[linux-lvm] LVM and Network Block Device

[linux-lvm] LVM and Network Block Device

[Spam]

  Hello,

  How can I make lvm to recognize my network block devices? They are
  listed in /dev/nbd/* and I can access them fine with fdisk or dd.

  But when I try pvdisplay /dev/nbd/0 I get the following error:

  pvdisplay - ERROR "pv_read(): pv_create_name_from_kdev_t" no VALID
              physical volume "/dev/nbd/0"

  I get no errors in the logs either so I am not sure where to start.

  From what I see lvmdiskscan etc looks in /proc/partitions and never
  scans /dev/ for valid blockdevices?
  
  Thanks for any input,
  Anders

Re: [linux-lvm] LVM and Network Block Device (problem sollution)

[Spam]

  The sollution to the problem was simple. The lvm tools are hardcoded
  (from  lvm_dir_cache.c)  to  only look for specific directories when
  scaning  for  lvm disks. For network block devices lvm looks only in
  /dev/nb/*, while my Gentoo kernel created /dev/nbd/*.

  A  simple  fix was to make a link /dev/nb->/dev/nbd and it worked. I
  did not find anything about this in the howto or man-pages.

  //Anders

>   Hello,

>   How can I make lvm to recognize my network block devices? They are
>   listed in /dev/nbd/* and I can access them fine with fdisk or dd.

>   But when I try pvdisplay /dev/nbd/0 I get the following error:

>   pvdisplay - ERROR "pv_read(): pv_create_name_from_kdev_t" no VALID
>               physical volume "/dev/nbd/0"

>   I get no errors in the logs either so I am not sure where to start.

>   From what I see lvmdiskscan etc looks in /proc/partitions and never
>   scans /dev/ for valid blockdevices?
  
>   Thanks for any input,
>   Anders

Re: [linux-lvm] LVM and Network Block Device (problem sollution)

[Heinz J . Mauelshagen]

On Sat, Nov 01, 2003 at 06:27:35AM +0100, Spam wrote:
> 
>   The sollution to the problem was simple. The lvm tools are hardcoded
>   (from  lvm_dir_cache.c)  to  only look for specific directories when
>   scaning  for  lvm disks. For network block devices lvm looks only in
>   /dev/nb/*, while my Gentoo kernel created /dev/nbd/*.
> 
>   A  simple  fix was to make a link /dev/nb->/dev/nbd and it worked. I
>   did not find anything about this in the howto or man-pages.

In LVM2 we don't have hard-coded device namespace like this any more.
You can set up filters in /etc/lvm/lvm.conf, run vgscan and devices
conforming to your filters are used/excluded.

Want to give LVM2 a try ? ;)
(It is LVM1 metadata compatible)

> 
>   //Anders
> 
> >   Hello,
> 
> >   How can I make lvm to recognize my network block devices? They are
> >   listed in /dev/nbd/* and I can access them fine with fdisk or dd.
> 
> >   But when I try pvdisplay /dev/nbd/0 I get the following error:
> 
> >   pvdisplay - ERROR "pv_read(): pv_create_name_from_kdev_t" no VALID
> >               physical volume "/dev/nbd/0"
> 
> >   I get no errors in the logs either so I am not sure where to start.
> 
> >   From what I see lvmdiskscan etc looks in /proc/partitions and never
> >   scans /dev/ for valid blockdevices?
>   
> >   Thanks for any input,
> >   Anders
> 
> 
> 
> 
> 
> _______________________________________________
> 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 ***

=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

Heinz Mauelshagen                                 Sistina Software Inc.
Senior Consultant/Developer                       Am Sonnenhang 11
                                                  56242 Marienrachdorf
                                                  Germany
Mauelshagen@Sistina.com                           +49 2626 141200
                                                       FAX 924446
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-