msa 1000 Throughput

[David Hills]

I have a msa1000 hooked to a BL20P via fiber and controller on active/active. I'm getting about 25Mb per sec both read and write at best (measure with iometer) If I do mixed on teh test it stays around 10Mb. It's Raid 10, windows 2003 enterprise. I can't figure out how to go forward tracking down where the trouble is. Any help would be greatly appreciated.

[Uwe Zessin]

The disks are the bottleneck. A RAID controller typically does not do spiral-transfers, so all great-looking numbers from single-drive performance tests are useless for a compare.

Some years ago I _was_ able to get about 80 MegaBytes/sec read I/O from a single MSA1000, but that was a special case:
running a host-based mirror-set comparison (using 127 block reads) on 5 or 6 MSA 2-drive mirrors at the same time and between two MSAs.

[David Hills]

So we get from 367Mb/sec theoretical limit all the way to no better than 25Mb per sec in the real world. That seems ridiculous. Searching the net I see people asking about their low performance on an msa1000 when they are getting much higher read speeds than me and a couple people talking about 70Mb sec writes measured with IOMeter. I'd really like to understand this better, but can't figure out how to use the tools to analyze the controller vs the disk array vs the server so see where the bottle neck is. Even if I can't change it I'd like to understand it better. Thanks

[David Hills]

Perhaps I should give some background. I'm a programmer who was given the job of building out a new blade server installation. I did the installation from uncrating the boxes to release for production myself. I have no prior experience doing this. Setting things up involved lots of googling and trying to make sense of various often conflicting (to me) recomendations. So I have a fairly reasnoable concern that I missed something basic in doing all this. I'm trying to prove to myself that I have things fairly optimal. There are a couple things I particularly wonder about. First block alignment. I tried to make things line up right wonder if I could have things so that it's often doing two reads to get a block or something like that. I also wonder if the controller is really set up right. I changed it to active/active but would like to verify that it's really using the two channels correctly. Seems like it's so easy to do something small wrong and really mess this up. Thanks again.