[linux-lvm] pvscan and vgscan

[linux-lvm] pvscan and vgscan

[Rich Turner]

how does pvscan and vgscan know what devices to scan to search for pv's
and vg's? is there a file that it uses to determine which disks to open?
it does not appear to try to open all devices when their respective
modules have not been loaded yet.

my situation is that i have volume groups on multiple scsi devices but
the scsi modules are not being loaded before vgscan is being run in the
rc.sysinit. i realize that this is a problem inherent with the
rc.sysinit and can be fixed within it. but, my question is how does
vgscan scan all devices without opening them? normally when a device is
opened all of the modules are automatically loaded, hence vgscan will
find them.

using lvm 1.0.3

Re: [linux-lvm] pvscan and vgscan

[Heinz J . Mauelshagen]

On Thu, Apr 24, 2003 at 11:16:07AM -0700, Rich Turner wrote:
> how does pvscan and vgscan know what devices to scan to search for pv's
> and vg's? is there a file that it uses to determine which disks to open?
> it does not appear to try to open all devices when their respective
> modules have not been loaded yet.

LVM1 has the tradeoff that all supported devices are hard-coded which we
changed in LVM2 to be configurable (using regular expressions).

> 
> my situation is that i have volume groups on multiple scsi devices but
> the scsi modules are not being loaded before vgscan is being run in the
> rc.sysinit. i realize that this is a problem inherent with the
> rc.sysinit and can be fixed within it. but, my question is how does
> vgscan scan all devices without opening them? normally when a device is
> opened all of the modules are automatically loaded, hence vgscan will
> find them.

It does open them. You likely have a kmod misconfiguration preventing
module load if it fails to.
> 
> using lvm 1.0.3
> 
> 
> _______________________________________________
> 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/

-- 

Regards,
Heinz    -- The LVM Guy --

*** Software bugs are stupid.
    Nevertheless it needs not so stupid people to solve them ***

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Heinz Mauelshagen                                 Sistina Software Inc.
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