Re: xfsdump completes very prematurely in low RAM, commit found

Dave Chinner
2014-08-20T23:47:39Z

On Mon, Aug 18, 2014 at 09:12:28AM -0400, Michael L. Semon wrote:
> On 08/17/14 22:41, Dave Chinner wrote:
> >On Sun, Aug 17, 2014 at 10:03:27PM -0400, Michael L. Semon wrote:
> >>Hi! I had some phantom issues that are chasing me through this 3.17
> >>merge window period. While chasing those issues, I decided to do an
> >>xfsdump of a v5/finobt XFS system rescued from PEBKAC issues. The
> >>xfsdump completed rather prematurely, ending like this test case
> >>output...
> >>
> >>xfsdump: dumping special file ino 4194523 mode 0x21b0
> >>xfsdump: dumping special file ino 4194524 mode 0x21b0
> >>xfsdump: dumping special file ino 4194525 mode 0x21b0
> >>xfsdump: dumping special file ino 4194526 mode 0x21b0
> >>xfsdump: dumping special file ino 4194527 mode 0x21b0
> >>xfsdump: ending media file
> >>xfsdump: media file size 4512992 bytes
> >>xfsdump: ending stream: 23 seconds elapsed
> >>xfsdump: dump size (non-dir files) : 4452088 bytes
> >>xfsdump: dump complete: 23 seconds elapsed
> >>xfsdump: Dump Summary:
> >>xfsdump: stream 0 /mnt/xfstests-scratch/blah.0.dump OK (success)
> >>xfsdump: Dump Status: SUCCESS
> >>
> >>That looks fine for a lack of obvious error messages. However, it
> >>should end like this:
> >>
> >>xfsdump: dumping regular file ino 13653551 offset 0 to offset 12154 (size 12154)
> >>xfsdump: dumping regular file ino 13653555 offset 0 to offset 16554 (size 16554)
> >>xfsdump: dumping regular file ino 13653556 offset 0 to offset 185 (size 185)
> >>xfsdump: dumping regular file ino 13653557 offset 0 to offset 471 (size 471)
> >>xfsdump: dumping special file ino 13653558 mode 0xa1ff
> >>xfsdump: ending media file
> >>xfsdump: media file size 1999127056 bytes
> >>xfsdump: ending stream: 465 seconds elapsed
> >>xfsdump: dump size (non-dir files) : 1963549104 bytes
> >>xfsdump: dump complete: 465 seconds elapsed
> >>xfsdump: Dump Summary:
> >>xfsdump: stream 0 /mnt/xfstests-scratch/blah.0.dump OK (success)
> >>xfsdump: Dump Status: SUCCESS
> >
> >What's the inode number progression of a successful dump at the
> >point at which the incomplete dump ends? i.e. around inode 4194527?
> >That number is one inode chunk short of 2^22, which implies that
> >there is a failure or some kind moving from one AG to the next.
> >The progrssion of inode numbers will tell me whether this is the
> >case or not...
>
> It is this, run a bit longer to show xfsdump start to dump regular
> files again:
>
> xfsdump: dumping special file ino 4194520 mode 0x21b0
> xfsdump: dumping special file ino 4194521 mode 0x21b0
> xfsdump: dumping special file ino 4194522 mode 0x21b0
> xfsdump: dumping special file ino 4194523 mode 0x21b0
> xfsdump: dumping special file ino 4194524 mode 0x21b0
> xfsdump: dumping special file ino 4194525 mode 0x21b0
> xfsdump: dumping special file ino 4194526 mode 0x21b0
> xfsdump: dumping special file ino 4194527 mode 0x21b0
> xfsdump: dumping special file ino 4194528 mode 0x21b0
> xfsdump: dumping special file ino 4194529 mode 0x21b0
> xfsdump: dumping special file ino 4194530 mode 0x21b0
> xfsdump: dumping special file ino 4194531 mode 0x21b0
> xfsdump: dumping special file ino 4194532 mode 0x21b0
> xfsdump: dumping special file ino 4194533 mode 0x21b0
> xfsdump: dumping special file ino 4194534 mode 0x21b0
> xfsdump: dumping special file ino 4194535 mode 0x21b0
> xfsdump: dumping special file ino 4194536 mode 0x21b0

So it's not the end of the AG that is causing problems. Can you get
a tracepoint dump of the failing xfsdump run? i.e.

$ trace-cmd record -e xfs\* <xfsdump command>
.....
$ trace-cmd report > traces.txt

and send me that traces.txt file (compress it first, please).

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com