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sysstat not recording historical disk stats

Hi All,

Anyone come across the following;

I'm looking at disk stats using sar, if I run `sar -d 5 1` I get the following (trimmed) output.

   Linux 2.6.18-92.1.22.el5         03/29/2009

   05:38:59 PM       DEV       tps  rd_sec/s  wr_sec/s  avgrq-sz  avgqu-sz     await     svctm     %util
   05:39:04 PM    dev8-0      1.20      0.00     28.80     24.00      0.01      5.17      5.17      0.62
   05:39:04 PM   dev8-16      1.20      0.00     28.80     24.00      0.01      8.50      8.50      1.02
   05:39:04 PM    dev9-1      2.80      0.00     22.40      8.00      0.00      0.00      0.00      0.00
   05:39:04 PM    dev9-0      0.00      0.00      0.00      0.00      0.00      0.00      0.00      0.00

   Average:          DEV       tps  rd_sec/s  wr_sec/s  avgrq-sz  avgqu-sz     await     svctm     %util
   Average:       dev8-0      1.20      0.00     28.80     24.00      0.01      5.17      5.17      0.62
   Average:      dev8-16      1.20      0.00     28.80     24.00      0.01      8.50      8.50      1.02

All seems well so far, however, if I want to look at historical disk stats I type `sar -d -f /var/log/sa/sa28` for example but I get:-
   # sar -d -f /var/log/sa/sa28
   Requested activities not available in file

The cron job runs `sa2 -A` which should record the disk information.

Is there a bug in sysstat? I can't seem to find anything on the net about it...


O/S Centos 5.2 (updated)
sysstat = sysstat-7.0.2-1.el5



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jools
Asked:
jools
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1 Solution
 
martin_2110Commented:
There is no bug it is turned off by default.
You need to insert  "-d"  to the follwing lines in /usr/lib64/sa/sa1 (or /usr/lib/sa/sa1) on a 32 bit system
        exec ${ENDIR}/sadc -d -F -L 1 1 -
        exec ${ENDIR}/sadc -d -F -L $* -

You also need to empty the current days database file /var/log/sa28 (<- day of the month)
the next time sar runs you should be able to run sar -d
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joolsAuthor Commented:
According to the man page, -A includes the `d` option....
where did you get it was turned off by default btw?

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martin_2110Commented:
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joolsAuthor Commented:
It does not match the man page information;

OPTIONS
       -A     This is equivalent to specifying -bBcdqrRuvwWy -I SUM -I XALL -n ALL -P ALL.

The sa2 command is specified in the cron job with the -A which should include the `d` option.

Running `sar -A 5 5` from the command line produces all the disk output, when it is run from cron under sa2 it is not. The man page for sa2 says in the description that it uses all the flags and options of sar.


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joolsAuthor Commented:
:-|

oh dear......


I was looking at the wrong line in the cron.d file.... it seems I should have been looking at sa1 which runs every 10 minutes and sa1 is the equivalent of sadc which does, by default, ignore disk stats.

sa2 does summat else and I'm so annoyed I really can be bothered to type `man` again.....

I think I'm getting too old for this stuff...

Thx

J
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joolsAuthor Commented:
Crontab added for future reference


# run system activity accounting tool every 10 minutes
*/10 * * * * root /usr/lib/sa/sa1 -d 1 1
# generate a daily summary of process accounting at 23:53
53 23 * * * root /usr/lib/sa/sa2 -A

Open in new window

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joolsAuthor Commented:
upping points cos I can :-)
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joolsAuthor Commented:
Not exactly my fix but did make me think. Upped points for helpfulness, grade B because...well.... because I'm old and grumpy!
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