Slower parity speeds with WD Caviar Green drives?

[jeller316]

I have been having slow speeds on my parity check for awhile replaced my mobo but had same problems. Finally I decided to take a look at the 2 new drives I added both are TB WD caviar green drives 16mb cache. Model WD10EACS. With these 2 drives in my unraid along with some others I was getting on average 2.4 mbs which it would take about 3 days to do a check. I took one of these drives out of the array and still have slow speeds then of course took the other out and swapped them but still no better. If I take both of them out of the array and put in my old WD 500gb drive as parity my speed jumps up to 17-20 mbs. Has anyone else had this problem? It seems to be related to both drives. I did a search on the forum and it looks like other people have had success with this drive.

 

There is no jumper on the drive so it should be sata 2. If the mobo isn't sata2 should I put the jumper on?

 

Any help or suggestions would be great. Thanks in advanced.

[erikatcuse]

This is from another post after I noticed a slower parity check.  Telnet into the server or run the following from the console.  Try this for just the two WD drives and if you want check your other drives as well.

 

I started searching the net and I'm not sure if I found the complete problem but I think NCQ is the issue.  I don't know if this is a chipset problem, a motherboard not being able to support NCQ or a driver issue but when I turned off NCQ I saw a huge performance increase. First make sure you're in AHCI mode and then disable NCQ with the following. 

 

To turn off NCQ do the following for each disk

 

echo 1 > /sys/block/sdX/device/queue_depth

 

you can than use

 

cat /sys/block/sdX/device/queue_depth  to see if it was set.  So if you get a number greater than 1 it is enabled if its a 1 its disabled.

[jeller316]

Thanks for the help I will try this but I am so dumb when it comes to linux is there a how to for a newb?

[PsyVision]

FYI: My parity drive is the same as yours except it is the version with 32MB cache, I also have a data drive the same.  My parity check ran at 55MB/sec last night.

 

To run the commands that erikatcuse suggested, just type them at the console when your unRAID server has booted (once you are logged in ofcourse).

[jeller316]

I tried typing in the commands like they are shown but it says it is an unknown file or directory. Do I need to substitute something to tell it which drive to look at?

[erikatcuse]

yes you'll need to find your drive assignment letters.  To do that go to the devices page on your towers website.  From there you will see the drives listed.  It will look similar to this

pci-0000:00:1f.2-scsi-3:0:0:0 (sde) ata-WDC_WD10EACS

  What your looking for is the 3 letters in parenthesizes, in this case its (sde) and  substitue those for the sdX

[jeller316]

Thanks for the info I looked at all my drives the 2 WD that were in queston came up as a 1 but 2 of my other drives showed up as a 31. Now all come up as a 1 this is what I want correct? started a parity check and now my speed is 1.4 mbs!!! It got a little worse. Any thoughts?

 

syslog is here.

 

http://pastebin.com/m2e072b6c

[abq-pete]

Jeller316,

 

Your speed issue is not with the Greenpower drives.  Both of my servers are running only with the WD10EACS and my parity checks are in the 45 MB/s (12 drive unit) to 65 MB/s (4 drive unit) range depending on which server I test (different motherboards).  WHat hardware are you using?

 

Erikatcuse,

 

I tried that mod when you first posted it but forgot to report that I measured no difference. 

 

Regards,  Peter

[SSD]

There is definitely something squirrley going on with the queue_depth in 4.4.2 vs 4.3.

 

Check out this post.

 

I'm back to running 4.3.3 for the time being.

