How long to quick format a lun in Windows

 I always get that question for the SQL or file cluster RDM disks.  Windows admin and DBA thought the format hung but it indeed took long time to quick format a lun.  Last week, Windows admin complaint it took approx an hour to quick format a 7TB lun in EMC PMAX for a Windows 2016 / 2019 VM.  

I just completed a test this morning.  For a physical Windows 2016 server, it took about 10-15 min approx to quick format a Windows 1 TB lun in PMAX.  Do some research in the internet.  The result provided by partitionwizard.com suggests it indeed takes long time to format a big lun (see below also).  

• How Long Does It Take to Format a 1TB Hard Drive: Performing a Quick Format on a 1TB hard drive takes about 20 minutes. If you select the Full Format, it could take you up to 1 hour.
• How Long Does It Take to Format a 2TB Hard Drive: Again, we perform a Quick Format on a 2TB hard drive, it can be done in about 30 minutes. However, a Full Format can take up to 3 hours. If this hard drive stores a chunk of data, it could take you a half day.
• How Long Does It Take to Format a 4TB Hard Drive: To a certain degree, 4TB is a large hard disk that will take quite a long time to format. So, you’d better select a Quick Format if you want to save time. This is because fully formatting a 4TB hard drive can take you a whole day and even more

This give you an idea even quick format in Windows will still take some time.  

Our Wintel team will test the format time following EMC article 000062689 on the PMAX.

The cause is "trim and unmap" feature is on.  So, just temp turn it off before formatting new lun and enable it back once done.  

On the windows host, disable the SCSI TRIM and Unmap feature for the duration of the format. Use fsutil command from the command line

1) To verify the current setting, using a Windows CMD window on the Host, run:   

fsutil behavior query DisableDeleteNotify

DisableDeleteNotify=0 -indicates the 'Trim and Unmap' feature is on (enabled)

DisableDeleteNotify=1 -indicates the 'Trim and Unmap' feature is off (disabled)

2) To disable, issue the command:   

fsutil behavior set DisableDeleteNotify 1

3) Once formatting is complete, re-enable the feature using command:   

fsutil behavior set DisableDeleteNotify 0

It may impact Linux as well.  See thread mkfs is extremely slow. 

To run mkfs without trim, use the -K option on XFS and -E nodiscard on ext4

XFS

mkfs.xfs -K /dev/sdx 

EXT4

mkfs.ext4 -E nodiscard 

Warning: Only use -K or -E on new volumes with no existing data.

Using the -K or -E options on drives with existing data, will cause the space to be wasted until the data is overwritten.