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o By default, statistics are stored in the vCenter Server database for one year. You can increase this to three years. o You cannot view datastore metrics in the advanced charts. They are only available in the overview charts. o CPU Performance Enhancement Advice 1. Verify that VMware Tools is installed on every VM on the host. 2. Compare the CPU VCP-410 exam questions usage value of a VM with the CPU usage of other VMs on the host or in the resource pool. The stacked bar chart on the host's Virtual Machine view shows the CPU usage for all VMs on the host. 3. Determine whether the high ready time for the VM resulted from its CPU usage time reaching the CPU limit setting. If so, increase the CPU limit on the VM. 4. Increase the CPU shares to give the VM more opportunities to run. The total ready time on the host might remain at the same level if the host system is constrained by CPU. If the host ready time doesn't decrease, set the CPU reservations for high-priority VMs to guarantee that they receive the required CPU cycles. 5. Increase the amount of memory allocated to the VM. This decreases disk and or network activity for applications that cache. This might lower disk I/O and reduce the need for the ESX/ESXi host to virtualize the hardware. Virtual machines with smaller resource allocations generally accumulate more CPU ready time. 6. Reduce the number of virtual CPUs on a VM to only the number required to execute the workload. For example, a single-threaded application on a four-way VM only benefits from a single vCPU. But the hypervisor's maintenance of the three idle vCPUs takes CPU cycles that could be used for other work. 7. If the host is not already in a DRS cluster, add it to one. If the host is in a DRS cluster, increase the number of hosts and migrate one or more VMs onto the new host. 8. Upgrade the physical CPUs or cores on the host if necessary. 9. Use the newest version of ESX/ESXi, and enable CPU-saving features such as TCP Segmentation Offload, large memory pages, and jumbo frames. o Memory Performance Enhancement Advice 1. Verify that VMware Tools is installed on each VM. The balloon driver is installed with VMware Tools and is critical to performance. 2. Verify that the balloon driver is enabled. The VMkernel regularly reclaims unused VM memory by ballooning and swapping. Generally, this does not impact VM performance. 3. Reduce the memory space on the VM, and correct the cache size if it is too large. This frees up memory for other VMs. 4. If the memory reservation of the VM is set to a value much higher than its active memory, decrease the reservation setting so that the VMkernel can reclaim the idle memory for other VMs on the host. 5. Migrate one or more VMs to a host in a DRS cluster. 6. Add physical memory to the host. o Disk I/O Performance Enhancement Advice 1. Increase the VM VCP-410 study guide memory. This should allow for more operating system caching, which can reduce I/O activity. Note that this may require you to also increase the host memory. Increasing memory might reduce the need to store data because databases can utilize system memory to cache data and avoid disk access. To verify that VMs have adequate memory, check swap statistics in the guest operating system. Increase the guest memory, but not to an extent that leads to excessive host memory swapping. Install VMware Tools so that memory ballooning can occur. 2. Defragment the file systems on all guests. 3. Disable antivirus on-demand scans on the VMDK and VMEM (backup of the VM’s paging file) files. 4. Use the vendor's array tools to determine the array performance statistics. When too many servers simultaneously access common elements on an array, the disks might have trouble keeping up. Consider array-side improvements to increase throughput. 5. Use Storage VMotion to migrate I/O-intensive VMs across multiple ESX/ESXi hosts. 6. Balance the disk load across all physical resources available. Spread heavily used storage across LUNs that are accessed by different adapters. Use separate queues for each adapter to improve disk efficiency. 7. Configure the HBAs and RAID controllers for optimal use. Verify that the queue depths and cache settings on the RAID controllers are adequate. If not, increase the number of outstanding disk requests for the VM by adjusting the Disk.SchedNumReqOutstanding parameter. For more information, see the Fibre Channel SAN Configuration Guide. 8. For resource-intensive VMs, separate the VM's physical disk drive from the drive with the system page file. This alleviates disk spindle contention during periods of high use. 9. On systems with sizable RAM, disable memory trimming by adding the line MemTrimRate=0 to the VM's .VMX file. 10. If the combined disk I/O is higher than a single HBA capacity, use multipathing or multiple links. 11. For ESXi hosts, create virtual disks as preallocated. When you create a virtual disk for a guest operating system, select Allocate all disk space now. The performance degradation associated with reassigning additional disk space does not occur, and the disk is less likely to become fragmented. 12. Use the most current ESX/ESXi host hardware. o Networking Performance Enhancement Advice 1. Verify that VMware Tools is installed on each VM. 2. If possible, use vmxnet3 NIC drivers, which are available with VMware Tools. They are optimized for high performance. 3. If VMs running on VCP-410 questions the same ESX/ESXi host communicate with each other, connect them to the same vSwitch to avoid the cost of transferring packets over the physical network.