Re: Advanced Startup/Shutdown with Multilayered Block Devices and Related Issues
Am Thu, 01 Jul 2010 09:31:47 +0200
schrieb Goswin von Brederlow <email@example.com>:
> The bigger problem is later during boot when you need to wait for all
> devices to appear so /usr, /home, ... can be mounted. One way to solve
> this would be to have the fsck and mounting of filesystems wait for
> the specified timeout for the device to appear as well. So even more
> event based stuff.
Event based init systems need some watchdog type behaviour in any case,
like "mountall" with upstart/ubuntu.
> Another issue is that in the case some device is missing and you do
> run into a timeout things have to timeout in the right order.
> E.g. /dev/md1 waits for /dev/sdc1 and lvm waits for /dev/md1.
> Then /dev/md1 has to timeout first and come up degraded so the lvm
> starts successfully. And I think at that point the only solution is
> to know the layering of devices so the layers can timeout lowest to
There are some notes at:
The init watchdog needs a list (or tree of dependencies) of
devices/events to wait for, degrade or fail.