bin/144214: zfsboot fails on gang block after upgrade to zfs v14

[Volodymyr Kostyrko]

The following reply was made to PR bin/144214; it has been noted by GNATS.

From: Volodymyr Kostyrko <c.kworr at gmail.com>
To: Andriy Gapon <avg at icyb.net.ua>
Cc: bug-followup <bug-followup at freebsd.org>, Robert Noland <rnoland at freebsd.org>
Subject: Re: bin/144214: zfsboot fails on gang block after upgrade to zfs v14
Date: Fri, 14 May 2010 17:12:23 +0300

 2010/5/13 Andriy Gapon <avg at icyb.net.ua>:
 >
 > It seems that I have been misunderstanding the problem.
 > "ZFS: gang block detected" won't even appear if boot code is too old.
 >
 > Having briefly glanced over the code and comparing it to the code in osol and in
 > zio_gang_tree_issue(), I think the following change is needed.
 > But I am not sure if it is a real fix for the issue at hand.
 >
 > If anyone can reproduce the problem, could you please test this change?
 > Thanks!
 
 Tested it. Same problem.
 
 1. Rebuild and reinstall on i386. Filling disk up (600M free of 120G, 0.5%).
 2. Immediately after starting boot screen bursts into psychic colors.
 Computer reboots.
 3. Booted from ftp://ftp.freebsd.org/pub/FreeBSD/snapshots/201004/FreeBSD-8.0-STABLE-201004-i386-livefs.iso
 in VirtualBox i386. Boot code updated with dd.
 4. Same as p2. in vBox i386 takes looong time to rotate dash then
 spits "ZFS: gang block detected" and hangs.
 5. Booted from amd64 install, updated boot code with dd.
 6. Booted on amd64. Immediately after starting boot spits out "ZFS:
 gang block detected" and hangs.
 7. Booted from amd64 install. /boot transferred transferred to/from other disk.
 8. Booted on amd64. Immediately after starting boot spits out "ZFS:
 gang block detected" and hangs.
 9. Booted from amd64 install. Some files deleted (800M free, files
 were written contiguously). /boot transferred transferred to/from
 other disk.
 10. Booted on amd64.
 
 Results:
 1. Patch changes something. However zfsloader(?) still can't be read completely.
 2. Bug can happen on amd64. More extreme conditions needed(?).
 3. I'll post a follow-up on successfully booting on original i386 hardware.
 
 -- 
 Sphinx of black quartz judge my vow.