I'm starting to build out my C6100 chassis and kind of getting annoyed with how much RAM costs for 8GB and beyond.
I'm also starting to realize that clustering one C6100 chassis with all 4 nodes in a MSFT Failover Cluster is pointless if you don't have hosts with enough memory available to receive the migrations or check the heartbeat.
Unfortunately this kind of puts a weird dent in my original plan: to have 3 C6100 chassis each used for different hyperconverged implementations, where at least 1 is "home-prod" that has a consistent environment that doesn't change(this was to be 1 C6100 chassis with 4 nodes in a ScaleIO setup). The other 2 chassis would be used to test other technologies and do development.
If I have 4 C6100 nodes in a single chassis that are each hosting individual VMs then it's likely that their memory usage will be at near cap at some point. This means migrating to other nodes in the same chassis wouldn't be possible. So it means I need to have replication targets setup in a separate chassis or additional hosts available in the cluster that aren't really running VMs(so they have the RAM available) ready to receive the migrations. This gives me one less set of nodes to experiment and play around with.
I am wondering, what kinds of strategies or policies do you guys have at home or in the workplace for this? Do you just make sure that your RAM usage/allocated amount never passes a specific threshold or is the industry practice to have empty hosts on hot-standby ready to receive migrations?
I guess another main issue is that the C6100 nodes only have 12 DIMMs, so you can only do 48GB of RAM if you go with 4GB sticks, 96 if you get 8GB, and 192 if you get 16GB sticks. This wouldn't be an issue if 16GB sticks were cheap(er/ish) since I don't think I would ever come close to utilizing 192GB RAM per node. So it limits me to 48/96GB for now.
In anticipation of some possible questions, right now I don't really see myself using a lot of RAM for a load of VMs since you don't need to allocate much memory to things like AD, but, I definitely was planning on implementing a SharePoint farm based on MSFT's requirements(which range anywhere from 12 to 24GB of RAM based on the server) since I've started doing a lot of SP development.
Thanks for your input! (I am sure this same question applies to pretty much any clustered virtualization environment so VMware folks, XenServer, Nutanix, etc, please feel free to chip in!)
I'm also starting to realize that clustering one C6100 chassis with all 4 nodes in a MSFT Failover Cluster is pointless if you don't have hosts with enough memory available to receive the migrations or check the heartbeat.
Unfortunately this kind of puts a weird dent in my original plan: to have 3 C6100 chassis each used for different hyperconverged implementations, where at least 1 is "home-prod" that has a consistent environment that doesn't change(this was to be 1 C6100 chassis with 4 nodes in a ScaleIO setup). The other 2 chassis would be used to test other technologies and do development.
If I have 4 C6100 nodes in a single chassis that are each hosting individual VMs then it's likely that their memory usage will be at near cap at some point. This means migrating to other nodes in the same chassis wouldn't be possible. So it means I need to have replication targets setup in a separate chassis or additional hosts available in the cluster that aren't really running VMs(so they have the RAM available) ready to receive the migrations. This gives me one less set of nodes to experiment and play around with.
I am wondering, what kinds of strategies or policies do you guys have at home or in the workplace for this? Do you just make sure that your RAM usage/allocated amount never passes a specific threshold or is the industry practice to have empty hosts on hot-standby ready to receive migrations?
I guess another main issue is that the C6100 nodes only have 12 DIMMs, so you can only do 48GB of RAM if you go with 4GB sticks, 96 if you get 8GB, and 192 if you get 16GB sticks. This wouldn't be an issue if 16GB sticks were cheap(er/ish) since I don't think I would ever come close to utilizing 192GB RAM per node. So it limits me to 48/96GB for now.
In anticipation of some possible questions, right now I don't really see myself using a lot of RAM for a load of VMs since you don't need to allocate much memory to things like AD, but, I definitely was planning on implementing a SharePoint farm based on MSFT's requirements(which range anywhere from 12 to 24GB of RAM based on the server) since I've started doing a lot of SP development.
Thanks for your input! (I am sure this same question applies to pretty much any clustered virtualization environment so VMware folks, XenServer, Nutanix, etc, please feel free to chip in!)