Question: Datastore - Added 2nd drive, is it being used or only after 1st is full?

[GasparYYC]

Hi everyone.
 I'm kicking the tires of ESXi v6.5 free on my old-ish server. My intention is to create a handful of WMs.

Background:
When I installed ESXi 6.5 (due to processor compatibility) I noticed the datastore just had 1 drive, later I added the 2nd drive to the single datastore.

Question:
Will the space on the 2nd drive be used after the all space on Drive 1 is used? or Is the space is agreggated and everytime I write a file or create a VM the data is split in both, essentially doubling the thoughput ?

For ease I have included a screenshot that shows both drives in use (agragated space is 2.72TB)


Thanks in advance

-G

[zeroboy · Accepted solution]

If you add a second drive (or partition) to your datastore, it will do concatenation, meaning it will used as soon as your first drive is filled up. No striping is happening. There's a nice blog article from Cormac Hogan from 10 years ago 😎

VMFS Extents – Are they bad, or simply misunderstood? 

[GasparYYC]

That article helped me understand better whats going on.

Thanks!