Slow data rebuild / par check (10-15 MB/sec)


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Hey guys

 

I always had slow data rebuild and parity checks and just thought it was normal. Now I had a drive redball and according to the wiki it's probably a bad cable, smart checks are OK. I replaced the cable and now i'm doing a rebuild on the drive with 2477 minutes left @12MB/S.

 

I have 9 data drives (mostly 2tb wd green), a cache drive and a 2tb parity drive.

On the motherboard (ms-7125) i have 8 sata connections + a SIL sata card

3gb ddr memory

Powersuppy - Antec EA 500. 500w - +3.3V@24A, +5V@24A, +12V1@17A, +12V2@17A, [email protected], [email protected] - 5v 3,3v max load 130w +12v1 +12v2 max load 408w.

 

Here is my syslog http://pastebin.com/hDK3Tybf and hopefully you guys can give me advice on what to upgrade/tweak :)

 

Thanks

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You probably need to upgrade the power supply.  (Actually, with that many disks, way past the time to upgrade)

 

On multi-rail supplies it is  VERY common for all the disk drive connectors to share the same rail (and sometimes sharing it also with the motherboard connector)

You basically have a 17 Amp supply and 11 disks, each drawing about 2 Amps when spinning up.  Add that to power the case fans (and possibly the motherboard) draw and you are probably trying to draw 24 Amps or more from the poor power supply.

 

It is why a single 12 Volt rail supply is recommended foran unRAID array of any size.  Basically, 1/2 of your power supply capacity is not accessible.  You will run into all kinds of weird errors.  You probably should have a supply with single 12 Volt rail of 35 Amps or more.

 

Joe L.

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    You are using an old motherboard. Motherboards 8-10 years ago were not build as the ones now and when they age there are going to be all sorts of gremlins in your system. Never mind that in the "Hardware Compatibility" list nForce 4 based motherboards are not recommended to be used. - http://lime-technology.com/wiki/index.php/Hardware_Compatibility#Motherboard_SATA_controllers

If you can live with all that - no problems - just realize that you are running with higher risks than the majority of the other users

 

Second - as the system is old you may have forgotten that you do have two SIL cards inside and not one as you said.

 

Oct 28 17:55:01 SERVER kernel: sata_sil 0000:01:06.0: version 2.4

Oct 28 17:55:01 SERVER kernel: sata_sil 0000:01:06.0: Applying R_ERR on DMA activate FIS errata fix

Oct 28 17:55:01 SERVER kernel: scsi1 : sata_sil

Oct 28 17:55:01 SERVER kernel: scsi5 : sata_sil

Oct 28 17:55:01 SERVER kernel: scsi6 : sata_sil

Oct 28 17:55:01 SERVER kernel: scsi7 : sata_sil

Oct 28 17:55:01 SERVER kernel: sata_sil 0000:01:0d.0: Applying R_ERR on DMA activate FIS errata fix

Oct 28 17:55:01 SERVER kernel: scsi8 : sata_sil

Oct 28 17:55:01 SERVER kernel: scsi9 : sata_sil

Oct 28 17:55:01 SERVER kernel: scsi10 : sata_sil

Oct 28 17:55:01 SERVER kernel: scsi11 : sata_sil

 

If these are the slow PCI 4-ports devices you are saturating the PCI bus resulting in always "slow" parity checks and rebuilds - no other ways around that. But this is only when you perform these two operations - in regular use you probably wont feel the slowness - just keep the parity disk on the motherboards SATA ports

 

Only way to speed up the system parity checks and rebuilds only is by purchasing a relatively low cost 8-ports HBA - assuming it will work in the motherboards PCIe-x16 slot.

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I have gotten a better psu so I will sleep better at night and the disk rebuild went fine.

 

The motherboard + cpu + memory combo are doing fine and the mb has a x4 PCI Express slot.

 

Should I order AOC-SASLP-MV8 or am I mistaken that they are still among the best choices?

 

Found out that it only works as x2

 

Back to the drawing board

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Sorry guys, but one more question:

 

I decided to update:

ASRock B75 Pro3

Core i3-2120 SB (3,3ghz)

8gb ddr3 memory

 

I'm getting a par check of 30-40 MB/s on the slow pci sata card (3 drives) so that is ok for the moment.. but I want to get a proper card with 8 connections.

 

I will be ordering online so is the  SASLP-MV8 still the best bet or should I go for the LSI ones?

 

Thanks for your input.

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