When I run out of diskspace I currently see this:

Sat May 9 13:12:52 allocating new datafile /ram/mongo_1/test.5, filling with zeroes...
Sat May 9 13:12:55 Assertion: write failed
Sat May 9 13:12:55 Got signal: 11 (Segmentation fault).
Sat May 9 13:12:55 Last op: { opid: 227, active: 0, op: "update", ns: "test.data", query: "

", inLock: 0 }
Sat May 9 13:12:55 Backtrace:
0x52545f 0x2b5d4f13294d 0x2b5d4f12ffab 0x2b5d4f1334e0 0x2b5d4f12febe 0x2b5d4e4b9d00 0x2b5d4fc8e400 0x2b5d4e65312a 0x4e6662 0x418c06 0x529f9c 0x2b5d4e7cdcac 0x2b5d4e4b30fa 0x2b5d4fcd966e
mongod(_ZN5mongo10abruptQuitEi+0x7af) [0x52545f]
/opt/m1/sys/jdk/jre/lib/amd64/server/libjvm.so [0x2b5d4f13294d]
/opt/m1/sys/jdk/jre/lib/amd64/server/libjvm.so [0x2b5d4f12ffab]
/opt/m1/sys/jdk/jre/lib/amd64/server/libjvm.so(JVM_handle_linux_signal+0x170) [0x2b5d4f1334e0]
/opt/m1/sys/jdk/jre/lib/amd64/server/libjvm.so [0x2b5d4f12febe]
/lib/libpthread.so.0 [0x2b5d4e4b9d00]
/lib/libc.so.6(strlen+0x10) [0x2b5d4fc8e400]
/usr/lib/gcc/x86_64-pc-linux-gnu/4.1.1/libstdc++.so.6(_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc+0x5a) [0x2b5d4e65312a]
mongod [0x4e6662]
mongod [0x418c06]
mongod [0x529f9c]
/usr/lib/libboost_thread-mt.so(thread_proxy+0x6c) [0x2b5d4e7cdcac]
/lib/libpthread.so.0 [0x2b5d4e4b30fa]
/lib/libc.so.6(__clone+0x6e) [0x2b5d4fcd966e]
Sat May 9 13:12:55 dbexit:
Sat May 9 13:12:55 MessagingPort recv() error 9 127.0.0.1:52142
Sat May 9 13:12:55 end connection 127.0.0.1:52142
Sat May 9 13:12:55 connection accepted from 127.0.0.1:53934
Sat May 9 13:12:55 Listener on port 5001 aborted

Further observations:

• The mongod process keeps running
• All active connections appear to be deadlocked (not timing out)
• SIGTERM triggers this msg: "got kill or ctrl c signal 2 (Interrupt), will terminate after current cmd ends"

This doesn't feel right.
"Disk full" is a corner case but a critical one. It can and does happen in production.

Questions:

• What happens to operations that were in flight when the "disk full" happened?
• What is our on-disk state, are we corrupted now?

Wishes:

• Disk-Full should be handled gracefully. Db corruption must be avoided. mongod should shutdown cleanly.