Hello, ive taken over a new NetApp Env. We have 2 FAS3240's running 7-mode version 8.2.3.
Ive found there are a nice chunk of volume with Dedupe scheduled on them. However its really not doing anything for us as some of these volumes are setup on a one to one basis. Meaning, we have a 1TB Volume, then a 1 TB LUN created from that Volume, and in Vmware the entire 1 TB LUN is used to create a 1 TB Datastore. There is no thin provisioning on the Volumes or Luns. There are also no snapshots being used. So Deduping isnt doing anything for us on these type of volumes as vmware will never see this extra free space.
So I turned Dedupe off on a couple Volumes, I dont see the need to have it keep working to run dedupes every night which can cause a small performance hit.
So on these Volumes that ive turned Dedupe off, my understanding is that the volume is still deduped it just wont dedupe any new data going forward. I guess my first question is that correct?
My next question is, by keeping that Volume in that state, is there a performance hit on it, even if its small? Im assuming if someone requests data from a block that has been deduped, it first has to look up where that block is located in the dedupe table which is more overhead. Is that correct?
Im asking becuase im wondering if I should UnDedupe these volumes? Give the controllers a little less work to do
If so, is there anything i should watch out for? Im assuming its smart enough to not run out of space while undeduping? Or is that not the case and my volumes might run out of space when I Undedupe?
For the most part we have free space on the Volume, but im wondering if there should be a certain percentage i need free to undedupe. For instance i have one Volume that is roughly 1 TB, The Vmware Datastore is only using about 750 Gigs of actual Data, so technically there is 250 Gigs free from the Vmware side of things. The Dedupe has shrunk the volume allot, I dont remember the number but I think its around 60% free. Once i Undedupe the Volume will have no free space which is fine.
Im just a little nervouse about Undeduping, im going to look into a little more on what its doing in the background first
Thanks for any input