OnCommand Unified Manager 9.5 "Capacity Logical"

[TMADOCTHOMAS]

I just upgraded to OCUM 9.5 and noticed a new feature that is supposed to appear on a volume page - specifically, it now includes data under "Capacity Physical" and "Capacity Logical". However, in my environment, I only see "Capacity Physical". I'm wondering if this is because of the OnTAP versions I run, currently 9.2 or 9.3. Is "Capacity Logical" something that only appears when I upgrade to 9.4 or 9.5? I'm asking ecause I want to use the "Logical Space Reporting" feature that is found under "Capacity Logical".

[Dhiman · Accepted solution]

Hi, 

You are correct. The ONTAP version should be at least at 9.4 for you to get benefit of this. This article may help you with the details you need to know : https://whyistheinternetbroken.wordpress.com/2018/06/11/logical-used-space-ontap94/

Thanks, 

Dhiman

[TMADOCTHOMAS]

Thank you @Dhiman! Very helpful. And actually, the article you posted made me realize the feature doesn't do what I thought it would do. I have been frustrated for a couple of years now that OCUM doesn't allow you to alert on actual volume size, but rather it alerts on potential size if you have autogrow turned on (we have autogrow turned on for all volumes). This makes for awkward custom percentages to force alerts to equal out to what we want it to be, and even then it relies on every volume to use autogrow caps at 20% (most have this, but sometimes during resizes it gets broken). I have been waiting / hoping for an OCUM update to fix this for two years now and thought this was finally it, but it's not. Do you have any insight on this issue? Is there a fix in the current version (when matched with a later OnTAP version) that I'm not seeing?

[john_weigand]

@TMADOCTHOMAS what do you have your percentages/thresholds set to? We have OCUM set perfectly to only ever alert if the volume has run out of autogrow room (no matter what it the max-autosize was) and then hits 70% full.

[TMADOCTHOMAS]

@john_weigand, we actually want to alert well before autogrow runs out so we can resize a volume before it reaches the 'end of the line'. Our philosophy is - we rely on autogrow to help fix the problem for a few minutes if we can't get to an alert immediately, but we want to resize the volume well before it reaches the autogrow cap.

With that in mind, for volumes under 500 GB we have alerts set to 68% and 76%, which equals out to 82% and 92%. For volumes over 500 GB they are set to 76% and 80%, which equals out to 92% and 96%. The fact that we have to do it this way is ridiculous to me, and confusing to those who manage alerts. They say, "why am I getting an alert when it's only 76% full?", when it's actually 92% full.

[Dhiman]

You can cap logical space through ONTAP logical space enforcements available with ONTAP 9.5 and monitor them with UM 9.5. Catch here is, ONTAP should be at 9.5 version. As you can see, we have enabled these in a phased manner,  in 9.4 we introduced logical space monitoring and in 9.5 we enhanced it with logical space enforcement so users cannot write beyond (written space + space savings). Hope this helps!

Details available here: https://docs.netapp.com/ontap-9/index.jsp?topic=%2Fcom.netapp.doc.dot-cm-sag%2FGUID-3B110CAA-5E40-4367-9CB3-DBCFE20F0B71.html&resultof=%22logical%22%2...

Best,

Dhiman  

[TMADOCTHOMAS]

Thanks @Dhiman !