kern.cam…delay, suspend and ZFS pools on USB (was: rc.d/zpool runs before ada(4) attaches)

[Graham Perrin]

On 01/12/2020 20:23, tech-lists wrote:
> On Tue, Dec 01, 2020 at 08:34:33AM -0700, Ian Lepore wrote:
>> On Tue, 2020-12-01 at 16:22 +0100, Ronald Klop wrote:
>>>
>>> You can define these in /boot/loader.conf:
>>> #kern.cam.boot_delay="10000" # Delay (in ms) of root mount for CAM
>>> bus
>>> #kern.cam.scsi_delay="2000" # Delay (in ms) before probing SCSI
>>>
>>> Maybe that helps.
>>>
>>> Ronald.
>>>
>>
>> Those settings control waiting before mounting root.  Harry's problem
>> is that root is mounted quickly, before other drives are ready for zfs.
>>
>> The zpool script waits for 'disks'.  It would be nice if the cam
>> subsystem had something like a sysctl it set to indicate when initial
>> probing for disks was done, then there could be an rc.d/camprobe script
>> with 'PROVIDE: disks' which waits for the probing to complete.
>>
>> -- Ian
>
> kern.cam.boot_delay should still fix it because what is required is a 
> delay
> while the devices (all of the disks, zfs or not) get ready. Because 
> root has to happen before disks/zfs. 


Where a pool is on a USB 2.0 device: might kern.cam.boot_delay, or some 
other delay, negate the need to export the pool before suspending the 
computer?

Related: 
<https://lists.freebsd.org/pipermail/freebsd-current/2020-November/077681.html>