Anyone with 4 x Samsung 840 PRO's on RAID5 with LSI Card?

serverian

New Member
Mar 24, 2013
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Hello,

I've searched a lot but could not find any benchmarks related to a setup that has 4 x Samsung 840 PRO's on RAID 5 array with a LSI 9265/9266/9271 card.

Anyone wants to share their benchmarks?

Thanks
 

supermacro

Member
Aug 31, 2012
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Just finished building some servers with four Samsung 840 Pro 512GB. I used Intel RS25DB080 which is the same as 9270-8i.













 

mrkrad

Well-Known Member
Oct 13, 2012
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4 unsupported Samsung 840 PRO with 9266-8i in raid 1+0 (10)

AS SSD (Esxi 5.1 - windows 2008 R2 guest, two vm's running at the same time , one on each controller/drive set)

1677.06 MB/S 815.05 MB/s
28.59 MB/s 48.48 MB/s
695.56 MB/s 263.49 MB/s
0.031 ms 0.073 ms


CDM 3.0.2 (same as above config)

1138 805
724.4 760.3
31.77 58.83
334.5 299.6

It seems that raid-5 has higher read (perhaps read caching enabled?) but the write amplification of raid-5 or raid-6 really turns me off! Same drives!

I can run the other tests - i'm too tired to post up graphics.

Keep in mind this is an older SINGLE IOHUB shared between two sockets (first vm is on socket-0 and second VM is on socket-1) 32 total lanes shared between both sockets of ole pci-e 2.0 ;)

Pretty darn good numbers for raid-5 I must say!
 

mrkrad

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Oct 13, 2012
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Changing from LSI SAS 16 QD to PVSCSI (default 32 QD, tunable to 255) improved CDM from 334/299 to 434/400 - This is because CDM is testing 32QD but the LSI SAS is hardcoded to 16 QD only. Buslogic is QD 1 and I think LSI PARALLEL is QD1 (reason to not use them!).

PVSCSI can be tweaked to QD 255 for heavy hitters pushing a ton of SSD in vm's!

I will go modify the PVSCSI to 255 QD and re-run the tests again and update
 

Andreas

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Aug 21, 2012
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I currently have 10 840 Pro (256GB) connected to one machine. The remaining 6 SSDs will arrive later today.
Currently connected to 2 x LSI 2308 HBA's.

Will provide some perf data later this week.

rgds,
Andy
 

Andreas

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Aug 21, 2012
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In the meanwhile.
4 x 256GB Samsung 840 Pro, connected to an LSI 9207-8i controller.
Raid5: via SW in WS2012



rgds,
Andy
 

renderfarmer

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Feb 22, 2013
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New Jersey
I currently have 10 840 Pro (256GB) connected to one machine. The remaining 6 SSDs will arrive later today.
Currently connected to 2 x LSI 2308 HBA's.
This is a n00b question but when you have two LSI controllers can you link them to form one giant spanned RAID array accross both?
 

Andreas

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Aug 21, 2012
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This is a n00b question but when you have two LSI controllers can you link them to form one giant spanned RAID array accross both?
Don't know about the Firmware capabilities of the controllers, but spanning Raids in the OS over multiple controllers is no problem. In Raid0, the 16 Samsungs deliver close to 8 GB/sec read and 7,2 GB/s write.

Andy
 

renderfarmer

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Feb 22, 2013
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New Jersey
Don't know about the Firmware capabilities of the controllers, but spanning Raids in the OS over multiple controllers is no problem. In Raid0, the 16 Samsungs deliver close to 8 GB/sec read and 7,2 GB/s write.

Andy
Thanks Andy. Does anyone know if two LSI 9271-8i cards will allow to span a RAID array accross both cards?
 

mobilenvidia

Moderator
Sep 25, 2011
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Thanks Andy. Does anyone know if two LSI 9271-8i cards will allow to span a RAID array accross both cards?
Nope, no spanning with LSI over controllers.
As above the OS can do it, but then you would need to
setup each drive as single RAID0, then let OS stripe the arrays
Or setup a X drive RAID0 array on each 9271 then let the OS stripe both arrays
 

mrkrad

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Oct 13, 2012
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Adaptec has 16 ports natively, this is why they are faster than 8 port LSI cards. The HBA is stupid cheap, but for SSD the 71605e is not bad price.

RAID 1/1E/10 - Raid 1E is like raid-5 without parity on odd drives. Even drives usually are just considered Raid 10(1+0) but don't have to be.

