Re: [gentoo-user] LVM filter question

[David W Noon <dwnoon@ntlworld.com>]

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On Fri, 01 Jul 2011 22:05:12 +0200, Alex Schuster wrote about
[gentoo-user] LVM filter question:

[snip]
>     filter = [ "r|/dev/nbd.*|", "r|/dev/sdd|", "a/.*/" ]
> 
> This should reject /dev/sdd from scanning. But it doesn't, pvscan
> spins it up. Any idea why it is not being ignored?

The regular expression that precedes the one involving /dev/sdd
provides a clue: it would appear that LVM wraps the r.e. with ^ and $
so that it completes a string.

So, your r.e. should read:

   r|/dev/sdd.*|

which decodes to "reject ^/dev/sdd.*$ ".

This suppresses the scans of /dev/sdd1, /dev/sdd2, etc.

Now, you might not have any partitions on /dev/sdd, but LVM cannot
readily know that without reading the partition table, which spins up
the drive.  I guess LVM doesn't trust or, at least, depend upon udev
to supply the partition details.
-- 
Regards,

Dave  [RLU #314465]
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dwnoon@ntlworld.com (David W Noon)
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