Book Image

Mastering Zabbix (Second Edition)

Book Image

Mastering Zabbix (Second Edition)

Overview of this book

Table of Contents (18 chapters)
Mastering Zabbix Second Edition
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Index

Understanding the levels of IT service


Availability is directly tied with service level and is normally defined as a percentage. It is the percentage of uptime over a defined period. The availability that you can guarantee is your service level. The following table shows what exactly this means by considering the maximum admitted downtime for a few of the frequently used availability percentages:

Availability percentage

Max downtime per year

Max downtime per month

Max downtime per week

90% called one nine

36.5 days

72 hours

16.8 hours

95%

18.25 days

36 hours

8.4 hours

99% called two nines

3.65 days

7.20 hours

1.68 hours

99.5%

1.83 days

3.60 hours

50.4 minutes

99.9% called three nines

8.76 hours

43.8 minutes

10.1 minutes

99.95%

4.38 hours

21.56 minutes

5.04 minutes

99.99% called four nines

52.56 minutes

4.32 minutes

1.01 minutes

99.999% called five nines

5.26 minutes

25.9 seconds

6.05 seconds

99.9999% called six nines

31.5 seconds

2.59 seconds

...