New to ISCSI need help

[chrisBrindley]

As of yesterday we are going away from a data domain setup using CIFS, to a Nexsan which uses ISCSI for our default repository.
I have setup the storage on the main veeam console, setup ISCSI initiators and can see the storage in windows and veeam.

The question i have for anyone that has used it, do the proxy servers need to be setup with ISCSI initiators and have a drive appear in there disk management, or is it one of those magical veeam things where they just know how to talk to the repository.

[tsightler]

When using traditional storage the server to which you've presented the iSCSI volume should be configured in Veeam as a repository server. At that point, once you select that repository for a job, the proxies will send the data to that server to be written to the repository.

[chrisBrindley]

Tom, what scenarios are possible on the backup repository for the Proxy servers to write directly to the storage, is it NFS and CIF only.
We have 16 Proxy servers and if they all have to write their data through the veeam console to the iscsi repository its going to bring it to a crawl because i am assuming this would be across the Network between hosts

[tsightler]

I certainly wouldn't recommend using the Veeam console as the gateway to the repository. Repositories can be deployed to any Windows or Linux machine, both virtual and physical. The repository receives the compressed data streams from the proxies and writes the files.

Proxies can only write directly to a repository via CIFS/SMB, however, even here traffic goes over the network, as obviously these are network protocols. Also, for any given job, only a single server actually sends data via CIFS/SMB, the other proxies being used by that job must send their datastreams to this server, which acts as the "gateway" to the CIFS/SMB device. Also, since you're using iSCSI, that's also using the network as well.

Obviously you could carve up your storage and present it as 16 different repositories to the 16 proxies, but I doubt you'll want to do that. Typically, the better option is to dedicate a server as a repository. Ideally this server would have an interface dedicated to iSCSI, and a separate interface to receive the traffic from the proxies, this way the backup traffic flows in from the proxies, and out through the iSCSI interface thus providing optimial data flow. I personally like this server to be physical, but you can certainly use a virtual server as well. Remember that it needs to be sized to handle all of the incoming backup streams, generally it's fairly light on CPU, but I suggest at least 2GB of RAM per stream.

Also, you have 16 proxies, and assuming they are 4 vCPU each that means you have the potential to have up to 64 simultaneous backup streams, which is a lot and you'll need to size the repository server appropriately. You may find it's better to carve out two repositories, and have two repository servers and split your jobs between them, but that's based more on the size of your repository, disk count, etc.