VCP Question round up numero 1

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Question: What is the connection type of the primary VLAN in a Private VLAN?

Not sure how I got this one wrong but I guess I did.  The primary VLAN of the Private VLAN is promiscuous.  That is, it can talk to all  other members of the primary VLAN.  Members of the secondary VLAN can either be isolated (can only talk to the promiscuous ports) or community (talking to both promiscuous ports and other community ports on the secondary vlan). 

Question: An ESXi host is configured to access an iSCSI target using CHAP authentication.  What happens to the access if CHAP is disabled on the ESXi host?

The CHAP authentication is only used to make the initial connection to the iSCSI target.  Once that initial connection occurs, CHAP can be turned off and the connection will stay up.  If the connection needs to re-establish, and CHAP was still off, the iSCSI data store wouldn’t load. 

Question: To prevent non-ESXi hosts from seeing VMFS datastores, which would be the most efficient place to configure LUN masking?

LUN zoning is done at the hardware level and dictates what servers can talk to what LUNs.  Zoning can either be done by port (hard zoning) or by WWN (soft zoning).  LUN masking allows you to further restrict access between servers and LUNs and is generally done at the HBA level.  There are many reasons to mask certain LUNs from being presented including performance and windows volume issues.

Question: An administrator has a mixture of Intel-based ESX Hosts in a DRS cluster where the CPUs are compatible in every way except that some support the NX/XD feature and some do not.  Which two actions will minimize the effect of these differences? (Choose two.)

The NX (Never Execute)/XD (Execute Disable) bits are a type of security setting on processors.  All servers within a given cluster must have the same setting.  If some support NX/XD and others don’t, you’ll have to mask it on the ones that do.

Question: What is the maximum number of VMkernel swap files that an ESXi host can have on a single VMFS volume?

VMkernel swap files are per VM, not per ESXi host.  That being said, there is one per virtual machine. 

Question: An administrator must perform maintenance on a fibre channel switch connected to vmhba2 on an ESXi host. The ESXi host has been configured with the Fixed policy, and the preferred path will be impacted by the maintenance event.  Which procedure is the least disruptive option that can be taken to prepare for the maintenance event?

ESXi uses the following multi-pathing techniques…

Most Recently Used (MRU) — Selects the first working path, discovered at system boot time. If this path becomes unavailable, the ESX/ESXi host switches to an alternative path and continues to use the new path while it is available. This is the default policy for Logical Unit Numbers (LUNs) presented from an Active/Passive array. ESX/ESXi does not return to the previous path when if, or when, it returns; it remains on the working path until it, for any reason, fails.

Note: The preferred flag, while sometimes visible, is not applicable to the MRU pathing policy and can be disregarded.

Fixed (Fixed) — Uses the designated preferred path flag, if it has been configured. Otherwise, it uses the first working path discovered at system boot time. If the ESX/ESXi host cannot use the preferred path or it becomes unavailable, ESX/ESXi selects an alternative available path. The host automatically returns to the previously-defined preferred path as soon as it becomes available again. This is the default policy for LUNs presented from an Active/Active storage array.
Round Robin (RR) — Uses an automatic path selection rotating through all available paths, enabling the distribution of load across the configured paths.
For Active/Passive storage arrays, only the paths to the active controller will used in the Round Robin policy.
For Active/Active storage arrays, all paths will used in the Round Robin policy.

Note: This policy is not currently supported for Logical Units that are part of a Microsoft Cluster Service (MSCS) virtual machine.

Fixed path with Array Preference — The VMW_PSP_FIXED_AP policy was introduced in ESX/ESXi 4.1. It works for both Active/Active and Active/Passive storage arrays that support ALUA. This policy queries the storage array for the preferred path based on the arrays preference. If no preferred path is specified by the user, the storage array selects the preferred path based on specific criteria.

Note: The VMW_PSP_FIXED_AP policy has been removed from ESXi 5.0. For ALUA arrays in ESXi 5.0 the PSP MRU is normally selected but some storage arrays need to use Fixed. To check which PSP is recommended for your storage array see the Storage/SAN section in the VMware Compatibility Guide or contact your storage vendor.

That being said, the least disruptive action would be to disable the link on the ESXi host that was having service done on it. 

Question: What would cause the proportional share mechanism to be invoked?

The proportional share mechanism is what the resource manager process uses to allocate physical resource to VMs.  It keeps track of reservations and limits to make sure each VM is getting what it needs. 

Question: What is true about transparent memory page sharing?

Transparent memory page sharing is a mechanism in which ESXi reduces the number of memory pages by removing redundant copies.  When the redundant copies are removed the hosts that each had a copy of that memory page now share the memory page.  It is not recommended to disable this. 

Question: You are running into disk contention problems on a VMFS datastore. Which two actions will resolve this problem? (Choose two.)

Moving some virtual machines to a data store on a different LUN would help disk contention issues. 

Question: Which of the following actions requires a reboot of an ESXi host?

Changing the number of ports on an existing vSwitch. 

 

  

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