Unified Manager vs System Manager Overcommitted Different ?

[GROOVE]

Can anybody shed light on why Unified Manager and System Manager show quite different numbers for how overcommitted an aggregate is ?

All of our aggregates exhibit the same behaviour with UM reporting quite a bit more overcommittment on every aggr.

THe Avaialble space , Used space and Total space are all the same. But UM shows an overcommit of 45% and System manager shows 30% in the exmple attached

Is this a reporting error in one ofe the tools or am I overlooking something ?

[Sahana]

Hi,

It maybe due to a bug in UM. Refer the links below:

http://mysupport.netapp.com/NOW/cgi-bin/bol?Type=Detail&Display=815326
https://kb.netapp.com/support/s/article/ka11A0000001Mwz/oncommand-unified-manager-observed-aggregate-over-commit-warnings (needs login)

[GROOVE]

THanks for the reply

Unfortunately neither of those bugs seem to apply to what we are seeing,

All aggregates are showing is more overcomitted in UM compared to SM , but not by the sort of numbers eluded to in those bugs. It feels like UM is counting something else , or twice , or somthing odd as all the figures are showing about 20% or so more than SM.

[GROOVE · Accepted solution]

Logged with support and got this reply if antbody else is interested - 

The following kb explains the difference in committed space in OCSM and OCUM:
https://kb.netapp.com/support/s/article/ka11A0000001IuBQAU/oncommand-unified-manager-aggregate-commitment-calculation

So UM calculates overcommit by volume level taking into account the Maximum Auto-Grow size set on all volumes with it enabled as well. SM does not do this.

Hence the difference between the two tools.

Now to decide which measurement to 'use' 😉