Re: port-xen/47899: xen block script does not create vnd devices when needed.

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

The following reply was made to PR port-xen/47899; it has been noted by GNATS.

From: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: port-xen-maintainer%NetBSD.org@localhost, gnats-admin%NetBSD.org@localhost,
        netbsd-bugs%NetBSD.org@localhost, 7heo%7heo.tk@localhost
Subject: Re: port-xen/47899: xen block script does not create vnd devices
 when needed.
Date: Thu, 6 Jun 2013 15:26:16 +0200

 On Thu, Jun 06, 2013 at 12:05:01PM +0000, Michael van Elst wrote:
 >  >vnconfig -l works fine for me:
 >  >ragga:/domains#vnconfig -l
 >  >vnd0: not in use
 >  >vnd1: /domains (/dev/raid1f) inode 4
 >  >vnd2: /domains (/dev/raid1f) inode 11
 >  >vnd3: /domains (/dev/raid1f) inode 12
 >  >vnd4: not in use
 >  >vnd5: not in use
 >  >vnd6: not in use
 >  >[...]
 >  >vnd29: not in use
 >  >vnd30: not in use
 >  >vnd31: not in use
 >  
 >  vnconfig will clone the driver instance when necessary, but
 >  never remove it. The first 4 instances are precreated by
 >  the driver to be compatible with earlier kernels where
 >  the driver wasn't cloning.
 
 but AFAIK vnconfig doesn't know how much instances are available in
 the kernel. It only checks if existing /dev/vnd* nodes are busy or
 not: it does a VNDIOCGET for each vnu_unit against /dev/vnd0d
 (up do cd_ndevs if I read the code properly).
 I guess cd_ndevs is increased dynamically when devices are used ...
 
 -- 
 Manuel Bouyer <bouyer%antioche.eu.org@localhost>
      NetBSD: 26 ans d'experience feront toujours la difference
 --