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This page has news, information, documentation and links software for the sysstat utilities that I created for Linux. The sysstat utilities are a collection of performance monitoring tools for Linux. These include sar, sadf, mpstat, iostat, pidstat and sa tools. Go to the Features page to display a list of sysstat's features, or see the Documentation page to learn some more about them.
Sysstat is Open Source / Free Software, and is freely available under the GNU General Public License, version 2.

Old news

Thursday May 24th, 2006

Sysstat 6.1.3 released (development version).
Several minor features and bug fixes were added in this version. Please read the changelog available from the download page for more details.

Sunday April 23rd, 2006

Sysstat 6.1.2 released (development version).
An important bug has been fixed in this version. Users wanting to get NFS statistics with sar are strongly encouraged to upgrade. Process statistics monitoring has also been improved with this version : sar is now able to display stats for processes that are launched during the execution of sar when option -x ALL or -X ALL is used.

Saturday April 8th, 2006

Sysstat web site has been completely redesigned! You can now find more documentation, sysstat Frequently Asked Questions (FAQ), and even a short online tutorial... Enjoy!

Wednesday February 22nd, 2006

Sysstat 6.1.1 released (development version).
Previous sysstat version appeared quite stable, so I decided to start a new development series. This version only adds CPU "steal" time to the stats displayed by sar -u, as I had promised to do.

Monday November 28th, 2005

Sysstat 6.0.2 released (stable version).
This version fixes a bug that was corrupting device names displayed by iostat on 64-bit architectures. It also adds a new field to mpstat and iostat to display CPU "steal" time (which is at the present time only used on s390 architectures!) Sar will also display this field when a new sysstat developmentr begins (6.1.x).

Saturday June 25th, 2005

Sysstat 6.0.1 released (stable version).
Several bugs have been fixed in this version, among them a memory leak and one that prevented sar -b from working. Also note that from now on, sar always displays the stats onto the screen even if a filename has been entered on the command line with option -o.

Saturday May 14th, 2005

Sysstat 6.0.0 released (stable version).
At last, a new sysstat stable release is available again. I have been really busy for the past few months, that's why sysstat development has slowed a bit. Anyway version 6.0.0 is here for you now, with new statistics gathered by sar and several bugs fixed. Oh, and I have named it 6.0.0 and not 5.2.0 for the format of sar logfiles is not compatible with that of sysstat 5.0.x...!

Friday February 25th, 2005

Sysstat 5.1.5 released (development version).
A new output format is now available to display sar data: using -x option with sadf enables you to create an XML document containing the statistics. The source package includes the corresponding DTD. This version also fixes a few bugs, one of them concerning some of the disks statistics as displayed by sar -d. Note that this version should be the last one of the development series (next release will be sysstat 5.2.0).

Sunday January 2nd, 2005

Sysstat 5.1.4 released (development version).
New stats have been added to sar : it can now collect and display NFS data of a client or server box. Also a few bugs have been fixed in this release: See changelog for details.

Monday November 22nd, 2004

Sysstat 5.1.3 released (development version).
Important things have been added here in this release: first, sar -d have been greatly improved with the addition of new fields displaying more disk activities. Moreover sar -d is now able to display device names as they appear in /dev thanks to a configuration file (sysstat.ioconf). Also sar -b is now working whatever the kernel version used, even with recent ones.

Friday November 5th , 2004

Sysstat 5.1.2 released (development version).
Numerous small changes in this version. More important is the /proc/partitions support which has been added to sar to get disk activity. Also note that beginning with sysstat 5.1.2 disk activity is no longer read by sadc by default: Option -d must be explictly set on the command line.

Saturday October 9th , 2004

Sysstat 5.1.1 released (development version).
That's it: A new development series starts with sysstat 5.1.1. Two important things here. First, sar reads several stat counters as 64-bit unsigned integers to follow 2.6 kernels changes. Also a new command named sadf has been added to sysstat. This command is aimed at displaying daily data files contents in various formats. At the present time, sadf only replaces sar -h and sar -H. Other possibilities will be added in future sysstat versions.

Monday August 9th , 2004

Sysstat 5.0.6 released (stable version).
OK. There is yet another stable version of sysstat, which fixes the value of a field displayed by sar -v that was wrongly calculated... See changelog for full details. Next version should (hopefully) be sysstat 5.1.1 which is planned for the end of october.

Tuesday June 8th , 2004

Sysstat 5.0.5 released (stable version).
Maybe the last stable version before the beginning of a new development series. This one fixes a bug in the binary RPM file, where symlinks to sysstat script were wrong in the /etc/rc.d directories. It also get rid of 'mojibakes' that sar and mpstat could have displayed with some locales (especially ja_JP).

Thursday May 20th , 2004

Sysstat 5.0.4 released (stable version).
Small but important fixes in this release : some of them concern the sysstat shell script called on system reboot. A bug introduced in version 5.0.1 prevented it from working properly (LINUX RESTART messages could no longer be added automatically to daily data files on system restart).

