[Nbd] probs with nbd-client 2.9.13 running on centos 5.4 (64bit)

["Daniel Schwager" <Daniel.Schwager@...207...>]

Hi Wouter,

we try to install nbd-client on an new, vanilla Centos5.4-64bit
and got a different behavior on 2 points against a FC9-64bit
installation:

a) running without using "-nofork" create TWO processes of  nbd-client:
		2953 ?        Ss     0:00 /opt/nbd/usr/sbin/nbd-client
storage13.dev.xx.de 1024 /dev/nbd0
		2954 ?        S      0:00 /opt/nbd/usr/sbin/nbd-client
storage13.dev.xx.de 1024 /dev/nbd0

   running the same command on FC9 forks only ONE nbd-client process and
one nbd0 process:
		20655 ?        S      0:00 /opt/nbd/usr/sbin/nbd-client
storage13.dev.xx.de 1024 /dev/nbd0
		20656 ?        S<     0:00 [nbd0]

   Is this a problem ?


b) Running nbc-client with -c to get the PID fails on centos 
   because of missing file /sys/block/nbd0/pid:

	# simple "check" if connected ...
	kvm02:/opt/nbd# less  /dev/nbd0
	/dev/nbd0 is not a regular file (use -f to see it)
	
	kvm02:/opt/nbd# /opt/nbd/usr/sbin/nbd-client -c /dev/nbd0
	kvm02:/opt/nbd# echo $?
	1

	# Start strace
	kvm02:/opt/nbd# strace /opt/nbd/usr/sbin/nbd-client -c /dev/nbd0

	execve("/opt/nbd/usr/sbin/nbd-client",
["/opt/nbd/usr/sbin/nbd-client", "-c", "/dev/nbd0"], [/* 26 vars */]) =
0
		.....
	open("/sys/block/nbd0/pid", O_RDONLY)   = -1 ENOENT (No such
file or directory)
	exit_group(1)                           = ?
	kvm02:/opt/nbd#

	# Not PID file available:
	kvm02:/opt/nbd# find /sys/block/nbd0 | grep pid | wc -l
	0

	# hmm ....
	kvm02:/opt/nbd# find /sys/block/nbd0
	/sys/block/nbd0
	/sys/block/nbd0/queue
	/sys/block/nbd0/queue/iosched
	/sys/block/nbd0/queue/iosched/slice_idle
	/sys/block/nbd0/queue/iosched/slice_async_rq
	/sys/block/nbd0/queue/iosched/slice_async
	/sys/block/nbd0/queue/iosched/slice_sync
	/sys/block/nbd0/queue/iosched/back_seek_penalty
	/sys/block/nbd0/queue/iosched/back_seek_max
	/sys/block/nbd0/queue/iosched/fifo_expire_async
	/sys/block/nbd0/queue/iosched/fifo_expire_sync
	/sys/block/nbd0/queue/iosched/queued
	/sys/block/nbd0/queue/iosched/quantum
	/sys/block/nbd0/queue/iostats
	/sys/block/nbd0/queue/scheduler
	/sys/block/nbd0/queue/max_sectors_kb
	/sys/block/nbd0/queue/max_hw_sectors_kb
	/sys/block/nbd0/queue/read_ahead_kb
	/sys/block/nbd0/queue/nr_requests
	/sys/block/nbd0/slaves
	/sys/block/nbd0/holders
	/sys/block/nbd0/subsystem
	/sys/block/nbd0/stat
	/sys/block/nbd0/size
	/sys/block/nbd0/removable
	/sys/block/nbd0/range
	/sys/block/nbd0/dev
	/sys/block/nbd0/uevent
	kvm02:/opt/nbd#

	# Some infos ...
	kvm02:/opt/nbd# uname -a
	Linux kvm02.dev.xx.de 2.6.18-164.2.1.el5 #1 SMP Wed Sep 30
12:52:46 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux
	kvm02:/opt/nbd# rpm -qa | grep udev
	udev-095-14.21.el5

 - On FC9, I found the file 
	kvm03:~#  find /sys/block/nbd0/ | grep pid
	/sys/block/nbd0/pid

Did I missed something ? May udev changed ?

regards
Danny