Solved

LSI MegaRaid 9240-8i

Posted on 2014-03-03
6
2,206 Views
Last Modified: 2014-04-06
Hi Experts,
I have SuperMicro computer with LSI 9240-8i card and eight WD40EFRX drives.
There is RAID 5 volume with 64KB strip size over all eight drives.
I have current firmware, current driver, operating system is Windows Server 2012 R2.

Problem is write performance at all. Sequential write is 18MB/s. I think that is caused by my wrong setup, I could not believe performance of that card is that bad, any cheap piece of RAID crap performing much better.

That card cannot setup write or read cache, there are "no read ahead" and "write through" enabled and cannot be changed - as far as I believe.

Sequential read rate is about 350MB/s which is pretty good - it is far much for my needs...
0
Comment
Question by:Vanikcz
  • 3
  • 3
6 Comments
 
LVL 30

Expert Comment

by:pgm554
ID: 39901757
Does that card have any cache at all?

I don't see any in the manuf spec.

And if I remember correctly ,you need an onboard battery to be able to turn on the cache anyway.

No cache ,sucko performance.
0
 
LVL 6

Author Comment

by:Vanikcz
ID: 39902547
No there is no cache, but it is 8 disks. If I have just one it will be far faster than that... 18MBps in sequential write, thats very lazy, I cant believe that!
0
 
LVL 30

Expert Comment

by:pgm554
ID: 39903621
Cache makes all the difference and you are running RAID 5 on top of that.

I never buy a hardware RAID controller for a file server without cache.

There are lots of folks that get a rude awakening thinking that an external RAID controller will be faster,it's faster,but only with battery backed cache.

I would try RAID 10 if you are married to that controller.

If you are adventurous,you could try RAID 1 for boot disks and set the other disks up as JBOD.

Then use the JBOD disks to set up REFS.

http://msdn.microsoft.com/en-us/library/windows/desktop/hh848060%28v=vs.85%29.aspx
0
Highfive Gives IT Their Time Back

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

 
LVL 6

Author Comment

by:Vanikcz
ID: 39907126
I had post that problem on LSI support... I just wont believe in such that lazy performance, Im not expecting rates as from expensive card, but 18MBps of sequentilar write is really too low.
I had try cheapest Silicon Image card with four disks and I had results about 60MBps... on RAID5
0
 
LVL 30

Accepted Solution

by:
pgm554 earned 500 total points
ID: 39907175
Your limitation here is your raid controller.

Random writes like a large cache, and parity-based RAIDs like a fast parity calculator.

The more disks you add to a parity-based RAID array (like RAID 5 or 6) on a locally attached controller, the lower performance you'll see per spindle. Large direct attached storage (above 8 drives or so) tends to be raid 10 to avoid this issue.

 The only reason to use parity based RAID (5 or 6) is to benefit from a higher ratio of usable space.

The downside is that if you lose a drive, the rebuild will take more time if the RAID was a large one.

You can also try this:

Bring up the property page for your raid disk and select Policies.

Make sure that both Enable write-caching is on and also select "Turn off Windows write-cache buffer flushing on the device".
0
 
LVL 6

Author Closing Comment

by:Vanikcz
ID: 39981082
That controller is not good for RAID5, thank you all for clarify that
0

Featured Post

Enabling OSINT in Activity Based Intelligence

Activity based intelligence (ABI) requires access to all available sources of data. Recorded Future allows analysts to observe structured data on the open, deep, and dark web.

Join & Write a Comment

Bellevue, WA, USA; Late December, 1980 "OK, folks, we nailed the IBM contract. We're going to have many meetings like this to discuss features and functions...and how to move from 86-DOS, the CP/M clone we just purchased, to our baby, MS-DOS. Thi…
More or less everybody in the IT market understands the basics of Networking, however when we start talking about Storage Networks, things get a bit dizzier, and this is where I would like to help.
This video Micro Tutorial explains how to clone a hard drive using a commercial software product for Windows systems called Casper from Future Systems Solutions (FSS). Cloning makes an exact, complete copy of one hard disk drive (HDD) onto another d…
When you create an app prototype with Adobe XD, you can insert system screens -- sharing or Control Center, for example -- with just a few clicks. This video shows you how. You can take the full course on Experts Exchange at http://bit.ly/XDcourse.

747 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now