40 TB Media Server Performance issues

[ashrafi]

I have build a media Server with following specifications,
Gigabyte GA-H55-UD3h motherboard
Processor i5 680
Dell Perc 6i Raid Card
Chenbro Expander
20 * 2Tb Western Digital Caviar Green in Raid 6 configuration
I have set Intellipark to 300secs as discussed on some forums , After installing Server 2008 R2 I transferred 3.4Tb data on the raid setup and it took 3 days . (The maximum speed reached is 30Mbps).I have set the cache block size to 512mb . I believe the speed if extremely slow , I made sure the raid card was installed in the x16 pcie slot , I might be missing something , how can I increase the performance of this media server or is it bottle neck due to hardware itself.

 

[lowfat]

Well I have no experience w/ SAS expanders. What RAID are you using? Have you looked to see how it performs compared to other PERC6i's when using that many disks? It is only just a 400MHz ROC. If you are doing a RAID5/6 w/ that many drives I don't expect it to perform all that well.

 

[ashrafi]

I am using Dell perc 6i Raid and Chenbro expander , it is meant for Dell Servers and definitely supports 40Tigs , I am not sure how to test the performance or factors limiting Raid 6 performance , neither do I have reference from someone who had atleast tried high capacity storage and benchmarked its read and write speeds!

 

[lcdguy]

also keep in mind that several users (not necessarily on this forum) have expressed issues and a strong dislike with WD green drives due to the power management which is built into the drive which can cause issues with RAID configurations. Especially Raid Levels 5 and 6. but i wish you all the luck on this.

 

[ashrafi]

Oh yes , The WD Intelli Park feature was causing issues as the drives would fail and fall out of raid , but i enabled th intellipark to max , and now everything seems to work fine.

 

[tangrisser]

I'm not sure how it would work but have you checked hard drive alignment using WD Align?

 

[ashrafi]

I have not done 4k alignment (only XP ???) as i thought it wasn't necessary in Raid configuration , Block Size and Cache Stripe are more relevant , and I am using GPT partition ( Allocation size = 16K ).

 

[ashrafi]

40Tb Raid

Flickr: Owais11's Photostream

Test REsults

 

[MikeFallen]

you could try rebuilding the raid array is raid 10 (two raid 5 arrays in raid 0) iv heard it gets pretty good numbers

 

[lcdguy]

Raid 10 get's great performance but also would half the amount of storage space. It's also great for database servers due to the number of individual disks. Also raid 10 is not raid 5 in a raid 0 configuration. Raid 10 is multiple striped sets mirrored in a volume. As such there is no parity so there is less cpu overhead and the potential for disk failures without data corruption is much higher with raid 10.