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2.16. Are the measurements gathered by sadc cumulative or instantaneous?
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2.17. Some fields are always displayed as 0.00 when I use the sar -d
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2.18. The sar command complains with the following message:
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"Requested activities not available".
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2.19. How can I keep sar data for more than one month?
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3. QUESTIONS RELATING TO IOSTAT
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options -s and -e. Unfortunately, I have nothing displayed at all.
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This is because no data belong to the specified time interval!
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In fact, -p option makes sadf display its timestamp as a UTC value
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(Coordinated Universal Time), as indicated in the manual page. The UTC value
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may be different from the value that sar (or sadf without option -p) displays.
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The same remark applies to the use of -d option.
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With versions older than 7.0.1, the time specified by options -s or -e
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may be considered as given in UTC (Coordinated Universal Time) or local
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time depending on whether sadf displays its output in UTC or local time.
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Option -p makes sadf display its timestamp in UTC, as indicated in the
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manual page. The UTC value may be different from the value that sar
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(or sadf without option -p) displays. The same remark applies to the
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Several such tools are lying around on the internet. I haven't tested all of
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them and there must still be some way for improvement...
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You can find among others: isag (a Perl script included in the sysstat
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package), sarvant, sar2gp, loadgraph, SysStat Charts...
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package), sarvant, sar2gp, loadgraph, SysStat Charts, sarplot...
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I've also heard of commercial tools which use sysstat: PerfMan comes to mind,
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If you find others which you think are of real interest, please let me know
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2.14. The sar command complains with the following message:
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Requested activities not available in file.
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Requested activities not available in file
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This error message means that you are trying to extract non-existent activities
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from the data file. Usually sadc reads all the available activities from the
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from a data file.
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NB: If the sar command complains with the error message:
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"Requested activities not available" (without mentioning "in file"),
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it means that you are trying to display activities that the kernel itself is
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please see question 2.18 below.
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See question 3.2 below.
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2.18. The sar command complains with the following message:
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Requested activities not available
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This error message means that you are trying to display activities that the
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kernel itself is unable to provide.
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When this error message is displayed while trying to save the data into an
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existing file ("sar -o datafile ..."), this may also be because the target
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file cannot accept the requested activities. In this case, just try to use
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another file or create a new one.
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2.19. How can I keep sar data for more than one month?
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By default sar saves its data in the standard system activity data file,
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the /var/log/sa/sa<DD> file, where <DD> is the current day in the month.
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To prevent sar from overwriting any existing files, just set the variable
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HISTORY in /etc/sysconfig/sysstat to the number of days during which data
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must be kept. When this variable has a value greater than 28, sa1 script
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uses a month-by-month directory structure; datafiles are named YYYYMM/saDD
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and the script maintains links to these datafiles to mimic the standard
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sar datafile structure.
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However please note that pre-existing datafiles will be deleted as links
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will be created and replace them.
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3. QUESTIONS RELATING TO IOSTAT
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