topic Re: EVA6000 write speed over 180MB/s ? in Disk Enclosures

EVA6000 write speed over 180MB/s ?

Jan Soska — Fri, 10 Jun 2011 10:58:37 GMT

Hello all,
we are doing some tuning tests on our older EVA6000. As we already knew, write speed could peek max 180MB/s due 2Gbit connection between eva controllers (say design feature).
For some reason, we created raid0 vdisk and our tests are big surprise - on disk group with 28 15K 136GB drives we reached 360MB/s write (with write cache enabled) and 260MB/s (with write cache disabled). See screenshot.
Any ideas how it is possible?

Re: EVA6000 write speed over 180MB/s ?

Sivaramakrishna_1 — Sat, 11 Jun 2011 05:15:49 GMT

Hi,

that 180MB/s is a single port bandwidth. If you have multipathing solution the IO will pass through all the ports, so max bandwitdh will be 180MB*4 (As EVA 6000 will have 2 ports per controller). Hope this may be the situation in your case!!!

Siva...

Re: EVA6000 write speed over 180MB/s ?

Patrick Terlisten — Sun, 12 Jun 2011 08:20:17 GMT

Hello,

360 MB/s can be reached by using two host-ports. If you're using MPIO it will distribute the load over all active and optimized paths.

Regards,
Patrick

Re: EVA6000 write speed over 180MB/s ?

Jan Soska — Sun, 12 Jun 2011 09:22:40 GMT

hello,
maybe I am wrong,
but have we can reach this in 1 single 2Gb pipeline between controllers? And why other raids like r10 do not perform the same way?
I think it is not multipath related,
I'll test it on other server without mpio.

jan

Re: EVA6000 write speed over 180MB/s ?

Patrick Terlisten — Sun, 12 Jun 2011 15:01:33 GMT

360 MB/s with a single pathed EVA?! Sure that the EVA isn't an EVA6100?

Regards,
Patrick

Re: EVA6000 write speed over 180MB/s ?

Jan Soska — Sun, 12 Jun 2011 15:28:10 GMT

Yes, I am pretty sure, HSV200, 6240 firware.
I can't believe my eyes, that's why I'm asking how it could be... :)

Jan

Re: EVA6000 write speed over 180MB/s ?

Sivaramakrishna_1 — Mon, 13 Jun 2011 03:38:53 GMT

Hi,

The "HSV 200" you are observing from Command View EVA??? or the Physical Plastic Bezil of the Controller.

Why because, there are 3 models of HSV 200 controllers.

HSV 200 - 2Gb Port speed
HSV 200-A - 4Gb port speed
HSV 200-B - 4Gb Port speed(4100/6100)

All the models will be appeared as only HSV 200 in Command view EVA!!!!

Re: EVA6000 write speed over 180MB/s ?

Jan Soska — Mon, 13 Jun 2011 05:58:45 GMT

Hello,
it is just normal HSV200, with 4Gb hosts port, and as I know, 2Gb mirror connection.
So, pretty interesting.

Jan

Re: EVA6000 write speed over 180MB/s ?

Sivaramakrishna_1 — Mon, 13 Jun 2011 06:04:33 GMT

Hi Jan,

It is sure that if the host port speed is 4Gb, either the controller would be HSV200-A or HSV200-B.

The initial model of this EVA was only with 2GB Host port, where as the Device and Mirror port speeds are 2Gb for all models.

If the host port speed is 4Gb then there is no surpise in getting 360MB/s...

Re: EVA6000 write speed over 180MB/s ?

Uwe Zessin — Mon, 13 Jun 2011 07:59:22 GMT

A HSV200 controller module (even the first generation) has TWO mirror ports.

Re: EVA6000 write speed over 180MB/s ?

Jan Soska — Mon, 13 Jun 2011 08:11:08 GMT

Uwe - direct hit, checked manually in server room. No it makes sense to reach 360MB with 2x2Gbit mirror port.

Btw - we can not go over 180MB/s with r10 writes. Is it becouse r10 takes more bandwith (like each write goes to 2 disks -> 2x180MB/s)?

Jan

Re: EVA6000 write speed over 180MB/s ?

Uwe Zessin — Mon, 13 Jun 2011 08:26:25 GMT

Sounds reasonable.
The HSV200 has two loop ports to the disks. A VRAID-10 write requires twice the bandwidth, because the data goes to two disk drives.

In that case the second mirror port doesn't help, because cache mirrored data need to be replicated only once.

Re: EVA6000 write speed over 180MB/s ?

Jan Soska — Mon, 13 Jun 2011 11:25:16 GMT

New record, after understanding Uwe's post I created 2 raid10 luns on the same disk group, presented to 1 win servers (each lun on different controller), created dynamic disk (stripped) and bingo - 420MB/s read, 230MB/s write.

Nice.

Jan

Re: EVA6000 write speed over 180MB/s ?

Jan Soska — Mon, 13 Jun 2011 13:42:11 GMT

Uwe helped