Good all the time of day.
Briefly describe the hardware configuration:
3 host VMWare Esxi (Servers IBM)
1 store IBM DS 4700
2 FC Switch IBM System Storage SAN24B-4 Express (Brocade 300)
2 hosts are connected to the storage.
As the system is used for monitoring Veeam One.
Now let us briefly about the problem:
Occasionally get errors about "losing" storage, ie wheels off for a few seconds and connect again.
Also it is accompanied by increased delays to 250-750 milliseconds.
The problem occurs on two hosts at once, almost simultaneously.
Extract from log Esxi:
Device naa.600a0b800050beaa00000b0350af1498 performance has deteriorated. I / O latency increased from average value of 5900
microseconds to 275685 microseconds. warning
Just look at the number of lost words FC switches on the ports where the attached storage. The numbers are quite large about 1 million, but it's over a long period of time off including authorized hosts.
Also on our VMWare received advice that is sometimes required to expose certain fill word on ports Switch, I would like to clarify where this option is set, and what is required for my situation?
Also in the time of the error in the section esxtop disk devices were recorded as follows:
Parameter FMBRD / s periodically raised from 0 to 214
In the next cycle parameter DAVG / s rising to 6000
After 5 minutes, the problem has moved to the next stage
Parameter DAVG / s rose only to 500
Entire period QUED option for some devices equaled 34, ACTV - 30,% USD 100 respectively.
After another 5 minutes the problem went away.