Re: kern/43257: default SCSI-tape timeing parameters not selectable by kernel config

[David Holland <dholland-bugs%netbsd.org@localhost>]

The following reply was made to PR kern/43257; it has been noted by GNATS.

From: David Holland <dholland-bugs%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/43257: default SCSI-tape timeing parameters not
        selectable by kernel config
Date: Thu, 13 May 2010 18:28:22 +0000

 On Thu, May 13, 2010 at 10:25:02AM +0000, 
Wolfgang.Stukenbrock%nagler-company.com@localhost wrote:
  >  I don't know much about the possibilities of the sysctl-interface in
  >  NetBSD in respect of accessing device specific parameters. The set of
  >  devices will change over time due to connect/disconnect of devices
  >  (eg. USB or after "scsictl scan").
 
 me either, for the time being at least.
 
 I think the right way is one set of sysctls for the defaults and one
 for each attached st. However... realistically, how many people have
 multiple different tape devices in the same box? Probably one set of
 settings is good enough...
 
  >  I'm not shure if it would be a good idea to remember setting for
  >  device nodes accross disconnect/connect sequences. On the other hand,
  >  we will loose the setup for special devices after disconnect/connect
  >  if we drop them ...
 
 I doubt that can be done safely; if a new st appears, there's not
 likely to be any easy way to tell if it's the same one that
 disappeared a few minutes ago or not; also, one reason someone might
 unplug and reinsert a device is to reset things, so I'm not sure it
 would even be desirable.
 
 -- 
 David A. Holland
 dholland%netbsd.org@localhost