Recent Posts by Tim Cook

One of the perennial performance or sizing questions for a workload is how much I/O it generates. This can be broken down several ways: Network versus disk Read versus write Random versus sequential (for the disk component) Many of the metrics have always been easy to quantify. There are standard operating system tools to measure disk I/O, network packets and bytes, etc. The question of how much random versus sequential I/O is much harder to answer, but it can be an important one...

Another minor nicstat release is now available. Changes for Version 1.95, January 2014 Common Added "-U" option, to display separate read and write utilization. Simplified display code regarding "-M" option. Solaris Fixed fetch64() to check type of kstats Fixed memory leak in update_nicdata_list() Availability nicstat source and binaries are available from sourceforge. History For more history on nicstat and examples of use, see my earlier entry

From the Obscure Unix Admin Tip of the Day section... If you occasionally edit files as root (I never do, I always use pfexec, wink wink), then you may have noticed that the vim (Vi Improved) editor that normally does filename completion via the <Tab> key now gives you something like: :e /etc/mo^I when you try to open up /etc/motd with a little less typing So, there are at least five solutions to this: Use <Ctrl>-E instead of <Tab> Use the "-N" flag when you start Vim :set...

Another minor nicstat release is now available. Changes for Version 1.92, October 2012 Common Added "-M" option to change throughput statistics to Mbps (Megabits per second). Suggestion from Darren Todd. Fixed bugs with printing extended parseable format (-xp) Fixed man page's description of extended parseable output. Solaris Fixed memory leak associated with g_getif_list Add 2nd argument to dladm_open() for Solaris 11.1 Modify nicstat.sh to handle Solaris 11.1 Linux Modify nicstat.sh...

It seems I have found a "bug" in Mercurial. It takes a shortcut when checking for differences in tracked files. If the file's size and modification time are unchanged, it assumes its contents are unchanged: $ hg init .$ cp -p .sccs2hg/2005-06-05_00\:00\:00\,nicstat.c nicstat.c$ ls -ogE nicstat.c-rw-r--r-- 1 14722 2012-08-24 11:22:48.819451726 -0700 nicstat.c$ hg add nicstat.c$ hg commit -m "added nicstat.c"$ cp -p .sccs2hg/2005-07-02_00\:00\:00\,nicstat.c nicstat.c$ ls...

This article is about interrupt analysis using DTrace. It is also available on the Solaris Internals and Performance FAQ Wiki, as part of the DTrace Topics collection. Interrupt Analysis Interrupts are events delivered to CPUs, usually by external devices (e.g. FC, SCSI, Ethernet and Infiniband adapters). Interrupts can cause performance and observability problems for applications. Performance problems are caused when an interrupt "steals" a CPU froman application thread,...

Yes! A new version is now available with some long-awaited features. Many thanks to those who suggested improvements and helped with testing. Changes for Version 1.90, April 2011 Common nicstat.sh script, to provide for automated multi-platform deployment. See the Makefile's for details. Added "-x" flag, to display extended statistics for each interface. Added "-t" and "-u" flags, to include TCP and UDP (respectively) statistics. These come from tcp:0:tcpstat and udp:0:udpstat on...

Back in the day (ahem, Solaris 10 and earlier...) you could use a command like the following to figure out which package was responsible for; e.g.; "/usr/include/math.h", or any other "include/math.h", just in case it is somewhere less obvious: mashie$ fgrep include/math.h /var/sadm/install/contents/usr/include/math.h f none 0644 root bin 10514 7356 1249334889 SUNWlibm In other words, /var/sadm/install/contents was a flat-file index of every file, directory, link, etc....

Table of Contents RAC Cache Fusion on SPARC Enterprise T5440 1 Summary of Findings Configuration Under Test 10 Gigabit versus 1 Gigabit Interconnect Scaling up Number of LMS Processes Theoretical Peak of 10 Gigabit Interconnect CPU Tuning – Processor Sets and Interrupt Fencing Network Tuning Choice of Block Size Impact of Additional 10 Gigabit Interface How About if We Use Remote SQL\*Plus Clients? Bi-Directional Cache Fusion test CPU Impact of Select Tunings Appendix A – Notes on the...