Netatalk 4.5.0
Name
afpd — Apple Filing Protocol daemon
Synopsis
afpd [-d] [-F configfile]
afpd [-v | -V | -h]
Description
afpd provides an Apple Filing Protocol (AFP) interface to the Unix file system. It is normally started at boot time by netatalk(8).
afp.conf is the configuration file used by afpd to determine the behavior and configuration of a file server.
Options
-d
Do not disassociate daemon from terminal.
-v
Print version information and exit.
-V
Print verbose information and exit.
-h
Print help and exit.
-F configfile
Specifies the configuration file to use.
Signals
To shut down a user’s afpd process it is recommended that SIGKILL (-9) NOT be used, except as a last resort, as this may leave the CNID database in an inconsistent state. The safe way to terminate an afpd is to send it a SIGTERM (-15) signal and wait for it to die on its own.
SIGTERM and SIGUSR1 signals that are sent to the parent afpd process are propagated to the children, so all processes will be affected.
SIGTERM
Clean exit. Propagates from parent to children.
SIGQUIT
Sending this to the parent afpd will cause it to exit, but leaving all children running! This can be used to implement an AFP service without downtime.
SIGHUP
Sending a SIGHUP to afpd will cause it to reload its configuration files.
SIGINT
Sending a SIGINT to a child afpd enables max_debug logging and dumps caches to the system tmp directory:
- Debug log: afpd.PID.XXXXXX
- Directory cache: dircache.PID
Directory cache dump (see dircache mode in afp.conf(5)):
- LRU mode: Single queue of cached entries
- ARC mode: T1/T2 (cached), B1/B2 (ghost) lists, parameter p, statistics
Sending another SIGINT reverts to original log settings.
SIGUSR1
The afpd process will send the message “The server is going down for maintenance.” to the client and shut itself down in 5 minutes. New connections are not allowed. If this is sent to a child afpd, the other children are not affected. However, the main process will still exit, disabling all new connections.
SIGUSR2
Send a server message to the AFP client of a child afpd process. When the signal is received, afpd looks in the message directory (default: LOCALSTATEDIR/netatalk/msg/; the compiled-in path is printed by afpd -V) for a message file in the following order:
- message.PID — a file whose name ends with the child process ID
- message — a fallback used when no PID-specific file is found
The contents of the file are read and forwarded to the connected AFP client as a server message. The file is deleted after it is read. This signal must only be sent to a child afpd process. The parent afpd does not install a SIGUSR2 handler, so sending it there will terminate the parent process and prevent new connections.
Example usage:
# Find the child afpd PID for the connected user, then: echo "Scheduled maintenance tonight at 22:00" \ > LOCALSTATEDIR/netatalk/msg/message.PID kill -USR2 PID
Files
afp.conf
configuration file used by afpd
extmap.conf
file name extension mapping
afp_signature.conf
list of server signatures
afp_voluuid.conf
list of UUIDs for Time Machine volumes
LOCALSTATEDIR/netatalk/msg/message.PID, LOCALSTATEDIR/netatalk/msg/message
Server message files read on SIGUSR2. The PID-specific form (message.PID) targets a single connected client; the plain message form is a fallback when no PID-specific file exists. Both are deleted after being read. The compiled-in directory path is printed by afpd -V.
See Also
netatalk(8), hosts_access(5), afp.conf(5), afp_signature.conf(5), afp_voluuid.conf(5), extmap.conf(5), dbd(1)
