19.

Understanding VMware’s Disk Types: Thin Disk vs. Thick Lazy Zeroed Disk vs. Thick Eager Zeroed Disk

When it comes to configuring your virtual environment, it’s very important that you select the right disk types for your needs or you could encounter outages, wasted storage or face lots of time on the back end reconfiguring your settings.

Thin Disk
This type of virtual disk allows you to allocate storage on demand, instead of deciding ahead of time how much space it’s going to take up. This is a good option if you want to control costs and scale out your storage over time. However, you need to pay closer attention to your disk size so you don’t overprovision and overcommit your storage to more than it can hold. Additionally, since it’s allocating on the fly, you might take some performance hits on initial writes that you wouldn’t encounter if you were to utilize one of its thick disk brethren options. This is because as new data space is allocated, the blocks have to first be zeroed to ensure the space is empty before the actual data is written.

You might also encounter some fragmentation on the disk when using this method, which can add to your performance degradation. This varies between storage types and vendors and how your array is set up.

Thick Lazy Zeroed Disk
If you want to pre-allocate the space for your disk, one option is to make a thick lazy zeroed disk. It won’t be subject to the aforementioned fragmentation problem since it pre-allocates all the space so no other files will get in the middle (which causes fragmentation), and it’s easier to track capacity utilization.

If you’ve got a clear picture of what space you’ll be using, like during migrations, for example, you may want to go with the thick lazy zeroed disk option. Also, if your backend storage has a thin provisioning option, more often than not you’ll want to go with this simply so you don’t have to monitor your space utilization in two locations. Managing thin provisioning and oversubscription on both the back-end SAN and on the front-end virtual disks at the same time can cause a lot of unnecessary headaches, as either or both locations can run out of space.

Thick Eager Zeroed Disk
Generally, we don’t utilize this option unless the vendor requires it. For example, Microsoft clusters and Oracle programs often require this in order to qualify for support.

When provisioning a thick eager zeroed disk, VMware pre-allocates the space and then zeroes it all out ahead of time. In other words, this takes a while — just to increase the net-new write performance of your virtual disk. We don’t frequently see the benefit in this since you only enjoy this perk one time. It doesn’t improve the speed of any of the innumerable subsequent overwrites. (In Hyper-V, by the way, this is called a fixed size disk.)
-----------------------------------------------------------
G E T M O R E C O N T E N T
----------------------------------------------------------
https://www.mirazon.com/thin-disk-vs-...
https://www.mavrickcloud.com/blogs/
https://github.com/maverick-cloud/
--------------------------------------------
S O C I A L M E D I A
--------------------------------------------
Facebook:   / maverick.cloud1  
Subscribe:    / maverickcloud  

Thanks for watching !! & for VMware, Storage, Amazon Web Services, Microsoft Azure and DevOps training, please reach me on [email protected]
#vSpherev67
#VMwareStorage
#VMwareFullTutorial