Connections fail due to dead NFS mount points
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Key: CORE-5458
URL: http://tracker.firebirdsql.org/browse/CORE-5458
Project: Firebird Core
Issue Type: Bug
Affects Versions: 2.5.2
Environment: Ubuntu 14.04.5 LTS, Firebird/linux AMD64 (access method),
version "LI-V2.5.2.26540 Firebird 2.5"
Reporter: Dirk Hagedorn
Short summary:
- Ubuntu Server runs Firebird 2.5.2 and has mounted two NAS via NFS
- both NAS have nothing to do with Firebird (no database related files on it)
- if a NAS doesn't respond anymore (shut down, cable unplugged) but NFS share
still mounted -> connection to Firebird possible anymore
- existing connections to Firebird keep working, new connections aren't
possible (no timeout, waits endlessly)
Some more words:
I have an Ubuntu server 14.04.5 LTS running Firebird 2.5.2 for some Windows
clients and local applications (running directly on the server) using isql-fb
or Perl::DBI. The attached NAS are mounted via NFS for backups. The NAS has
nothing to do with Firebird: No databases are stored on it, no configurations
files, no symbolic links are
I had to shut down one of the NAS and forgot to unmount its NFS share before. I
got some angry calls from the Windows users that "the tools don't work
anymore". "Hu? I shut down the NAS and the database applications won't work
anymore? WTF!?"
It turned out that no Firebird client was able to connect anymore, either the
local "isql-db" directly on the server or by ODBC-Client or by gds32.dll.
Nothing worked anymore, no warning, no timeout, the clients just waited
endlessly for a connection wich couldn't be established. Existing database
connections kept on working (sure, why shouldn't they, I just shut down a NAS?)
I can reproduce this phenomenon:
Scenario #1:
- keep NAS mounted via NFS, unplug its network cable = "dead" NFS mount -> no
Firebird connection possible / clients wait endlessly
- plug in network cable -> still waiting Firebird clients connect immediately
Scenario #2:
- unmount NAS before unplugging its network cable -> normal Firebird behaviour
= connections possible
Again: the database files are NOT stored on the NAS. Firebird does NOT have to
access the NAS for any purposes. But it hangs if the NFS mount is dead.
I haven't checked if it's NFS specific or if Firebird will even file with dead
(let's say) Samba mounts or anything else.
Connection method: The tools connect via "hostname:aliasname". I tried to
connect via isql-fb directly on the server with "isql-fb
/absolut/path/database.fdb -user bar -password bar", it didn't work either.
ISQL Version: LI-V2.5.2.26540 Firebird 2.5
Server version:
Firebird/linux AMD64 (access method), version "LI-V2.5.2.26540 Firebird 2.5"
Firebird/linux AMD64 (remote server), version "LI-V2.5.2.26540 Firebird 2.5/tcp
(neo)/P12"
Firebird/linux AMD64 (remote interface), version "LI-V2.5.2.26540 Firebird
2.5/tcp (neo)/P12"
on disk structure version 11.2
Sorry if this bug report doesn't fit your usual requirements. It's my first one
and I even registered here to report this weird issue.
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