[asterisk-dev] dahdi and dracut initramfs

[Tzafrir Cohen]

Hi,

See https://issues.asterisk.org/jira/browse/DAHLIN-352
I'd like to know what effect it has on other DAHDI devices.
I believe it only has effect on Xorcom devices due to the odd
initialization (module initialization partially in userspace). But I 
may have missed something. So:

If the DAHDI modules load early in the initrd, will this cause any
problems?


Basically the issue is, as I understand it:

Dracut is a software to create an initramfs. That is, an initial minimal
system, that is intended to load the real root filesystem. This task is
fairly simple if the root filesystem resides on a partition on a disk.
But becomes more chalanging if it is on an LVM partition on a RAID
device connected through iSCSI[1].

Thus one of the thing dracut does is to copy all the kernel modules that
are currently loaded into the root filesystem. This allows loading them
when needed. For instance, whenever a device that supports one of them
pops out in one of the system's busses (PCI, USB, platform, whatever).

So a new kernel is installed after an Astribank was configured. Dracut
will see all the modules loaded and attempt to copy all of them (the
ones relevant for that version). When the dracut-generated initramfs
boots, it sees an Astribank and attempts to load the driver for it. This
sort-of works. However the Astribank's drivers include an odd
initialization sequence that requires running a script from userspace.
THat script is not found, and the initialization fails.

[1] A made up example that may or may not make sense and be supported in
dracut.

-- 
               Tzafrir Cohen
icq#16849755              jabber:tzafrir.cohen at xorcom.com
+972-50-7952406           mailto:tzafrir.cohen at xorcom.com
http://www.xorcom.com