Bug#781886: qcontrol failure to start on boot sometimes (jessie, systemd?)

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On Thu, Apr 16, 2015 at 10:21:06 +0100, Ian Campbell wrote:
> BTW, when this fails the system still booted and you could login and fix
> it, i.e. it didn't stall the boot or anything, is that right? If that is
> the case a release note might be the most plausible action at this
> point.

When I saw the error message about the missing device file, everything else
seemed to work; I just ssh'ed in and restarted the qcontrol + qcontrold
services. Before that manual action, it did leave the front LED blinking 
red (I guess that's supposed to be cleared when boot completes) and I am 
assuming that the fans weren't controlled?

But I did have one occasion where one out of my 3 qnaps repeatedly failed to 
boot after the latest kernel update (or at least the latest flash-kernel
trigger, maybe it was caused by a systemd upgrade) in jessie. 
(The other 2 qnaps were also updated at the same time but survived.) 
I had to perform the TFTP recovery routine by building a TFTP version of the 
wheezy installer, so I could mount up and chroot into the target file system 
and re-run flash-kernel, which fixed it.  I've never had that issue before, 
ever. Perhaps this is completely unrelated and just a glitch in the flash?