The title of the blog may be familiar to those who have ever used the TechBook (TB) on VMAX storage and VMware. Today we published the latest update to the TechBook:
The title of the TechBook has actually changed slightly – instead of “Symmetrix Storage” it is now “VMAX Storage”. EMC is moving away from the Symmetrix term when referring to the family of arrays that make up VMAX and VMAX3. Invariably, however, it will live on in other ways such as in product names, e.g. SRDF (Symmetrix Remote Data Facility). And speaking (or rather writing) of name changes, you won’t see the VMAX3 written with the superscript (VMAX3) in the TB any longer (assuming I didn’t miss any). I think eventually all EMC docs will use VMAX3 but in the meantime remember with or without the superscript it is the same platform.
I’ve made a few other minor housekeeping changes to the TB which I hope will be useful to customers. The first is to include the publication date on the front (seen above). When you download it, you can see the date on EMC.com or support.EMC.com but if you have the PDF somewhere on your system at least you won’t have to go back to the website. The second change is the removal of the list of tables and figures from the TB. I’ve pulled them from the SRA TB so it seemed logical to do it here too. The last change is in the Preface. I’ve added an IMPORTANT note which lists the VMAX code covered in the TB:
I think this is the most useful of the changes. For example there will be a new release later this year which will coincide with a new HYPERMAX OS version. If you download the TB after that date you at least will know if it is covered or not. Unfortunately the scope and breadth of the documentation I have to cover makes it difficult to publish concurrently with new releases so I do not expect another update to this book until December. I try to bridge the gap in time by publishing these blog posts and other whitepapers on the newer technology until I am able to update the TB. This way the information is out there, if not yet consolidated.
Well what’s new in this TB update then? The two biggest items are vSphere 6 and the latest VMAX3 release. You’ll see those changes throughout the TB. Other updated areas:
- VAAI – in particular XCOPY and eNAS
- VMAX CP for Log Insight
- Path handling (APD/PDL)
One notable change I will call out here is in the area of NMP and the IO Operation Limit (iops). We’ve made a distinction between the VMAX and VMAX3 when it comes to this parameter. For those not familiar with this limit, it represents the number of IOs that VMware will send down a particular path to the device before switching to the next path. EMC found a significant benefit in adjusting this value to ‘1’ on the VMAX so we did and do recommend making this change. Now initially we decided to leave this recommendation in place on the VMAX3 too; however the architecture from an FA perspective is very different between the VMAX and VMAX3. The TB explains the difference (CPU-based), but the bottom line is that switching after every IO might incur additional locking on the VMAX3. We therefore recommend setting iops to ‘4’ on the VMAX3. Do remember, however, that you can’t break anything. This is simply the best practice recommendation. So if you are currently using 1 on the VMAX3, don’t drop everything to make the change. Feel free to schedule the change at your convenience. If you happen to be using VMAX and VMAX3 on the same ESXi hosts you can change the parameter at the device level.
I’ll let you discover the rest of the changes. The new update is here (file name itself has not changed):
I’m always open to new areas to include in the TB if it makes sense so feel free to comment below. Thanks.