 

[jeller316]

here is my setup

 

mobo Gigabyte GA-8I915GA pro 4 sata

2 Syba pcie sta cards

7 sata drives

parity device: pci-0000:00:1f.2-scsi-1:0:1:0 (sdh) ata-WDC_WD10EACS-00D6B1_WD-WCAU44222777

disk1 device: pci-0000:00:1f.2-scsi-0:0:0:0 (sde) ata-WDC_WD5000AAKS-00TMA0_WD-WCAPW2285667

disk2 device: pci-0000:02:00.0-scsi-0:0:0:0 (sdd) ata-ST3320620AS_9QF22LTR

disk3 device: pci-0000:01:00.0-scsi-0:0:0:0 (sda) ata-WDC_WD4000AAKS-00A7B0_WD-WMASY0752723

disk4 device: pci-0000:01:00.0-scsi-1:0:0:0 (sdb) ata-Maxtor_6V250F0_V506ESXG

disk5 device: pci-0000:00:1f.2-scsi-1:0:0:0 (sdg) ata-WDC_WD5000AACS-00ZUB0_WD-WCASU2123742

disk6 device: pci-0000:00:1f.2-scsi-0:0:1:0 (sdf) ata-WDC_WD10EACS-00D6B1_WD-WCAU44201025

 

I have tried everything that was suggested. I changed all queue_depth set to 1 parity speed average 1.5mbs. I could not figure out how to change the parity drive to make it a 31. Just to be sure I changed all cables and I moved the 2 wd green drives to the pcie card just to see if there would be any difference, none. I reverted back to 4.3.3 but still have the same speeds. I still set all drives to 1 no effect. I just don't know what to do? Send both dries back and get new ones it seems that it would be unlikely that both drives are bad I assume it is just something in my setup.

 

The only way I can get better speeds is to take both wd caviar green drives out of the array. I have my old 500gb parity drive here I put it back in and my speeds jump to 18-20mbs. Which is obviously way faster, of course not as fast as some post. How do you get 50-80 mbs? Better hardware?

 

[erikatcuse]

Comparing your syslog with mine the one thing I noticed is only two of your drive have "SATA link up 3.0 Gbps"  when I checked mine each one did.  This could be the problem but I'm not sure what you would need to do.

 

In your bios check to see if you have ahci mode or advance ide mode.  Also you might want to check and see if you can find a updated bios for your 2 pcie cards.  You could also check your syslog without your two WD drives attached and see if the "SATA link up 3.0 Gbps" appears more than twice.  I would also go into bios and disable anything you don't need.  Com ports, parallel ports, ide....

 

Also have you tried to disconnect 2 other drives and leave the 2 WD drives attached?  Another test you could do is if you don't have any data on the 2 WD drives is just leave those 2 connect and assign one as parity and the other as a data disk and do a parity check.  You could then post that syslog as well and see if there are any problems.

[SSD]

jeller316 -

 

I can feel your frustration.  Unfortunately we are not able to solve all problems nor even be able suggest the best next steps.  We're pretty good about issues that relate to SMART attributes, cabling, syslog problems, and unRAID settings.  If a system is working one day and not the next, we're pretty good at helping get it working again.  We're not as good with issues of incompatibility and general unexplained phenomina.  Realize that your problem does not seem to change with setting changes that have fixed or at least changed symptoms for other users having similar symptoms, nor with different versions of unRAID.  These two pont to something completely external to unRAID - either your BIOS or hardware.

 

I noticed in the syslog that your SATA drives appear to be in IDE emulation mode.  Have you tried AHCI mode?  (Apologies if you've already been down this road).

 

I did a quick search of the forums and could not find reference to others using your motherboard.  It doesn't mean you are having a motherboard compatibility issue, but a motherboard only used by one or a very few users could easily have some unknown compatiblity issues.  There was an issue a while back of 2 users that had issues adding more than 4 (I think) drives.  After that parity would not compute reliably.  Nothing we did fixed that problem - so we chocked it up to motherboard compatibility.  You may be having something similar going on, but I'd do a lot more trial-and-error testing before giving up (see next paragraph).  It seems unlikely that these drives would cause compatibility issues with your motherboard, but it could be.  Have you checked for a BIOS update?  Sometimes release notes will say give you a hint of a fix to a problem like this.  Other times you just need to try it and see.

