Comments on: Administering a VMAX-3 series system ? A few things you have to consider..

By: Vividh

Vividh — Thu, 01 Sep 2016 07:57:21 +0000

Really appreciate your efforts in bringing these major differences between the next gen VMAX array code features

By: Vijay

Vijay — Sun, 06 Sep 2015 07:57:03 +0000

In reply to admin. Thanks for correcting me Vipin!! You are absolutely correct. VMAX3 looks very robust in terms of capacity utilization and offering a great application level performance.

By: admin

admin — Fri, 04 Sep 2015 20:21:15 +0000

In reply to Vijay. Hi Vijay, Thanks for your note. Coming to your query, you are right that the track size is now 128KB (not 64KB) with VMAX-3. But the extent size is still 128KB as the allocation unit is 1 track only with VMAX-3 series systems. You may refer the page 9-10 in VMAX-3 new features for further clarification. Regards, Vipin V.K

By: Vijay

Vijay — Fri, 04 Sep 2015 11:06:22 +0000

Hi Vipin,

Appreciate your time in posting a lot valuable information in your blog!!

Coming to this post, as you have mentioned below as:

“And the thin device extent is 128KB (improved granularity from 768KB in previous models).”

If i’m not wrong, as per the calculation i know, 1 extent = 12 Tracks and each track in VMAX earlier generations is 64 KB(8 sectors, 1 sector=8KB), so it comes in total 1 extent size= 12*64 KB = 768 KB which you have mentioned is correct for the older VMAXs models BUT

Since the VMAX3 has an increased track size which is 1 track=128 KB(16 sectors, 1 sector=8KB),
as per the extent calculation above, 1 extent size = 12 tracks = 12*128 KB = 1536 KB.

Is my assumption correct!!!