How to locate a bad block on disk reported by SMART?

[Mariano Draghi]

Hi list,

I'm getting this e-mail daily, since a few days:

> The following warning/error was logged by the smartd daemon:
> 
> Device: /dev/hda, 1 Currently unreadable (pending) sectors
> 
> For details see host's SYSLOG (default: /var/log/messages).
> 
> You can also use the smartctl utility for further investigation.
> No additional email messages about this problem will be sent.

 From /var/log/messages, I can read this:
> Feb  1 00:20:38 home smartd[3612]: Device: /dev/hda, 1 Currently unreadable (pending) sectors

... and from and early SYSLOG (named messages.1), this:
> Jan 25 19:11:28 home kernel: hda: dma_intr: status=0x51 { DriveReady SeekComplete Error }
> Jan 25 19:11:28 home kernel: hda: dma_intr: error=0x40 { UncorrectableError }, LBAsect=33336872, sector=33336872
> Jan 25 19:11:28 home kernel: ide: failed opcode was: unknown
> Jan 25 19:11:28 home kernel: end_request: I/O error, dev hda, sector 33336872
> Jan 25 19:11:29 home kernel: hda: dma_intr: status=0x51 { DriveReady SeekComplete Error }
> Jan 25 19:11:29 home kernel: hda: dma_intr: error=0x40 { UncorrectableError }, LBAsect=33336872, sector=33336872
> Jan 25 19:11:29 home kernel: ide: failed opcode was: unknown
> Jan 25 19:11:29 home kernel: end_request: I/O error, dev hda, sector 33336872
> Jan 25 19:11:29 home kernel: Buffer I/O error on device dm-0, logical block 1581163

I remember getting and error that day doing a massive copy of a bounch
of files from one filesystem to another. But I moved so many things that
I don't know for sure which filesystem has the bad block.

I've been trying Google to find how to deal with this issue, and I've
found this document:
http://smartmontools.sourceforge.net/BadBlockHowTo.txt
which explains how to find the sector, the i-node and the file, and how
to write zeros to it (to force the hardware to mark the sector as bad).
But I couldn't figure out how to find which is the faulty partition.
Besides, My root and home partitions are on LVM, and I don't want to
mess up any metadata... I mean, I don't know if the low level approach
described there applies flowesly to a partition into a LVM volume.

Could anybody help me sorting this out?

TIA,

-- 
Mariano