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H310 performance problems
I posted a message in the the storage community forum but not sure if that was the best place for it. http://en.community.dell.com/techcenter/storage/f/4466/p/19480687/20249968.aspx#20249968
Anyhow, I have done some additional testing and I think I need to have my drives hooked up in a different way or have a different/additional drive controller.
I have an R720xd with 12 x 2TB SAS drives in the front and a pair of SSD in the back. They are all hooked up to an H310 and are setup as non-RAID in the bios.
In my testing of sequential throughput with dd if I am writing to one of the SSDs the performance is as expected (almost 400MB/s) however as soon as I also write to one of the spinning drives the throughput drops to 140MB/s on the SSD to match that of the spinning disk. There is still headroom on the CPU so I think this is different than my other posting referenced above. If I write to both SSDs they average over 370MB/s each. So basically I am loosing some of the benefit of having an SSD when writing concurrently to one of the spinning disks.
I am guessing I would benefit from having a separate controller for the SSDs. Thoughts on this? I am thinking I would keep the SSDs on the current H310 and then move the others (front backplane) to a different controller. Any suggestions on which controller which might help me get around the issue from my other post (or is that a not enough CPU problem)? I hear there is an IT firmware that can be applied to LSI based cards would this be of benefit to me for the 12 drives (I am not going to use hardware raid). Should I go for a PERC H200 since that supposedly is already in IT mode?
thanks.
One other question...does this problem apply to the H310 adapter also or only the integrated one?
All versions of the H310 to my knowledge.
It will be able to easily max out what your drives are capable of. It has 8 ports that are capable of 6Gb/s for a total throughput of 48Gb/s(~6GB/s). If your account team has any questions for me then have them search the corporate directory for Daniel_My. I'm the only one that will show up.
http://www.dell.com/downloads/global/products/pvaul/en/dell-perc-h710-spec-sheet.pdf
Thanks
So I had a look inside finally and the rear backplane uses a standard SAS connector. Do you know if it is possible to connect this to the SW raid SAS connector on the motherboard? Is that connector active if an integrated RAID card is installed?
This could mostly solve my problem of the performance degradation that my SSDs are suffering while being connected to main backplane. If they are separate then I am ok with my HD raid maxing out at 400-500MB/s if this means the SSDs are not impacted.
theflash1932
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Posted July 5th, 2013 08:00
The H310 supports JBOD, but the H710 does not.
Not sure if any of the newer firmware updates fixed anything.
If you really want JBOD get a Dell 1U system with a separate drive enclosure and use an LSI card (the Dell SAS HBA card may work too) . I don't think it is worth the headache to try making the R720xd work in JBOD.
I ended up sucumbing to the Dell way and setup HW RAID using a H710P (they were nice enough to swap the cards at no cost). I am using the SSDs for CacheCade.
theflash1932
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Posted July 5th, 2013 11:00
Yes, they have a 6Gbps SAS HBA as well ... those ARE Dell's proposed solutions for JBOD. I'm with create ... if you want JBOD, I'd go third-party too.
create123
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Posted December 14th, 2012 10:00
Hmm... don't like the sounds of that.
Anyhow I decided to check out the performance of the H310 with RAID 10 (6 spans of 2 PD per span) and dd maxes out at just under 400MB/s. I was doing slightly better with JBOD and software RAID. I am in the process of creating 3 different RAID 0 of 6, 4 and 2 drives to see how those perform. So far can't say I'm happy about this setup.