Messages in this thread | | | Date | Thu, 29 Sep 2005 09:41:40 +0200 | From | Nico Schottelius <> | Subject | udev/modprobe issue |
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Good morning everybody!
I've a small problem with loading the sata_sil module, but it could be a general issue: We use this sata-kontroller with sata-harddisks to backup our systems. The harddisk is exchanged (while the system is running) every day. So we load/unload sata_sil in our backup scripts, so 'hotplugging' is possible.
My problem is, that modprobe returns earlier than the attached device is usable:
---------------------------------------------------------------------- srwali01:/# modprobe sata_sil; mount /dev/sda1 /mnt/hdbackup/ mount: you must specify the filesystem type srwali01:/# rmmod sata_sil srwali01:/# modprobe sata_sil; ls -l /dev/sda1 ls: /dev/sda1: No such file or directory ----------------------------------------------------------------------
So I have to do
---------------------------------------------------------------------- srwali01:/# modprobe sata_sil srwali01:/# sleep 2 srwali01:/# mount /dev/sda1 /mnt/hdbackup ----------------------------------------------------------------------
The problem is most likely that udev is too slow or that modprobe does not know/wait for udev:
---------------------------------------------------------------------- srwali01:/# mount | grep tmpfs | grep -v /dev/shm tmpfs on /dev type tmpfs (rw,size=10M,mode=0755) srwali01:/# cat /proc/sys/kernel/hotplug /sbin/udevsend ----------------------------------------------------------------------
My questions:
- Should modprobe wait for whatever current hotplug is so that the system can definitly use the device after modprobe? - Or should there be a command-line switch to modprobe to tell it to wait for hotplug? - Is the 'wait for hotplug'-idea possible to do or would it have to be a dirty hack in the kernel? - Is there clean solution to wait exactly as long as it needs to load sata_sil and create /dev/sda*? Using while+ls monitoring /dev/sda* is not a solution imho.
Greetings,
Nico
P.S.: Sorry for crossposting, I am not really sure which list would have been the correct one to ask.
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