gptzfsboot very slow

[David Wimsey]

On Oct 20, 2012, at 12:32 PM, "Andrey V. Elsukov" <ae at FreeBSD.org> wrote:

> On 20.10.2012 12:50, David Wimsey wrote:
>> My file server is configured with zfs root based on
>> http://wiki.freebsd.org/RootOnZFS/GPTZFSBoot/Mirror
>> 
>> When booting, after it gets past the BIOS drive C: is disk0 (one line
>> for each of the 6 drives as expected) part, drops to a new line and
>> the rotating twiddle starts its bit.  At first it moves a long at a
>> almost normal looking speed, then it starts only ticking away slowly,
>> maybe once or twice a minute.
>> 
>> It appears that its scanning the entire drive or something odd.  Its
>> hard to tell if its doing it on all the drives as half of them are on
>> a RocketRAID card (configured as JBOD) which doesn't have a LED
>> indicator attached to it for showing activity.
>> 
>> There are a total of  6 drives in the machine.
>> 
>> 2 drives are SSDs which are sliced up to provide the root mirror
>> vdev, a mirrored vdev for the zip if the main pool on the machine and
>> each provide a slice L2ARC.  Some of the remaining space is in a
>> small pool 3 of the HDDs are part of a raidz vdev for my main pool. 
>> The remaining HDD is a hot spare.
>> 
>> If I remove the HDDs from the system and just let the SSDs handle the
>> boot, its faster but still far longer than it should be, so when I'm
>> in a hurry I unplug the 4 HDDs, boot, wait for it to get to the
>> FreeBSD boot menu, plug the HDDs back in and send it on its marry
>> way.
>> 
>> This can not be expected behavior in my mind.  Why is it doing so
>> much disk thrashing when the pools are all perfectly clean.
> 
> Hi, David.
> 
> These lines are not from gptzfsboot, but from the loader. You can try
> the loader(8) from the FreeBSD 10-CURRENT, you may take it  from recent
> snapshot:
> https://pub.allbsd.org/FreeBSD-snapshots/amd64-amd64/10.0-HEAD-20121006-JPSNAP/stage/trees/boot/zfsloader
> 
> -- 
> WBR, Andrey V. Elsukov
> 
> -- 
> WBR, Andrey V. Elsukov
> 


Ding!  We have a winner!

The new  zfsloader fixed the problem, the twiddle keeps spinning fast and only takes a few seconds before jumping to the boot menu.

Thanks!

Just out of curiosity, do you know what change fixed it or what exactly the old loader was doing?