Term
| If you are constantly seeing high CPU host usage or VM CPU ready values above 20%, what steps can you take? |
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Definition
* Verify VMware tools is installed on every VM on the host
* Compare the CPU of all VMs on the host or resource pool using a stacked bar chart
* Determine whether high ready time is resulting from a CPU limit and if so, increase the limit
* Increase the shares to give the VM more opportunities to run. If the host ready time doesn't decrease, increase CPU reservations for high priority machines
* Decrease the number of vCPUs
* Increase memory allocated to VM. This should in turn decrease disk and network activity for apps that cache.
* If the VM is not in a DRS cluster, add it to one. If it is, increase the number or hosts or migrate one or more VMs off the host
* Upgrade the physical CPUs or cores on the host
All suggestions here from mike preston's blog blog.mwpreston.net |
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Term
| If you are constantly seeing high or low memory usage or free memory is consistently 6% or less and swapping is occurring, what steps can you take? |
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Definition
* Verify that VMware tools is installed. The balloon driver is included with the tools and is critical to performance.
* Verify that the balloon driver is enabled
* Reduce the memory space on the VM and correct cache size if it is too big
* If reservations is set to a value much higher than it's active memory, decrease this reservation so the vmkernel can reclaim the idle memory for other VMs
* Migrate one or more VMs to another host
* Add physical memory
All suggestions taken directly from Mike Preston's blog: blog.mwpreston.net |
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Term
| What steps would you take to configure or modify a NIC adapter for a VM? |
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Definition
| In vSphere client, right click the VM and select 'edit settings'. Go to the Hardware tab and select the appropriate NIC in the HW list. Select an option for MAC address configuration of the NIC. Configure network Connection for the virtual NIC. |
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Term
| What options do you ahve for MAC address configuration on a virtual NIC? |
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Definition
1. Automatic: vSphere assigns an address automatically
2. Manual: Type the MAC address to use |
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Term
| What counters can you watch in ESXTOP to determine te workload of your VM application in order to determine appropriate datastore locations? |
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Definition
CMDS/s – Number of IOPS being sent to or coming from the device or VM.
DAVG/cmd – Average response time in milliseconds per command being sent to the device
KAVG/cmd – amount of time the command spends in the VMkernel
GAVG/cmd – response time as it is perceived by the guest OS. (DAVG + KAVG)
Taken from blog.mwpreston.net |
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Term
| What characteristics would you expect from High Tier/Tier 1 storage? |
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Definition
Offers high performance and high availability. Might offer built-in snapshots to facilitate backups and point-in-time restorations. Supports replication, full SP redundancy, and SAS drives. Uses high-cost spindles
Source: virtuallanger.com |
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Term
| What characteristics would you expect from Mid Tier/Tier 2 storage? |
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Definition
Offers mid-range performance, lower availability, some SP redundancy, and SCSI or SAS drives. May offer snapshots. Uses medium-cost spindles
Source: virtuallanger.com |
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Term
| What characteristics would you expect from Lower Tier/ Tier 3 storage? |
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Definition
Offers low performance, little internal storage redundancy. Uses low end SCSI drives or SATA
Souirce: virtuallanger.com |
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