Help me spec a WAN accelerator server

[davidb1234]

Our full backup file of what we want to copy with a wan accelerator nightly is 150GB. It is all contained within 1 backup job.

We have a 100MB link between sites prod and DR.

How should I spec my wan accelerator VM to keep at least 2 copies of this off site DR environment?

I was thinking:
2 CPU core
4GB RAM
2008 R2 or Windows 2012 R2
500GB storage space

How taxing to storage is the WAN accelerator on the recieving side? Does it use a lot of IOPS?

[tsightler]

If you have a 100Mb link (I'm assuming that's what you meant, even though you used a big "B" instead of a little "b" since links are usually measured in bits, not bytes), and only 150GB for your full backup, then you don't need WAN accelerator unless you're looking to save the bandwidth. Remember that, after the first copy, it will pretty much only send changes anyway. Even for the whole file it will only take 4 hours for the full, your incremental changes will likely take less than 30 minutes unless you have a very high change rate.

To get any improvement at all you'll need SSD for the global cache and at least 8GB of RAM on both sides. Even then, performance will likely only be marginally faster than the 100Mb link. A very good, fast SSD can get you to perhaps 25MB/sec processing rate, but that only about 2x what you're getting already.

[Gostev]

Agree with Tom. We have designed WAN accelerators for WAN links slower than 100 Mbps.

[davidb1234]

Ok so no performance gain. Thats OK. HOwever we get charged for bandwidth so bandwidth savings will be important.

Also I found our link will be more likely between 200-400Mb not 100Mb.

Our delta files are 20-30GB and the full backup is 150GB.

So will 2 CPU cores, 8 GB RAM, 500GB storage space suffice for a setup like this? We will not be using SSDs or anything like that.

[Gostev]

If you are not planning to use SSD for cache, you have to reduce your cash size significantly. I recommend looking at no more than 50GB, otherwise it may become your biggest bottleneck. The rest of the spec matches the lack of cache performance, so this should be good enough.

[davidb1234]

Thanks for the tip. I didn't realize that the cache was so dependent on SSD. I will configure it for 50GB when we deploy the WAN accelerator.