Active Active HA - Would appreciate your thoughts

[SE Data]

I'm working on a proof of concept/test for using Starwind as a SAN for our three host VMware cluster. We've been using SanMelody, but the next price jump is rather expensive compared to StarWind.

Current thoughts for the storage servers would be two of the below (we already own the servers, and would be buying the MD1000, disks, and 10GbE gear used):

Dell 2900's single E5520 CPU, with 16GB RAM
MD1000 connected via a PERC6 RAID card
15 - 400GB 10k SAS drives RAID 6 with 1 hot spare.
1 - 10GbE adapter, connected to the storage network.

Questions:

On my test server (6 - 72GB 15K SAS) it's maxing out around 110GB/sec for reads, and 60GB/sec for writes. The reads are obviously the limits of gigabit ethernet, why are the writes so low? Non HA I get the expected 110MB for RW. Should I expect similar write performance with 10GbE? Where is the bottleneck?

Can I swap the primary and secondary after they are setup?

Is the HA, active/active in that you can have an active LUN on each mirroring to its' partner, or active/active, in that each node can take a write at the same time and writes the data to the other node?

What is your experience with reliability? Is this thing bulletproof for serious production use where a minute of downtime is worth $100?

Thanks for your assistance in advance, if you have any other ideas where I might be off target or could improve please let me know.

Thanks!

--Jeffrey

[Max (staff)]

The Write procedure for the HA device is a bit different than read, It goes through both servers and handles the next write only after confirmation that the data is secure both on side A and side B. This shows an exact 120/2 without caching the writes. In order to get higher write speeds you need to enable write caching for the device.

Can I swap the primary and secondary after they are setup?

The active and passive only defines the priority of shutdown in case the sync channel breaks, in the upcoming release a switch will be available.

Is the HA, active/active in that you can have an active LUN on each mirroring to its' partner, or active/active, in that each node can take a write at the same time and writes the data to the other node?

The active-active means that the client can write to both nodes simultaneously if he can.

What is your experience with reliability? Is this thing bulletproof for serious production use where a minute of downtime is worth $100?

Of course it is! Using 10GbE network stuff and battery backed up cache makes it more agile and flexible than any good FC hardware.