Problem still exists on 4.4.0-97-generic. And in my attempt to reproduce
it on a VM, I got a corrupt kernel instead, which sounds worse (could
create some persistent damage, not just a hang).
Attached are the 3 scripts to reproduce the corrupt kernel, and an extra
one to attach if the first failed.
- Make a VM with at least 2GB RAM.
- Run crash-setup first (it uses a loop device backed by something in /dev/shm
so it doesn't have to wear out an SSD).
- Then verify the cache is attached, or attach it if not.
Output of these 2 should match:
bcache-super-show /dev/loop0 | awk '$1=="cset.uuid"{print $2}'
basename $(readlink /sys/block/bcache0/bcache/cache)
This should say [writeback]:
cat /sys/block/bcache0/bcache/cache_mode
eg. writethrough [writeback] writearound none
- Then run the setup-grep and the setup-fio at the same time, like in screen or
2 terminals. The grep is not intended to be only information output... I
strongly believe that reading the files in sysfs causes crashing, as I have
caused hangs and other problems many times this way in the
past.
- wait a while... could be as soon as 20 minutes, or some hours.
So far I made this VM die 3 times... it wasn't possible ot get the
console output or dmesg as I wanted and I didn't save a screenshot
either the first 2 times... and the 3rd time also failed, even with a
serial console set up, so attached is a screenshot.
** Attachment added: "bcachecrash.tgz"
https://bugs.launchpad.net/ubuntu/+source/linux-lts-xenial/+bug/1724173/+attachment/5008126/+files/bcachecrash.tgz
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1724173
Title:
bcache makes the whole io system hang after long run time
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux-lts-xenial/+bug/1724173/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
