Parameter question FSYNCS/SECOND

[sevo44]

The documentation says: "FSYNCS/SECOND value should be greater than 200 (you should enable write back cache mode on you RAID controller - needs a battery backed cache (BBWC))."

The no-load parameter has a value in the region of 600. When working on the parameter monitoring, I see a drawdown of up to 1. Is this a normal state or shouldn't the setting be so low?

 

[LnxBil]

The no-load parameter has a value in the region of 600. When working on the parameter monitoring, I see a drawdown of up to 1. Is this a normal state or shouldn't the setting be so low?

What is a "no-load" parameter and what is parameter monitoring?

The FSYNCS/second parameter is kind of a IOPS benchmark to the a raw and comparable number of your disk throughput. It does not reflect the overall storage performance, because this depends heavily on your use case. Nevertheless, if you run pveperf you should at least have 600 for a system you want to work with.

 

[sevo44]

No load when there are no virtual machines and monitoring values in Zabbix system. When you start virtual machines, the value drops to a minimum and then reverts back. Is that okay?

 

[fabian]

No load when there are no virtual machines and monitoring values in Zabbix system. When you start virtual machines, the value drops to a minimum and then reverts back. Is that okay?

this is not something that you are supposed to run/monitor continuously.. it's just a quick check to get a ballpark number. of course if you put load on a storage and benchmark at the same time, your benchmark results will be worse (not matter whether it's a real benchmark, or just pveperf).

 

[sevo44]

Good. Thanks for the replies.