A file descriptor is a handle created by a process when a file is opened. A new descriptor is created each time the file is opened. It is associated with a file object which includes information such as the mode in which the file was opened and the offset pointerwhere the next operation will begin. This information is called the context of the file.
File descriptors are retired when the file is closed or the process terminates. Opens always choose the lowest-numbered file descriptor available.
The following steps are required to change a Sun system's hostname.
As a long time Sun employee, I've often heard the term "Slow-laris" applied to Oracle's premier Unix operating system. Most frequently this was in comparison to the Linux OS running on small two socket servers. I will admit that in the Solaris 8 and 9 timeframe engineering decisions were made to benefit scalability to 64 sockets that sometimes penalized smaller servers.
Performance results for the new SPARC T5 systems keep coming in...
Last week, SPEC published the most recent result for the SPECjbb013-MultiJVM benchmark.
This benchmark "is relevant to all audiences who are interested in Java server performance, including JVM vendors, hardware developers, Java application developers, researchers and members of the academic community" according to SPEC.
All of the published results are at: http://www.spec.org/jbb2013/results/jbb2013multijvm.html.
While woking with ZFS performance I created a dashboard to get a good overview with lots of different statistics. It's powered by Dtrace, python and graphite. There is a high level of detail but still easy to correlate different statistics.
It feels almost like fishworks analytics lite but without advanced features such as drill-down and heat maps. An example from a box running OpenIndiana:
For a system to produce a panic core dump, savecore must be enabled (by uncommenting and editing the savecore lines in
/etc/init.d/sysetup in Solaris 2.6 and earlier, or by
/etc/init.d/savecore in Solaris 7 and later). If the system is hung, it may be necessary to force a panic by using Stop-a and typing
sync at the
ok> prompt. (
sync forces a write from memory to swap.)
There are several reasons why savecore may be unable to save a core following a panic. These include: