Hours of tiny transfers at the end of a ZFS resilver?

[Ravi Pokala]

>Date: Mon, 15 Feb 2016 21:08:43 +0000
>From: Steven Hartland <killing at multiplay.co.uk>
>To: freebsd-fs at freebsd.org
>Subject: Re: Hours of tiny transfers at the end of a ZFS resilver?
>Message-ID: <56C23E5B.7060207 at multiplay.co.uk>
>Content-Type: text/plain; charset=windows-1252; format=flowed

Hi Steve,

>>[*] This is probably a good segue into discussing why we even have the ADA_Q_4K quirk, and whether we should get rid of it...? --rp
>The 4k quirks exists because a large amount of devices don't report 4k correctly instead just reporting 512 for both logical and physical even when they are actually 4k or larger physical sector size.

If true, that's a gross violation of ATA, and I would consider that a disqualifying firmware bug. After over a decade at a storage vendor, I've seen some *really* stupid firmware issues, but lying about the sector size would be a new low. :-(

Are we sure that they are really, truly claiming to be 512n rather than AF-512e, rather than us mis-parsing the sector sizes due to the aforementioned kernel bugs? If someone running -CURRENT has a drive which has the ADA_Q_4K quirk, could you paste the output of `geom disk list $DRIVE'?


Thanks,

Ravi (rpokala@)