HP Tru64 UNIX and TruCluster Server Version 5.1B-6 Patch Summary and Release Notes

New Sysconfig Tunable to Reduce Contention on AdvFS Frag Files
A new sysconfig tunable AdvfsFragGroupDealloc has been introduced to set the frag group
deallocation policy for the AdvFS filesystem. Using this tunable, you can enable or disable the
frag group deallocation policy. The default is enabled .
File operations such as rm and close, which release a single frag, can trigger the frag group
deallocation process when a list of free frags is encountered. This process holds a lock while
processing the frag group. Any other process or thread that tries to manipulate the same frag
group experiences a hang due to lock contention. The hang lasts for the duration of the frag
group processing. This situation arises when the frag file of a fileset is large and too many files
are present with frag. The AdvfsFragGroupDealloc tunable helps in disabling the frag group
deallocation, which reduces the lock contention on the frag file.
The AdvfsFragGroupDealloc tunable can be added to the /etc/sysconfigtab file, and a
value can be assigned as per the desired frag group deallocation policy. Placing the tunable in
the /etc/sysconfigtab file will make the value persist across system reboots. Alternatively,
/sbin/sysconfig –r can be used to assign the value for the tunable. However, this does not
persist across system reboots.
On a cluster this tunable must be set on all the cluster members.
New rc.config Variables to Hide User Process Arguments and Environmental
Variables for ps and w Commands
By default, the ps command displays a process's arguments and the ps e command displays a
process's environmental variables. You can prevent users from viewing the arguments and
environmental variables of other users' processes. To hide user process arguments and variables,
enable the variables in the /etc/rc.config.common file:
# rcmgr -c set TBL_ARGUMENTS_DISABLE 1
# rcmgr -c set TBL_ENVIRONMENT_DISABLE 1
However, the root can always view the arguments and environmental variables of all users.
Similarly, the w command displays commands and their arguments. To prevent users from
viewing commands and the arguments of other users' processes, enable the variable in the /etc/
rc.config.common file:
# rcmgr -c set TBL_ARGUMENTS_DISABLE 1
However, the root can always view the arguments of all users.
Conformance to Open Group Standards
Set the STDS_FLAG environment variable to ALL so that pthread_mutexattr_getprotocol()
conforms to the Open Group standard.
UNIX 98 Compliance with libc
Some libc functions from the printf, scanf, and streams family have been made to comply
with UNIX 98 standards. These setting are enabled using the sys_attrs_generic variable,
std_unix98. This variable (std_unix98) should not be set to the value of STD_UNIX98_ALL
without consulting the Tru64 engineering team. For more information, see the
sys_attrs_generic manpage .
Netstat Read Error on Structures in a Live System
When trying to read a structure, the netstat() command displays the following message:
netstat: read from /dev/kmem: No such device or address
This can result from netstat reading structures that are dynamically undergoing change on a
live system. This is a transient problem that will be reported to the user.
Prior Release Notes 27