40 TB Media Server Performance issues

A

ashrafi

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Jan 17, 2011
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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.
Syncing was completed ( Raid6 was configured , Initialized & build , I installed 2008 R2 after )
I let the computer run for 2days (free run) and now i am trying to test it ,
I have done following tests.

Transferred 3.4Tb files over the network ( I know N.W traffic and BW will cause issues )
Transfered 240 gb from external drive ( USB BW bottle neck )
Transfered 500 Gb files locally between ( 2Tb Raid 1 OS dirve to Raid 6 Storage drive )

All three tests indicated Write speed way higher ( 315Mb/s in local transfers) and slowly degraded to only 30-35Mb/sec.
This shows the limiting factor is somewhere in the hardware setup itself( assumption)
Secondly The maximum Write speed for Caviar Green is 84Mbps ( I should atleast get 70mbps).

I chose GPT for Storage drive due to OS limitations and 16Kb allocation size, The stripe Cache is 512Kb.
Maybe Striping is making it as slow ... dont know!!
 
Is your controller set to write-through mode?

Can you tell us whether your partition is aligned? You can check with AS SSD (works fine on your RAID) just open it and select your raid volume; it will say OK for good alignment and BAD for misaligned partition.

Posting the AS SSD benchmark for your RAID would also be very helpful.
 
What is the 2Tb OS drive connected to? (perc or onboard)

Once the local bottleneck is resolved, consider getting an Intel network card, Realtec's are know to have issues under load.
 
Does your PERC 6/i have a battery attached? If not, I don't think it will allow write-back to be enabled. Additionally, connect your source computer and media server directly and bypass your network switch, then run the network transfer again. Also, make sure you have jumbo frames configured on the network adapters.

Question: how did you get the PERC 6/i to see more than 8 physical drives? Last I heard, they weren't capable of it. Did you flash it with LSI firmware?
 
This is a double-post from Anandtech, but old controller, 20xGreen drive RAID 6, and throw in a SAS expander generally makes for poor write performance.
 
Are you really talking about megabits per second (Mb/s, Mbps) or are these supposed to be megabytes per second (MB/s)?

Make sure your partition is aligned to the RAID chunk size, this can degrade performance significantly. Do you have an Intel gigabit NIC lying around? If yes, try that. I generally have no bad experience with Realktek based NICs, but your mileage may vary. The write speed for a single drive is not a good indicator for a 20 drive RAID. Please also check the read speed. Moreover, the throughput reported by Windows is not a very good performance indicator.
 
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Unless I missed it, I didn't see what kind of files you were moving. Was it one large file or a bunch of small ones? Also, what's your network speed?
I too had an issue with my transfer speeds degrading over the course of the transfer. I had forgotten to load the drivers for my RAID card and was simply relying on the drivers Windows gave it. I loaded the correct drivers and all was well.
 
@omniscence , I am talking about MB/s , I am using realtek Gigait Nic however at the moment ,I am simply transferring files between 2 VDs , and tryingto find maximum performance .
I am doing some tests i will post results soon,( will use Bigfoot Killer to test and Cross Cable test )

@sub.mesa , AS SSD works , will post results , but I am totally unaware of this alignment thing , I understand and it makes sense too but how can I test it on the raid , and is there any other software for fixing it / testing it.
I found following article , http://support.microsoft.com/kb/929491
but I have always used Diskpart on fresh drives , would the following method work on my already set Raid ,
<create partition primary allign=xxx >
Help me with this alignment thing!
@parityboy, Yes my friend ! everything is set as you have mentioned , Battery attached and Write Back configured.

@Adi , OS is separate 2 Tb VD in Raid 1 , however connected to same Controller.

Primarily I am trying everything for local bottlenecks to be resolved.! Network optimization comes after.
 
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