I have a challenging issue that I am facing and would like to lean on this community for advice and possibly answers to this issue.
We are running a dedicated server: Windows 2008 R2 64bit OS, 32 GB of RAM.
Our SQL Server version: MS SQL Server 2012 (11.0.3000).
Intermittently our server will drop to 0-5% CPU usage, during that time our applications have a hard time (or just cannot) connect to the SQL Server. Further, within the database logs I am reading this:
FlushCache: cleaned up 12007 bufs with 100094 writes in 130307 ms (ovoided 667 new dirty bufs) for db 7:0
last target outstanding: 4, avgWriteLatency 44
average throughput: 0.41 MB/sec, I/O saturation: 12161, context switches 25796
The above logs are written several times per day, however a few of these instances occur when our CPU drops to an extremely low rate. Our CPU for this server normally runs around 30-60% during business hours and I have never seen it drop to this level.
The only major changes have been an update in RAM from 16 GB to 32 GB. There were some updates to the maintenance backups, but those fire at 12AM (PST).
I am available to add any further logs or information and am extremely grateful for any help concerning this issue.