VMware 4817V62 Administration Guide - Page 333

Appendix C Performance Metrics Table C-3. Disk Data Counters (Continued) Entity Counter Label Description VHR C kernelWriteLatency maxTotalLatency numberRead Kernel Disk Write Latency Average amount of time, in milliseconds, spent by VMKernel processing each SCSI write command. n Stats Type: absolute n Unit: millisecond n Rollup Type: average n Collection Level: 2 n VC/ESX: Yes/Yes ο•ο ο Highest Disk Latency Highest latency value across all disks used by the host. Latency measures the time taken to process a SCSI command issued by the guest OS to the virtual machine. The kernel latency is the time VMkernel takes to process an IO request. The device latency is the time it takes the hardware to handle the request. Total latency = kernelLatency + deviceLatency n Stats Type: absolute n Unit: millisecond n Rollup Type: average n Collection Level: 1 n VC/ESX: Yes/Yes ο•ο ο Disk Read Requests VM Number of times data was read from each virtual disk on the virtual machine. ••ο ο Host Number of times data was read from each LUN on the host during the collection interval. numberWrite Disk Write Requests n Stats Type: delta n Unit: number n Rollup Type: summation n Collection Level: 3 n VC/ESX: Yes/Yes VM Host Number of times data was written to each virtual disk on the virtual machine. Number of times data was written to each LUN on the host during the collection interval. ••ο ο queueLatency Queue Command Latency n Stats Type: delta n Unit: number n Rollup Type: summation n Collection Level: 3 n VC/ESX: Yes/Yes Average amount of time spent in the VMkernel queue, per SCSI command, during the collection interval. n Stats Type: absolute n Unit: millisecond n Rollup Type: average n Collection Level: 2 n VC/ESX: Yes/Yes ο•ο ο VMware, Inc. 333