On Tue, Jan 07, 2003 at 10:28:50AM +0100, Jan-Benedict Glaw wrote: > The first 512 byted of mentioned boot HDD where overwritten by some > Samba log! This is followed by some KB of 0x00. If you read/write directly to /dev/hda do you see any corruption? Do you see any errors for the device in the system logs? > After playing a bit with DM+LVM2, I shutted the box down to bring it to > another location, but it didn't any longer boot:-( I reinstalled the > base system (the LVs came up again with no problems:-), but rebooting > the box again, it didn't boot up again:-( I reckon it's unlikely DM/LVM2 can be causing this - not least because the device you're seeing problems on is apparently outside the DM/LVM2 system. Nevertheless, you can block LVM2 userspace from reading/writing to/from /dev/hda and its partitions by adding a filter to lvm.conf (see example.conf) e.g. "r|^/dev/hda|" and then running vgscan to apply the new filter. [Personally I recommend using a positive filter though - (a)ccept the devices you want to use with LVM2 and (r)eject everything else.] You can see what block devices the kernel device-mapper is really using by running 'dmsetup' after you have activated your LVs: For each entry in /dev/mapper, run: dmsetup deps name e.g. dmsetup deps vg0-lvol0 to get a list of major/minor numbers used. dmsetup table <name> shows you the mappings. Did you keep a complete log of the commands you ran so you can check retrospectively for typos? (e.g. "/dev/hda" where "/dev/hda2" was intended) [Always a good idea to set shell history to a big number, or (esp. on a shared box) to use 'sudo' to record all commands run as root.] If the problem is reproducible, I'd check for all occurrences of "/dev/hda" on your system (e.g. with 'rgrep') and make sure none of them have have a missing partition ID. I'd check the block device major/minors are correct & there isn't another /dev/something the same as /dev/hda & that the physical devices hda, hdb, hdc etc. haven't got reordered by mistake & the geometries & jumpers are correct. Then I'd make sure syslog was set up to log *all* messages (many distributions annoyingly throw many debug messages away by default) and run through the system startup & shutdown sequence manually, to discover at what point the sector gets corrupted, and dealing with any error messages that appear either on the screen or in the system logs. > PS: If you would like to have the floppy's contents for your own > inspection, I don't think it would help in isolation: to follow that line of investigation you need to start by working out where those 512 bytes of samba log were meant to be on your system - e.g. are they a copy of existing data, or is that sector missing from where it should be? etc. Alasdair -- agk@uk.sistina.com _______________________________________________ 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/
