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Chris
Asked: 2010-10-25 06:35:09 +0800 CST

Method to calculate downtime percentage

  • 772

I need a calculation to work out the downtime percentage of a server.

I am making a script that runs via cron every minute to check the uptime of a remote server.

The two values I have to play with are number of checks run and times the checks failed (outages).

Is this a plausible way of calculating it? I am thinking it must be but can't be too sure as my Maths skills are slipping away from me with age!

uptime

3 Answers

  1. Best Answer

    Here's a simple spreadsheet layout to calculate and keep for historical purposes. You can set goals and apply conditional formatting to your hearts content.

      |   A   |         B        |       C      |      D       |     E
------------------------------------------------------------------------
1 | Month | Minutes in month | Minutes Down | Percent Down | Percent Up
2 | Jan   |            44640 |            1 | =(C2/B2)*100 | = 100-D2
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  2. Errrm, 100*failures/(failures+successes), or even simpler 100*failures/total-checks ?

    • 1

  3. Here's a modification of Ben's answer that doesn't need an ugly "Minutes in month" column.

      |   A   |       B      |      C                                               |     E
--+-------+--------------+------------------------------------------------------+------------
1 | Month | Minutes Down | Percent Down                                         | Percent Up
2 | Jan   |            1 | =(B2/(DAY(DATE(YEAR(A1),MONTH(A1)+1,1)-1)*1440))*100 | =100-C2
    • 0