ZFS not mounted on reboot - Possibly udev

Question

Linux nicenas 3.18.4-1-ARCH #1 SMP PREEMPT Tue Jan 27 20:45:02 CET 2015 x86_64 GNU/Linux
zfs-git 0.6.3_r170_gd958324f_3.18.4_1-1
From Repo: demz-repo-core
My system recently crashed and I was forced to recreate my system drive.   Luckily I stored all of my data in a zfs pool.   I setup a new copy of Arch and installed the zfs kernel packages.
I executed:
zpool import media
zpool set cachefile=/etc/zfs/zpool.cache media
systemctl enable zfs.target
systemctl start zfs.target
Everything mounted just fine.
The problem is that now after every reboot it does not mount.  My first thought was that there was an issue with the hostid.   I verified that my hostid was the same in zdb as well as `hostid` and just for the sake of it I also added it as a kernel parameter.
After lots of ripping through logs and support posts I decided to add debug to the kernel command line.  Once debug was enabled it would mount on every boot.   This leads me to believe that there's a timing issue.   Maybe the drives take too long to be detected... Not sure.   But I don't know how to find out.
Can anyone offer advice on how to figure out which service to put the delay on and how?
Thanks
Last edited by msalerno (2015-01-30 14:06:38)

Answer 1

Update:
I disabled debug from kernel and rebooted a few times.  Each time the zfs pool was not mounted.   My next step was to add debug to UDEV.   The problem is that when I added debug to udev, the pool would mount.
How do I troubleshoot this?