zfs problems after rebuilding system [SOLVED]

[Eugene Grosbein]

03.03.2018 19:56, Bruce Evans wrote:

> On Sat, 3 Mar 2018, tech-lists wrote:
> 
>> On 03/03/2018 00:23, Dimitry Andric wrote:
>>> Indeed.  I have had the following for a few years now, due to USB drives
>>> with ZFS pools:
>>>
>>> --- /usr/src/etc/rc.d/zfs    2016-11-08 10:21:29.820131000 +0100
>>> +++ /etc/rc.d/zfs    2016-11-08 12:49:52.971161000 +0100
>>> @@ -25,6 +25,8 @@
>>>
>>>  zfs_start_main()
>>>  {
>>> +    echo "Sleeping for 10 seconds to let USB devices settle..."
>>> +    sleep 10
>>>      zfs mount -va
>>>      zfs share -a
>>>      if [ ! -r /etc/zfs/exports ]; then
>>>
>>> For some reason, USB3 (xhci) controllers can take a very, very long time
>>> to correctly attach mass storage devices: I usually see many timeouts
>>> before they finally get detected.  After that, the devices always work
>>> just fine, though.
> 
> I have one that works for an old USB hard drive but never works for a not
> so old USB flash drive and a new SSD in a USB dock (just to check the SSD
> speed when handicapped by USB).  Win7 has no problems with the xhci and
> USB flash drive combination, and FreeBSD has no problems with the drive
> on other systems.
> 
>>> Whether this is due to some sort of BIOS handover trouble, or due to
>>> cheap and/or crappy USB-to-SATA bridges (even with brand WD and Seagate
>>> disks!), I have no idea.  I attempted to debug it at some point, but
>>> a well-placed "sleep 10" was an acceptable workaround... :)
>>
>> That fixed it, thank you again :D
> 
> That won't work for the boot drive.
> 
> When no boot drive is detected early enough, the kernel goes to the
> mountroot prompt.  That seems to hold a Giant lock which inhibits
> further progress being made.  Sometimes progress can be made by trying
> to mount unmountable partitions on other drives, but this usually goes
> too fast, especially if the USB drive often times out.

In fact, we have enough loader.conf quirks for that:
 
kern.cam.boot_delay	"Bus registration wait time" # miliseconds
vfs.mountroot.timeout	"Wait for root mount" # seconds
vfs.root_mount_always_wait "Wait for root mount holds even if the root device already exists" # boolean

No need in extra hacks to zfs rc.d script.