3 drive Raid 1E requires no crc/checksum , it just moves the blocks around like


1 2 3
3 1 2
2 3 1

Not sure if that's a good idea with SSD due to strip size but if you modified only one block, and the other blocks did not change, the SSD would probably disregard the write. Raid-10 is nice but does have similar write amplification with drive redundant block skips, raid-1 doesn't scale as much as-is but reduces write amplification of all 3.

16 SAS ports $370 [software raid] - question is - can you cross flash it? the 71605e has only 256 meg cache. I wonder what makes it jbod only since all Adaptec cards can do IT and IR at the same time.


Heck my old SAS 6/IR 1068E presents any non-raid non-spare drive as JBOD which was throwing me off since many LSI cards ban the feature out of the box.

I'd like to see a STH comparison of 71605q -> 9271 w/cc, 71605e -> LSI 2308, 71605h -> LSI 2308 . Or whatever is street price similar.

The hp OEM P420/1GB FBWC ($249 ! new ! limited deal ) kicked mucho butt. It outruns the 9266 w/fastpath+cc 2.0 and has its own cachecade 1 thats performs flawlessly with the same great UI.
 

Patrick

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Dec 21, 2010
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Adaptec has 16 ports natively, this is why they are faster than 8 port LSI cards. The HBA is stupid cheap, but for SSD the 71605e is not bad price.

RAID 1/1E/10 - Raid 1E is like raid-5 without parity on odd drives. Even drives usually are just considered Raid 10(1+0) but don't have to be.

3 drive Raid 1E requires no crc/checksum , it just moves the blocks around like


1 2 3
3 1 2
2 3 1

Not sure if that's a good idea with SSD due to strip size but if you modified only one block, and the other blocks did not change, the SSD would probably disregard the write. Raid-10 is nice but does have similar write amplification with drive redundant block skips, raid-1 doesn't scale as much as-is but reduces write amplification of all 3.

16 SAS ports $370 [software raid] - question is - can you cross flash it? the 71605e has only 256 meg cache. I wonder what makes it jbod only since all Adaptec cards can do IT and IR at the same time.


Heck my old SAS 6/IR 1068E presents any non-raid non-spare drive as JBOD which was throwing me off since many LSI cards ban the feature out of the box.

I'd like to see a STH comparison of 71605q -> 9271 w/cc, 71605e -> LSI 2308, 71605h -> LSI 2308 . Or whatever is street price similar.

The hp OEM P420/1GB FBWC ($249 ! new ! limited deal ) kicked mucho butt. It outruns the 9266 w/fastpath+cc 2.0 and has its own cachecade 1 thats performs flawlessly with the same great UI.
I could probably get the hardware (although don't have an Adaptec contact.) Might be at the point where I'd need help doing the testing.
 

0egp8

New Member
Apr 9, 2013
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Just finished building some servers with four Samsung 840 Pro 512GB. I used Intel RS25DB080 which is the same as 9270-8i.
In the meanwhile.
4 x 256GB Samsung 840 Pro, connected to an LSI 9207-8i controller.
Raid5: via SW in WS2012
It seems as though the 4kQD32 write throughputs of both of your setups are lower than what they ought to be.

This may be due to the controller not enabling the disk cache of your 840 Pros, as many have found that not doing so cuts performance drastically and possibly hinders garbage collection and wear-leveling. This issue is being discussed here:
Issues with 840 Pros for CacheCade? - Web Hosting Talk

Do you know whether the disk cache was enabled during your benchmarks?

To check, run the following command on MegaCLI:
"MegaCLI -LDGetProp -DskCache -LALL -aALL"
 

supermacro

Member
Aug 31, 2012
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Are you saying that there's an issue with Samsung 840 Pro as a Cachecade device or as a RAID set with 9270? Can you benefit or does anyone use Cachecade with straight SSD drives as RAID? I can see how I might want Fastpath for all SSDs but not sure if there's any benefit with Cachecade with all SSD RAID sets. I thought the Cachecade was for spinning drives...

Here is what I have with 9271-4i. Three Seagate ST3300657SS (300GB SAS 15K.7) with Samsung 840 Pro 512GB as Cachecade / cacheing device.

Disk cache was enabled on both VDs.










 
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klree

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Mar 28, 2013
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Are you saying that there's an issue with Samsung 840 Pro as a Cachecade device or as a RAID set with 9270? Can you benefit or does anyone use Cachecade with straight SSD drives as RAID? I can see how I might want Fastpath for all SSDs but not sure if there's any benefit with Cachecade with all SSD RAID sets. I thought the Cachecade was for spinning drives...
I think it is just an anti-LSI-ist
problem must be from LSI
 

mrkrad

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Oct 13, 2012
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samsung 840 pro's react to oem CDB commands by resetting. 830's don't. neither do sm843 - pro version of 840pro.