NFSLOGD(1M)NFSLOGD(1M)NAMEnfslogd - nfs logging daemon
SYNOPSIS
/usr/lib/nfs/nfslogd
DESCRIPTION
The nfslogd daemon provides operational logging to the Solaris NFS
server. It is the nfslogd daemon's job to generate the activity log by
analyzing the RPC operations processed by the NFS server. The log will
only be generated for file systems exported with logging enabled. This
is specified at file system export time by means of the share_nfs(1M)
command.
NFS server logging is not supported on Solaris machines that are using
NFS Version 4.
Each record in the log file includes a time stamp, the IP address (or
hostname if it can be resolved) of the client system, the file or
directory name the operation was performed on, and the type of opera‐
tion. In the basic format, the operation can either be an input (i) or
output (o) operation. The basic format of the NFS server log is compat‐
ible with the log format generated by the Washington University FTPd
daemon. The log format can be extended to include directory modifica‐
tion operations, such as mkdir, rmdir, and remove. The extended format
is not compatible with the Washington University FTPd daemon format.
See nfslog.conf(4) for details.
The NFS server logging mechanism is divided in two phases. The first
phase is performed by the NFS kernel module, which records raw RPC
requests and their results in work buffers backed by permanent storage.
The location of the work buffers is specified in the /etc/nfs/nfs‐
log.conf file. Refer to nfslog.conf(4) for more information. The second
phase involves the nfslogd user-level daemon, which periodically reads
the work buffers, interprets the raw RPC information, groups related
RPC operations into single transaction records, and generates the out‐
put log. The nfslogd daemon then sleeps waiting for more information to
be logged to the work buffers. The amount of time that the daemon
sleeps can be configured by modifying the IDLE_TIME parameter in
/etc/default/nfslogd. The work buffers are intended for internal con‐
sumption of the nfslogd daemon.
NFS operations use file handles as arguments instead of path names. For
this reason the nfslogd daemon needs to maintain a database of file
handle to path mappings in order to log the path name associated with
an operation instead of the corresponding file handle. A file handle
entry is added to the database when a client performs a lookup or other
NFS operation that returns a file handle to the client.
Once an NFS client obtains a file handle from a server, it can hold on
to it for an indefinite time, and later use it as an argument for an
NFS operation on the file or directory. The NFS client can use the file
handle even after the server reboots. Because the database needs to
survive server reboots, it is backed by permanent storage. The location
of the database is specified by the fhtable parameter in the
/etc/nfs/nfslog.conf file. This database is intended for the internal
use of the nfslogd daemon.
In order to keep the size of the file handle mapping database manage‐
able, nfslogd prunes the database periodically. It removes file handle
entries that have not been accessed in more than a specified amount of
time. The PRUNE_TIMEOUT configurable parameter in /etc/default/nfslogd
specifies the interval length between successive runs of the pruning
process. A file handle record will be removed if it has not been used
since the last time the pruning process was executed. Pruning of the
database can effectively be disabled by setting the PRUNE_TIMEOUT as
high as INT_MAX.
When pruning is enabled, there is always a risk that a client may have
held on to a file handle longer than the PRUNE_TIMEOUT and perform an
NFS operation on the file handle after the matching record in the map‐
ping database had been removed. In such case, the pathname for the file
handle will not be resolved, and the log will include the file handle
instead of the pathname.
There are various configurable parameters that affect the behavior of
the nfslogd daemon. These parameters are found in /etc/default/nfslogd
and are described below:
UMASK
Sets the file mode for the log files, work
buffer files and file handle mapping data‐
base.
MIN_PROCESSING_SIZE
Specifies the minimum size, in bytes, that
the buffer file must reach before process‐
ing the work information and writing to the
log file. The value of MIN_PROCESSING_SIZE
must be between 1 and ulimit.
IDLE_TIME
Specifies the amount of time, in seconds,
the daemon should sleep while waiting for
more information to be placed in the buffer
file. IDLE_TIME also determines how often
the configuration file will be reread. The
value of IDLE_TIME must be between 1 and
INT_MAX.
MAX_LOGS_PRESERVE
The nfslogd periodically cycles its logs.
MAX_LOGS_PRESERVE specifies the maximum num‐
ber of log files to save. When MAX_LOGS_PRE‐
SERVE is reached, the oldest files will be
overwritten as new log files are created.
These files will be saved with a numbered
extension, beginning with filename.0. The
oldest file will have the highest numbered
extension up to the value configured for
MAX_LOGS_PRESERVE. The value of
MAX_LOGS_PRESERVE must be between 1 and
INT_MAX.
CYCLE_FREQUENCY
Specifies how often, in hours, the log files
are cycled. CYCLE_FREQUENCY is used to
insure that the log files do not get too
large. The value of CYCLE_FREQUENCY must be
between 1 and INT_MAX.
MAPPING_UPDATE_INTERVAL
Specifies the time interval, in seconds,
between updates of the records in the file
handle to path mapping tables. Instead of
updating the atime of a record each time
that record is accessed, it is only updated
if it has aged based on this parameter. The
record access time is used by the pruning
routine to determine whether the record
should be removed from the database. The
value of this parameter must be between 1
and INT_MAX.
PRUNE_TIMEOUT
Specifies when a database record times out,
in hours. If the time that elapsed since the
record was last accessed is greater than
PRUNE_TIMEOUT then the record can be pruned
from the database. The default value for
PRUNE_TIMEOUT is 168 hours (7 days). The
value of PRUNE_TIMEOUT must be between 1
and INT_MAX.
EXIT STATUS
The following exit values are returned:
0
Daemon started successfully.
1
Daemon failed to start.
FILES
/etc/nfs/nfslogtab
/etc/nfs/nfslog.conf
/etc/default/nfslogd
SEE ALSOshare_nfs(1M), nfslog.conf(4), attributes(5)
Dec 2, 2004 NFSLOGD(1M)
