As we know common opinion is that Fibre Channel is for data center and iSCSI is for small and medium sized business. Actually this belief is WRONG. Choosing if you want to use Fibre Channel of iSCSI is a lot more complex than that.

Performance

When we will look at this matter focusing on performance, we can notice that iSCSI made a very big steps in improving data transfers in past year. Now we can use even 10Gb Ethernet while Fibre Channel can use 8Gb. Soon we will be able to see improvements as big as 40 to 100Gb on iSCSI and 16 to 32Gb on Fibre Channel.

Another important matter except transfer speed is latency. Although iSCSI on 10Gb Ethernet can carry more data than 8Gb Fibre Channel, it also benefit from lower latencies!

Decision

If you would like to choose if you are either going for FCoE or iSCSI you would need to think about those four main reasons:

1. Data center strategy
2. Performance needs
3. Desire for compatibility
4. Cost concerns

It all depends on for what you would like to use your network any answer isn’t perfect one. In some cases FCoE will be cheaper then iSCSI but in some cases quite the opposite.

iSCSI is more easier to implement since hardware and software drivers are available for nearly every operating system. That makes it a great choice for new storage networks.

FCoE is more focusing on evolution on already existing Fibre Channel storage networks. Least popular type of building Fibre Channel network is end-to-end FCoE SAN but in near future that type will be the most commonly used.

Final Decision

FCoE is a new evolution of already existing Fibre Channel networks and it is suitable for companies that already own Fibre Channel equipment. On the other hand it is still under development therefore some features may be unreliable.

iSCSI is a proven technology that can be adapted to in any Ethernet network without any additional costs (if you would like to use software iSCSI Targets). It is also easier to manage since many administrator already know Ethernet networks.

Which one is better? It all depends on your current and future needs.

Source:
http://goo.gl/4hKQc


iStorage Server - Software iSCSI Target:
http://www.kernsafe.com/product/istorage-server.aspx
(Free version also available.)

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Using LUN infrastructure you can easily improve your virtual machine performance. You just need to remember about disk types, I/O and RAID levels when creating LUNs.

For medium and large networks ranging from 100 to 1000 VMs there are several ways to increase performance of VM. Usually best option is RAID 5 configuration along with SAN with two to four controllers, large disk cache and 10Gb iSCSI.

This will provide a good balance of virtual machine performance and cost for production workloads.

For small or test networks with less than 100 VMs administrators struggle with LUN configuration. That is because virtual infrastructure is growing faster than they anticipated and administrator have unrealistic I/O expectations.

Keeping that in mind - local storage, low-end direct-attached SCSI or iSCSI SAN with SATA drives can work well. In small or test networks where CPU and disk cache have smaller usage, try to implement RAID 10 to get additional boost in VM performance.

Depending on hardware you have, anywhere from 4 to 15 virtual machines per LUN is reasonable, but if you will assign more than your network can handle, I/O of disk will be biggest bottleneck.

It's crucial to keep that in mind - if you will have large number of CPU cores and memory unused, those resources will go to waste since I/O will limit their usage.

Source:
http://goo.gl/R6pte

Did you ever wonder how you can make your virtual machine more optimized? Here are 10 tips that will help you achieve it in no time!

1. Update Hardware

Updating hardware by swamping old technology with new one is obvious step in optimizing your virtual machine. But this time this refers to updating BIOS of your hardware. That may help you avoid any unnecessary downtime and can prevent any security breaches.

2. Full Licenses

This may not necessary change how well your machine will work but by purchasing full licenses can unlock features that are not available in free versions.

3. Separate Network

You should always keep in mind that virtual machines can use big portion of your network therefore you should create a separate network just for this matter.

4. Separate Disk Images

Usually when you create multiple virtual disks for one virtual machine, all those disks are keep together on the same disk array. If you will keep them separate it will result in faster disk response.

5. Limit vCPUs

This may sound a little bit odd but in real life scenarios limiting number of virtual processors available for use for VM can increase its performance. It is that its decreases wait time for host resources.

6. Thin Provisioning

It is always a good idea to use thin provisioning on storage. It will result in more efficient storage utilization and will move all processing related with storage away from the virtual infrastructure.

7. Separate Service Levels

Again, this it’s obvious but not everyone do it. You should separate your VM service levels. This should be done logically and physically so each environment differs from each other.

8. Virtual Machine Names

Sounds so simple yet so effective. If you will use logical VM instead of for example VMW7SP01, VMW7SR01, VMW7SS01 it will be a lot easier to manage them and administrators won't make any mistakes while patching or repairing them.

9. Templates

Using templates can easily increase efficiently while creating new VM. It will speed up the whole process of creating new VM significantly and will also save time on patching or installing software.

10. Host Profiles

Mainly used in VMware, is a concept of host profiles. Using those profiles an administrator can setup host system more efficiently and will greater consistency.


Hopefully all those tips will help you to optimize your VM and increase its overall performance.

Source
http://goo.gl/40qTh