 

If the AHCI suggestion doesn't help, I'd be going through the BIOS with a fine tooth comb disabling anything that I didn't need and experimenting (or at least Googling) options I didn't understand.  If that didn't help, I'd likely try hooking up those drives to my test unRAID server and see if the problem occurs there.  If so, the drives may be bad or just incompatible with Linux (I doubt that but could be).  If the drives behaved normally in my test setup, I know I have an issue related to my main system.  I'd put the two drives back in there, I would backup my "config" directory on the flash (you should really do this before you start) and disconnect all drives EXCEPT those 2.  Remove any external controllers.  Hook the drives directly to the motherboard (no trays, docks, external enclosures, etc.) with known good cables.  If the problem persists, I'd be looking for a motherboard BIOS update.  Lacking one, I'd be looking for anther motherboard - or know that I need to avoid certain drives with that motherboard and unRAID.

 

Hope this helps.

[abq-pete]

Jeller316,

 

I could not find your motherboard at Gigabytes website.  The closest one seems to be the GA-8I915G Pro running Intel's ICH6 chipset.  The latest bios is from 2005 and makes no mention of updates to drive controllers.

 

You mentioned that you replaced your motherboard.  Did you replace it with the same model/revision, or with something completely different?  If it was the same model/revision, it is possible that the board just isn't quite as compatible as others.

 

Regards,  Peter

[jeller316]

Yes I believe it is my mobo. I had a spare machine sitting here so I put the free unraid on it and added the 2 wd caviar green drives to it to see what speeds I would get. 45mbs! So I guess my next step is to buy a new mobo combo, any suggestions? I have 2 syba pcie cards I need to untilize. The only thing I need to have is 4 sata on board at least.

[prostuff1]

I would say check out the Hardware Compatibility page and just do some search on here and newegg to get some reviews.

[jeller316]

Ok so I started doing some testing. Long story short, after I found that my 2 drives I thought were in question worked fine in a test unraid I hooked everything back up in my server and presto I had 55mbs parity check speeds. I bought 4 "bay coolers" item#330286710321 from ebay each has 3 small fans in it so I could use my dvd bays for harddrives when I hook anyone of these up to power boom speed drops. When I had 53mbs I plugged just one cooler in and speed dropped to 10mbs. I tried the others one at a time and they all drop the speed at least 30mbs.

 

So my question iis does anyone know why this would happen?

 

I put a coolmaster 600watt ps in this thought it would be enough. Maybe these cooler are just cheap and pull to much power?

 

Ant suggestions would be great, I will have to replace these with something so the drives don't fry.

 

FYI here is alink to the bay cooler I bought. 

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330286710321&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2Fsearch%2Fsearch.dll%3Ffrom%3DR40%26_trksid%3Dm37%26satitle%3D330286710321%26category0%3D%26fvi%3D1

[prostuff1]

Ok so I started doing some testing. Long story short, after I found that my 2 drives I thought were in question worked fine in a test unraid I hooked everything back up in my server and presto I had 55mbs parity check speeds. I bought 4 "bay coolers" item#330286710321 from ebay each has 3 small fans in it so I could use my dvd bays for harddrives when I hook anyone of these up to power boom speed drops. When I had 53mbs I plugged just one cooler in and speed dropped to 10mbs. I tried the others one at a time and they all drop the speed at least 30mbs.

 

So my question iis does anyone know why this would happen?

 

I put a coolmaster 600watt ps in this thought it would be enough. Maybe these cooler are just cheap and pull to much power?

 

Ant suggestions would be great, I will have to replace these with something so the drives don't fry.

 

FYI here is alink to the bay cooler I bought. 

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330286710321&ru=http%3A%2F%2Fsearch.ebay.com%3A80%2Fsearch%2Fsearch.dll%3Ffrom%3DR40%26_trksid%3Dm37%26satitle%3D330286710321%26category0%3D%26fvi%3D1

 

I have no idea why those bays would be doing that.  The power supply should be enough to power the bays. I would check out something like this and see if that works any better.  It should def. be more quite as it uses a 120mm fan and not three small ones.

