Ceph

I've hit a few crashes on mira nodes, only to find that
kdb was not working. I thought it may have been due
to VPN issues or something, but just now I tried to
forcefully drop a mira machine into kdb, only to find
it was not responsive to keyboard input after that.

It appears as though kdb output works, but input seems
to never be seen. So for example when it shows a
"more" prompt, space or return (or any other key) has
no effect.

Here's what it looks like after I did this command
in a separate window, to force kdb:

In the other window:
root@mira096:~# echo g > /proc/sysrq-trigger

(This is normal--prompt doesn't return until/unless you tell
kdb to continue at the console.)

On the console:
[81625.533455] libceph: mon1 10.214.136.128:6789 session lost, hunting for new mon
[81625.550583] libceph: mon0 10.214.136.112:6789 session established
[100667.370916] libceph: mds0 10.214.136.128:6809 socket closed (con state OPEN)
[104400.158806] libceph: mds0 10.214.136.128:6809 socket closed (con state OPEN)
[105143.883674] SysRq : DEBUG

Entering kdb (current=0xffff88041478deb0, pid 30631) on processor 1 due to Keyboard Entry
[1]kdb>

Without this functionality my kernel debugging effectiveness
is limited a lot. (It's possible to set up gdb to target a
a virtual machine kernel, but I still want kdb to function.)

It may be a simple configuration option somewhere.