HP CIFS Server Administrator's Guide Version A.03.01.01 (5900-1282, May 2011)

What to Do if You Encounter Memory Map Error Messages
This section includes information about memory map error messages and actions you may take as
follows:
• The HP CIFS Server will terminate the connection and log the following error messages, in the
event that the value of fixed mmap size is not sufficient:
"tdb_expand: ERROR. Requested size (%d) > fixed mmap size (%d).
Please increase the value of "fixed mmap size" option then restart
CIFS Server"
"mmap_if_required: ERROR. "fixed mmap size" parameter must be at
least 8192 bytes.\n"
NOTE: The fixed mmap size parameter does not support A.03.01.01 on HP-UX 11i v2
IA/PA. Hence without the fixed mmap size parameter, the use mmap=yes is not
functional. Use the default value use mmap=no for HP-UX 11i v2 IA/PA.
To resolve the above errors, you must increase the value of fixed mmap size in smb.conf
accordingly and then restart the HP CIFS Server.
• Memory-mapped access fails when the system is low on memory resources. In this case, the
HP CIFS Server will terminate the connection and log the following error messages:
"ERROR. Abort due to munmap failure."
"ERROR. Abort due to tdb_mmap failure."
To resolve the above errors, you can turn off the memory map feature by setting the value of
use mmap to no and then restart the HP CIFS Server.
Constraints
The HP CIFS Server TDB memory map support has the following constraints:
• NOTE: Do not have binaries from mixed versions of mmap and non-mmap daemons/utilities
of CIFS Server in the /opt/samba/bin subdirectory.
• You must use the tdbbackup utility to backup TDB files, do not use the cp command to
backup TDB files.
Overview of Kernel Configuration Parameters
The kernel configuration parameters, maxuser, nproc, ninode, nflocks and nfile are described
below. These are the kernel parameters that you must adjust to support a large number of clients
on HP CIFS.
• maxusers: the name of this kernel parameter is a misnomer as it does not directly control the
number of UNIX users that can logon to HP-UX. However, this kernel parameter is used in
various formulae throughout the kernel. In fact, the default values for nproc, nfiles and ninodes
are expressed in terms of maxusers.
• nproc: this kernel parameter controls the size of the process table. Its default formula is
(20+8*maxusers). On most systems the default value for this parameter is 21, which yields
a default value of 20+8*32 or 276 maximum processes supported. When this table fills up
prior to launching a process, the error message "proc: table is full" will appear on the console.
It will be viewable via the dmesg command.
• nfiles: this kernel parameter controls the size of the system file table and limits the total number
of open files in the system. Note that this affects each instance of an open file since the same
file opened twice would take up 2 entries in the system file table. This default formula is
156 HP-UX Configuration for HP CIFS