Wednesday April 7th , 2004

Sysstat 5.0.3 released (stable version).
Various fixes and improvements added in this version, among which the major one concerns the handling of 'unsigned long long' counters which are beginning to appear in the kernel (see kernel 2.6.5 for example). Also note that the isag tool has been upgraded and it should now really fix the small temporary file vulnerability. 

Wednesday March 10th , 2004

Sysstat 5.0.2 released (stable version).
OK, sysstat 5.0.2 is ready for download at last. A few bugs have been fixed in this version. But above all, iostat can look for its extended statistics in the /proc/partitions file again if available. /proc/partitions support had been removed in sysstat 4.1.3 in favor of sysfs included in 2.6 kernels. Its support has been added again here because many production servers are still using 2.2.x and 2.4.x kernels today.

Friday February 27th , 2004

Sysstat 5.0.2 will be released Wednesday, March 10th.
With this version, iostat will be able again to get its extended statistics from /proc/partitions on 2.2 and 2.4 kernels !

Monday February 2nd , 2004

Sysstat 5.0.1 released (stable version).
The main improvement in this version is the addition of option -L to sadc, enabling it to lock its output file to prevent multiple instances from writing to it at once. Beside this, do not hesitate to try this version with recent 2.6 kernels to make sure it is really stable.

Monday December 15th, 2003

Good news : From now on, you have access to the source packages of old sysstat versions. This may be useful for some people, for example those who are still running old kernels and want extended statistics information with iostat. See the download section.

Sunday November 9th, 2003

Sysstat 5.0.0 released (stable version).
Yes... You read it: the new sysstat version 5.0.0 is now available on your favorite web site ;-) It has new improvements again, and even the documentation has been enhanced. So, just try it and you will feel better! And if you find any bugs left, well, tell me...

Sunday September 28th, 2003

Sysstat 4.1.7 released (development version).
OK. Here is the first sysstat version which should be 100% compliant with 2.6 Linux kernels. This version uses /proc/diskstats in addition to sysfs to get statistics for devices. Also several new statistics were added to sar (page faults, swap cached, devices stats....) whereas other ones considered not really useful were removed.
I'm waiting now for your feedback so that sysstat 5.0.0 can be released soon. Enjoy...

Wednesday August 20th, 2003

Sysstat 4.1.6 released (development version).
This version contains another bunch of fixes and optimizations (iostat, sar, mpstat). See the changelog file for details. Oh, and option -F was added to sadc to force the creation of its daily data file. This is particularly useful to avoid the  Invalid system activity file  error messages you get when the format of those files changes.
PS: I hope that next sysstat release (4.1.7), planned for october, will be fully kernel 2.6 compliant. My goal is to start again with a stable series (5.0.x) before the end of the year.

Tuesday July 22nd, 2003

Sysstat 4.1.5 released (development version).
Several important fixes are included in this release : sar -x / -X now work again (a buglet in sysstat 4.1.4 made these options unavailable). Also a bug, introduced in the 4.1.x series, made some LINUX RESTART messages to not be displayed by sar ; this is fixed here. Last, sar -P now works properly on machines with more than 32 processors.

Monday June 30th, 2003

Sysstat 4.1.4 released (development version).
Various minor bugfixes are included in this version, like the way sar handles overflow with interfaces counters. Option  -x SUM  was removed from sar, since the calculation of the total number of faults made by the system was rather tricky. Also the code was greatly cleaned, and sysstat should now be really lighter than before as a consequence. 

Thursday May 8th, 2003

Sysstat 4.1.3 released (development version).
OK. This is the first version of sysstat to take advantage of the sysfs filesystem, included in recent, cutting-edge Linux kernels. Thus iostat should now be fully compliant with 2.5/2.6 kernels. But as a consequence, iostat will no longer look for statistics in the /proc/partitions file. Those who need to display extended statistics with iostat while still using an older 2.4 kernel must use sysstat 4.1.2 (or sysstat 4.0.7). With regard to sar, it has not been updated to use sysfs : I would rather wait for 2.6 kernels to be available...

Thursday January 23rd, 2003

Sysstat 4.1.2 released (development version).
Lots of small and not so small changes in this release. Among others, sar -q now also displays load average for the past 15 minutes, and option -P has been added to sar to display stats on a per processor basis. Because of this, sar syntax has changed a little : sar -U ALL is replaced by sar -u -P ALL (or simply sar -P ALL), and sar -I PROC is replaced by sar -I SUM -P ALL.

Thursday January 2nd, 2003

Sysstat 4.1.1 released (development version).
This new year starts with a new development series for sysstat. The result will be a set of commands that will work with cutting edge Linux kernels (2.5.x and above). Sysstat 4.1.1 is the first version in this series. It includes I/O wait support by all the commands of sysstat.

Wednesday November 13th, 2002

Sysstat 4.0.7 released (stable version).
Small changes in this version : 1) the data for midnight time (00:00:00) is now saved in the daily data file before sar/sadc rotates it ; 2) mpstat -P can now be used even on UP machines.
NB: A new development series (4.1.x) is to begin soon to take into account newer 2.5/2.6 kernels.