Hi Duncan,

On Fri, Jan 1, 2016 at 12:05 PM, Duncan [off-list ref] wrote:

John Center posted on Fri, 01 Jan 2016 11:41:20 -0500 as excerpted:

quoted

If this doesn't resolve the problem, what would you recommend my next
steps should be?  I've been hesitant to run too many of the btrfs-tools,
mainly because I don't want to accidentally screw things up & I don't
always know how to interpret the results. (I ran btrfs-debug-tree,
hoping something obvious would show up.  Big mistake. 😋)

LOLed at that debug-tree remark.  Been there (with other tools) myself.

Well, I'm hoping someone who had the problem can confirm whether it's
fixed in current kernels (scrub is one of those userspace commands that's
mostly just a front-end to the kernel code which does the real work, so
kernel version is the important thing for scrub).  I'm guessing so, and
that you'll find the problem gone in 4.3.

We'll cross the not-gone bridge if we get to it, but again, if the other
people who had the similar problem can confirm whether it disappeared for
them with the new kernel, it would help a lot, as there were enough such
reports that if it's the same problem and still there for everyone (which
I doubt as I expect there'd still be way more posts about it if so, but
confirmation's always good), nothing to do but wait for a fix, while if
not, and you still have your problem, then it's a different issue and the
devs will need to work with you on a fix specific to your problem.

Ok, I'm at the next bridge. :-(  I upgraded the kernel to 4.4rc7 from
the Ubuntu Mainline archive & I just ran the scrub:

john@mariposa:~$ sudo /sbin/btrfs scrub start -BdR /dev/md125p2
ERROR: scrubbing /dev/md125p2 failed for device id 1: ret=-1, errno=5
(Input/output error)
scrub device /dev/md125p2 (id 1) canceled
scrub started at Fri Jan  1 19:38:21 2016 and was aborted after 00:02:34
data_extents_scrubbed: 111031
tree_extents_scrubbed: 104061
data_bytes_scrubbed: 2549907456
tree_bytes_scrubbed: 1704935424
read_errors: 0
csum_errors: 0
verify_errors: 0
no_csum: 1573
csum_discards: 0
super_errors: 0
malloc_errors: 0
uncorrectable_errors: 0
unverified_errors: 0
corrected_errors: 0
last_physical: 4729667584

I checked dmesg & this appeared:

[11428.983355] BTRFS error (device md125p2): parent transid verify
failed on 241287168 wanted 33554449 found 17
[11431.028399] BTRFS error (device md125p2): parent transid verify
failed on 241287168 wanted 33554449 found 17

Where do I go from here?

Thanks for your help.

    -John