Am Montag, 2. Juli 2007 schrieb Susan Zimmerman: > Hi Mark. > > I noticed /sys/class/misc/vmcp was 10 63 > > OSA-LNX1:~ # cat /sys/class/misc/vmcp/dev > 10:63 > > So I deleted /dev/vmcp and manually created the node > > as 10 63 > > and now it works just fine. > > Thanks for your help.
Yes, vmcp registers a misc device with dynamic minor number. Therefore it is normally not a good idea to have a permanent device node for vmcp, unless you know the load sequence of all your misc devices. Instead udev should be used. I know that this is getting trickier on an initrd. There is a problem assigned with udev: device node creation takes time. So after modprobe <module>, it can take some time to create a device node. (usually milliseconds, but it can take longer) Udev has improved a lot on SLES10 and RHEL5. On these systems you can use "udevsettle" to be sure that udev has finished all its work that was scheduled until now: # modprobe vmcp # udevsettle # vmcp my fancy command will always work as long as the kernel module was able to load. Furthermore, both systems use a tmpfs filesystem as /dev so your device folder is re-initialized during boot without stale device nodes. Things are much trickier on SLES9 and RHEL4. Both use an older udev version without udevsettle. SLES9 does not use tmpfs. SLES9 also does not use udev for devices, which exist during boot, unless you enable the boot.udev init script. RHEL4 uses udev for all devices, but has another issue. There is a race in the network hotplug scripts (I forgot the bugzilla number). In these script, hotplug is temporarily disabled and udev can loose events. If udev misses an event it will wait up to 10 seconds until it continues. Thats why on RHEL4 "modprobe vmcp -> /dev/vmcp appears" will often take 10 seconds. -- IBM Deutschland Entwicklung GmbH Vorsitzender des Aufsichtsrats: Martin Jetter Geschäftsführung: Herbert Kircher Sitz der Gesellschaft: Böblingen Registergericht: Amtsgericht Stuttgart, HRB 243294 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
