I was debugging my why backup failed to run, and eventually found it was
stuck on sync:
14080 18:18 btrfs_tree_read_lock sync
This was hung for hours on this lock.
Strangely, it looks like taking my sysrq-w hung the machine pretty hard for
close to 30sec, but this seems to have unhung sync and in the end btrfs send
completed after that.
Sysqrq-w is here:
http://marc.merlins.org/tmp/sysrq-btrfs-sync-hang.txt
Marc
--
"A mouse is a device used to point at the xterm you want to type in" -
A.S.R.
Microsoft is to operating systems ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/
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