We are looking at switching from our current HP MSA SAN which is fiber channel to a Dell SCv3020 SAN. I have some questions that maybe someone here can help answer.
We were looking at doing a SAS attachment to three hosts in a ESXi environment (mainly for cost savings). These would be stood up beside our current hosts so we could migrate them one at a time and do testing before full moving and decommissioning of the old servers.
Are there anything we should be aware of with direct SAS attachment compared to our old Fiber Channel setup? Any pros or cons? Our current FC environment is only 8Gbit so moving to 12Gbit is already one plus.
In the deployment document it says VMware vSphere is not supported on servers connected to the storage center over SAS. what exactly does this mean? We current use vSphere in our FC environment, does this mean vSphere running on a server that is attached via SAS or not able to use vSphere at all?
I also was wondering about the RAID levels... I'm a little bit confused, I'm used to RAID0, 1, 5, 6, 10, 5+0, 6+0 etc... Dell calls it RAID 5-5, RAID 5-9, 6-6, 6-10 what is different about these? Do I have to have a RAID array with a fixed number of disks? Like RAID5 must have 5 or 9 disks? Can someone clear this up for me.
Replication wise, we were thinking about adding another SCv3020 at some point and replicating it via iSCSI to an off site location. Are there any issues with having direct attached SAS setups then using iSCSI for replication?
We are also wanting to have encrypted storage, obviously we need an encryption license and self encrypting drives.. is there any pros or cons to doing this at the hardware level as opposed to doing it at the ESX level with encrypted virtual drives?
As for ESX hosts, when they are attached via SAS how does a VM failover work? With Fiber channel its pretty much seamless since everyone on the fabric can be set up to see the LUNs.. how do you handle this with SAS or can you?