Wall Clocks Lie

Lonny Niederstadt digs into some strange behavior on one of his VMs:

Rats.  That was a really good idea, too.  Nothin’.  Or….
(I want to call attention to the change in maximum axis value for CPU utilization.  I nearly *always* use 100% as the maximum value, In these last two graphs I’ve used a maximum value of 24% because utilization of each of the 4 vcpus is really low and I felt it made the graphs slightly more readable.)
Hey!! Perfmon was collecting 30 second samples.  But two intervals after 2:06:22 is 2:07:52 rather than 2:07:22.  The system lost 30 seconds in the span of a minute.  And two intervals past 2:07:52 is 2:11:22 – the system lost 150 seconds in a minute?

It would appear that there are a couple of issues with this box, one of which is a lack of appreciation of the current time.

Related Posts

Version Store and ONLINE Operations

Josh Darnell takes us through how SQL Server manages ONLINE = ON operations (such as index building and rebuilding) using the version store: The votes table has about 10 million rows in it, so this takes a bit of time (10-15 seconds if nothing else is happening). If I check sys.dm_tran_version_store_space_usage and sp_WhoIsActive, I can see that: – […]

Read More

Starting SQL Server in Single-User Mode

Ranga Babu has a few methods for starting SQL Server in single-user mode: It is advisable to use SQLCMD when you want to query SQL Server that is started in single user mode as connecting directly and query using SQL Server Management Studio that uses more than one connection. To query SQL Server single user […]

Read More

Categories

February 2017
MTWTFSS
« Jan Mar »
 12345
6789101112
13141516171819
20212223242526
2728