Search the VMware Knowledge Base (KB)
View by Article ID

Formatting disks on VMware VSA nodes takes longer than expected (2000573)

  • 0 Ratings


When selecting the Format disks immediately option during the VMware vSphere Storage Appliance (VSA) Installer, the operation can take longer than expected to complete.


This issue relates to both the SCSI/RAID controller as well as the physical drives. The Format disks immediately option writes zeroes to every block, which means that the entire region is written to. While this improves write performance, it can also take significantly longer to complete.

The amount of time this operation takes entirely depends on the amount of IOPS the underlying hardware can do. Since controllers and disks are all different, use an IOPS calculator (such as to determine the expected completion time.

When you have your throughput value, divide the total size of the calculated space by the throughput value and then divide by 60 to get the value in minutes.

It is important to note the IOPS capability of this hardware setup when deciding whether or not to place a high disk I/O virtual machine on the VSA. This can lead to poorer than expected performance. That is, do not put a SQL server that requires 2500 IOPS when the underlying hardware can only issue 1500 IOPS.



Request a Product Feature

To request a new product feature or to provide feedback on a VMware product, please visit the Request a Product Feature page.


  • 0 Ratings

Did this article help you?
This article resolved my issue.
This article did not resolve my issue.
This article helped but additional information was required to resolve my issue.

What can we do to improve this information? (4000 or fewer characters)

Please enter the Captcha code before clicking Submit.
  • 0 Ratings