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We are trying to track down performance problems on our server, and when running SPA or the performance monitor the counter for "File Control Bytes / Sec" sometimes skyrockets, typically about once every 10 minutes. For example, here were the 10 most recent readings:


Could the spikes be impacting our I/O performance (we are noticing users infrequently needing to wait a long time to access files)? Also, what exactly is File Control Bytes/Sec (beyond the unclear definition from MS: "all file system operations that are neither read nor write operations, including file system control requests and requests for information about device characteristics or status") ... do we need to worry about it?


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That doesn't look healthy - are you seeing very high interrupts/sec too? Is this server connected to a SAN or is there just local storage? – Helvick Feb 9 '10 at 15:36
Just local storage ... do you know exactly what data transfers are included in this counter? Not sure about interrupts / sec, just added it to the list of counters being watched. – Beep beep Feb 9 '10 at 15:53
The description is accurate if a little vague - at least as far as I understand it - it describes the non data traffic related to things like SCSI bus rescans\resets and handling any other storage related interrupts. – Helvick Feb 9 '10 at 16:06
According to the O'Reilly book "Windows 2000 Performance Guide": "This counter measures the total number of bytes transferred for all filesystem operations that are not reads and writes. This includes bytes retrieved from the cache, so this is not necessarily load imposed on the disk." - so this could even be nothing, depending on your actual disk activity counters. – MattB Feb 9 '10 at 18:19
up vote 0 down vote accepted

We moved our Active Directory backup to another server and this problem was resolved.

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