying over) > > Other things to consider: > > - make sure you do the dd with an option to replace unreadable sectors > with blank sectors (otherwise nothing will be written out for the > unreadable sectors, causing everything to be "out of alignment" after > the first bad block) > I plan on using the noerror switch for dd, what else would I need to use to make sure it replaces with blank sectors. I could not find anything in info dd or man dd. > - do the copy in single user mode, preferable booted in such a way that > the LVM isn't active (or on another system as suggested above) > > - it'll take longer but consider copying in sector-by-sector chunks, as > it'll reduce the amount skipped (eg, bs=512) > great idea > - you may want to map which logical volumes, and which files on those > volumes, are affected by the bad sectors before you start, so you know > which files you'll lose (you could use something like "badblocks" -- > in _read_only_ mode!! -- to identify the affected blocks) > > But aside from that, given an identical sized replacement disk and/or > replacement partition, I'd guess it should, in theory, work. I've seen > similar things done with other systems with logical volume managers > (eg, HP/UX 10.20) reasonably successfully (we ended up restoring much > of the data from backup anyway to get a consistent database snapshot, > but it did save a bunch of volume reconstruction time, etc). > > Ewen > > _______________________________________________ > linux-lvm mailing list > linux-lvm@sistina.com > http://lists.sistina.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
