Category Archives: HA

SQL Server HA and DR

SQL Server 2012:
http://msdn.microsoft.com/en-us/library/jj215886.aspx
AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution by Using Failover Cluster Instances and Availability Groups
Failover Clustering and AlwaysOn Availability groups (http://msdn.microsoft.com/en-us/library/ff929171.aspx)

Client panel for AlwaysOn AGs: http://channel9.msdn.com/Events/TechEd/NorthAmerica/2013/DBI-B318#fbid=yIkpgRpThsW

AlwaysOn Architecture Guide: Building a High Availability and Disaster Recovery Solution by Using AlwaysOn Availability Groups
SQL Server 2012 AlwaysOn: Multisite Failover Cluster Instance
Failure Is Not an Option: Zero Data Loss and High Availability
EMC Solution: http://www.emc.com/collateral/hardware/white-papers/h10546-sql-server-2012-multisite-dr.pdf
AlwaysOn requirements:  http://technet.microsoft.com/en-us/library/ff878487.aspx

SQL Server 2008:
Proven SQL Server Architectures for High Availability and Disaster Recovery
Using Replication for High Availability and Disaster Recovery in SQL Server 2008

High Availability with SQL Server 2008 R2:
http://msdn.microsoft.com/en-us/library/ff658546(v=sql.100).aspx?ppud=4

High Availability and Disaster Recovery (DW):
http://technet.microsoft.com/en-us/library/hh393561.aspx

Availability %

Downtime per year

Downtime per month*

Downtime per week

90% (“one nine”)

36.5 days

72 hours

16.8 hours

95%

18.25 days

36 hours

8.4 hours

97%

10.96 days

21.6 hours

5.04 hours

98%

7.30 days

14.4 hours

3.36 hours

99% (“two nines”)

3.65 days

7.20 hours

1.68 hours

99.5%

1.83 days

3.60 hours

50.4 minutes

99.8%

17.52 hours

86.23 minutes

20.16 minutes

99.9% (“three nines”)

8.76 hours

43.8 minutes

10.1 minutes

99.95%

4.38 hours

21.56 minutes

5.04 minutes

99.99% (“four nines”)

52.56 minutes

4.32 minutes

1.01 minutes

99.999% (“five nines”)

5.26 minutes

25.9 seconds

6.05 seconds

99.9999% (“six nines”)

31.5 seconds

2.59 seconds

0.605 seconds

99.99999% (“seven ¬† nines”)

3.15 seconds

0.259 seconds

0.0605 seconds