Re: Raid5 with 2 bad drives

Mike Hardy [off-list ref] writes:

I posted a raid5 parity calculator implemented in perl a while back (a
couple weeks?) that is capable of taking your disk geometry, the RAID
LBA you're interested in, and finding the disk sector it belongs to.

I honestly don't remember if it can go the other way, but I'm not sure
why it couldn't? Its possible that bad blocks may simply be in the
parity chunk of the stripe too. Once you've got the RAID LBA you can
use the methods in the BadBlockHowto to find the file

That helps.  Although there is a typo in line 139.  See diff below.

When I know the RAID LBA how do I find out to which LV it belongs and
which sector it is in there?  But, I guess I better ask that on a LVM
list.

Matthias

--- raid5calc.orig      2005-02-23 08:26:43.721332354 -0500
+++ raid5calc   2005-02-23 08:30:12.673100526 -0500

@@ -136,7 +136,7 @@
 # Testing only -
 # Check to see if the result I got is the same as what is in the block
 open (DEVICE, "<" . $component{"device"})
-    || die "Unable to open device " . $compoent{"device"} . ": " . $! . "\n";
+    || die "Unable to open device " . $component{"device"} . ": " . $! . "\n";
 seek(DEVICE, $device_offset, 0)
     || die "Unable to seek to " . $device_offset . " device " . $xor_devices{$i} . ": " . $! . "\n";
 read(DEVICE, $data, ($sectors_per_chunk * 512))