VMware VCP-410 Exam

o Perform a rescan each time you make one of the following changes:
o Create new LUNs on a SAN.
o Change the path masking on a host.
o Reconnect a cable.
o Make a change to a host in a cluster.
o Change CHAP settings or add new discovery addresses.
o If you notice unsatisfactory performance for your software iSCSI LUNs, you can change their maximum queue depth by using the vicfgmodule
o The iscsi_max_lun_queue parameter is used to set the maximum outstanding commands, or queue depth, for each LUN accessed through the
software iSCSI adapter. The default is 32, VCP-410 exam questions and the valid range is 1 to 255.
o Setting the queue depth higher than the default can decrease the total number of LUNs supported.
Appendix A – iSCSI SAN Configuration Checklist
o Set the following Advanced Settings for the ESX/ESXi host:
o Set Disk.UseLunReset to 1
o Set Disk.UseDeviceReset to 0
Appendix B – VMware vSphere Command-Line Interface
o The resxtop command provides a detailed look at ESX/ESXi resource use in real time.
o The vicfg-iscsi command allows you to configure software or hardware iSCSI on ESX/ESXi hosts, set up CHAP parameters, and set up
iSCSI networking.
o Use the vicfg-mpath command to view information about storage devices, paths, and multipathing plugins.
o Use the esxcli corestorage claimrule command to manage claim rules. Claim rules determine which multipathing module should
claim paths to a particular device and manage the device.
o The vmkping command allows you to verify the VMkernel networking configuration.
Appendix C – Managing Storage Paths and Multipathing Plugins (Same as Appendix B in the Fibre Channel SAN Configuration Guide)
Resource Management Guide
o The need for resource management arises from VCP-410 study guide the over-commitment of resources.
o Resources include CPU, memory, power, storage, and network resources.
o The guide focuses primarily on CPU and memory. Power resource consumption can also be reduced with the Distributed Power Management
(DPM) feature.
o ESX/ESXi manages network bandwidth and disk resources on a per-host basis, using network traffic shaping and a proportional share
mechanism, respectively.
o Shares specify the relative priority or importance of a virtual machine (or resource pool).
o Shares are typically specified as High, Normal, or Low and these values specify share values with a 4:2:1 ratio. (or can set Custom value)
o A reservation specifies the guaranteed minimum allocation for a virtual machine.
o The reservation is expressed in concrete units (megahertz or megabytes).
o Reservation defaults to 0.
o Limit specifies an upper bound for CPU or memory resources that can be allocated to a virtual machine. It never gets more than this.
o A limit is expressed in concrete units VCP-410 questions (megahertz or megabytes).
o CPU and memory limit default is unlimited.
o Using limits can be beneficial if you want to manage user expectations, but might waste idle resources.
o Expandable Reservation defines whether reservations are considered during admission control.
o Overhead Reservation is the amount of the “Reserved Capacity” field that is being reserved for virtualization overhead.
o Worst Case Allocation is the amount of (CPU or memory) resource that is allocated to the virtual machine based on user-configured resource
allocation policies (for example, reservation, shares and limit), and with the assumption that all virtual machines in the cluster consume their
full amount of allocated resources.
o Admission Control – If enough unreserved CPU and memory are available, or if there is no reservation, the virtual machine is powered on.
Otherwise, an Insufficient Resources warning appears.
o ESX/ESXi cannot enable hyperthreading on a system with more than 32 physical cores, because ESX/ESXi has a logical limit of 64 CPUs.
o Hyperthreaded Core Sharing Modes:
o Any – can freely share cores with other virtual CPUs.
o None – each virtual CPU should always get a whole core to itself, with the other logical CPU on that core being placed into the halted
o Internal – cannot share cores with vCPUs from other virtual machines. Can share cores with the other virtual CPUs from the same virtual
machine. Only for SMP virtual machines.
o For the best performance, when you use manual affinity settings, include at least one additional physical CPU in the affinity setting to allow at
least one of the virtual machine’s threads to be scheduled at the same time as its virtual CPUs.
o Dynamic Voltage and Frequency Scaling (DVFS) – You can configure your hosts to dynamically switch CPU frequencies based on workload

Leave a Reply

Your email address will not be published. Required fields are marked *