[SSD]

Great detective work!

 

Seems odd these little guys would have caused a problem.  Do the SATA and PSU cables still plug directly into the drive?  (Some docks and trays have a built in plug that connects to the drive drive and the cables plug into the back of the dock.  These don't appear to be that way.  This is a good thing for good connections IMO.). Are you using different splitters when these are being used vs not?

 

I would try using them but not plugging in the fans and see if the speed goes back up, to try to narrow down more specifically what it is about these things that is causing problems.  I don't think it is that they are pulling too much power.  I'd be more suspecting that they are somehow giving off interference.  Maybe the magnets in the fans are too big and causing problems.  (As I think about it, this is seeming a likely candidate).

 

It could also be that your SATA cables are somehow getting too close to your PSU or other source of electrical interference inside the case.  Maybe when you pulled the coolers you ran the SATA cables differently?

 

With a bit more detective work I'm sure you'll figure it out.

 

BTW, I have something similar to these in my case made by Antec I think.  The three fans don't move much air at all.  I yanked the fans and just use it as an attractive air intake on the front of the case (looks much better than just pulling off the cover plate ).  120mm fans behind it pull air through the slits into the case. 

 

[abq-pete]

I cannot tell but are you plugging the fans directly into the motherboard itself or into spare molex connections from the power supply?  If the former, you may be drawing too much power from the motherboard and maybe causing the cpu or chipset to starve a bit.  Another thing you can try is moving another computer near your existing one and running the new fans from that one...

 

Regards,  Peter

[lionelhutz]

If you are up to doing some mods, you could gut the fans from those units. Then, block off any air intake paths in your case besides these docks. Put a couple of big high flow 120mm exaust fans in your case and use them to suck air across the drives. Since you blocked off all other air intake paths the air has to flow across your drives. Heck, I doubt you even have to take the fans out of those trays.

 

Peter

 

[SSD]

BTW, I have something similar to these in my case made by Antec I think.  The three fans don't move much air at all.  I yanked the fans and just use it as an attractive air intake on the front of the case (looks much better than just pulling off the cover plate ).  120mm fans behind it pull air through the slits into the case. 

 

Great minds think alike ...

[jeller316]

Wanted to update this. After I found out the fans were the problem I continued some testing. First I plugged the fans into a second computer for power to make sure there were no inadequate power problems. But the parity check was around 2-3mbs so power consumption was not an issue. I took the drive bays out and moved each hd away from the 3 fans as far as I could about 1 1/2 inches the parity speed went from 50mbs to about 10mbs notice this is not the 2mbs I was getting. So what I would take from this is that the fans are producing some sort of interference probably from the magnets? The farther away the fans are from any of my drives the faster the parity check is.

I had some old fans from a different brand of harddrive cooler and I put them right in front of these drives and there is no slow down in speeds.

 

I ordered a 4 in 3 bay cooler cage from newegg should have no problems now.

 

Thanks everyone for the help and suggestions.

[fitbrit]

Wanted to update this. After I found out the fans were the problem I continued some testing. First I plugged the fans into a second computer for power to make sure there were no inadequate power problems. But the parity check was around 2-3mbs so power consumption was not an issue. I took the drive bays out and moved each hd away from the 3 fans as far as I could about 1 1/2 inches the parity speed went from 50mbs to about 10mbs notice this is not the 2mbs I was getting. So what I would take from this is that the fans are producing some sort of interference probably from the magnets? The farther away the fans are from any of my drives the faster the parity check is.

I had some old fans from a different brand of harddrive cooler and I put them right in front of these drives and there is no slow down in speeds.

 

I ordered a 4 in 3 bay cooler cage from newegg should have no problems now.

 

Thanks everyone for the help and suggestions.

 

Wow, good work... and scary conclusion!