I recently set up and purchased an unraid license for my first NAS. I'm running the latest beta on some WD reds. I have a gigabit network and have verified all the tech is working. I can write data to my Unraid box at roughly 100 MBps with a cache disk or 30-40 without. I've recently done some testing to see what the read speeds are and I'm only getting 6-7 MBps on a good day, usually less.

 

Attached is a syslog. I can provide more information as needed. I'm not running any plugins save the apcupsd plugin.

 

My specs are as follows.

 

PCI Devices

00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 12)
00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 12)
00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06)
00:16.2 IDE interface: Intel Corporation 5 Series/3400 Series Chipset PT IDER Controller (rev 06)
00:16.3 Serial controller: Intel Corporation 5 Series/3400 Series Chipset KT Controller (rev 06)
00:19.0 Ethernet controller: Intel Corporation 82578DM Gigabit Network Connection (rev 06)
00:1a.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06)
00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 06)
00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 06)
00:1d.0 USB controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a6)
00:1f.0 ISA bridge: Intel Corporation 5 Series Chipset LPC Interface Controller (rev 06)
00:1f.2 IDE interface: Intel Corporation 5 Series/3400 Series Chipset 4 port SATA IDE Controller (rev 06)
00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 06)
00:1f.5 IDE interface: Intel Corporation 5 Series/3400 Series Chipset 2 port SATA IDE Controller (rev 06)
01:00.0 IDE interface: JMicron Technology Corp. JMB368 IDE controller
3f:00.0 Host bridge: Intel Corporation Core Processor QuickPath Architecture Generic Non-core Registers (rev 02)
3f:00.1 Host bridge: Intel Corporation Core Processor QuickPath Architecture System Address Decoder (rev 02)
3f:02.0 Host bridge: Intel Corporation Core Processor QPI Link 0 (rev 02)
3f:02.1 Host bridge: Intel Corporation Core Processor QPI Physical 0 (rev 02)
3f:02.2 Host bridge: Intel Corporation Core Processor Reserved (rev 02)
3f:02.3 Host bridge: Intel Corporation Core Processor Reserved (rev 02)
USB Devices

Bus 002 Device 003: ID 051d:0002 American Power Conversion Uninterruptible Power Supply
Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 05dc:a838 Lexar Media, Inc. 
Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
SCSI Devices

[2:0:1:0]    disk    ATA      WDC WD20EFRX-68A 0A80  /dev/sda 
[3:0:1:0]    disk    ATA      WDC WD20EFRX-68A 0A80  /dev/sdb 
[4:0:0:0]    disk    ATA      WDC WD20EFRX-68A 0A80  /dev/sdc 
[5:0:0:0]    disk    ATA      WDC WD20EFRX-68A 0A80  /dev/sdd 
[6:0:0:0]    disk    Lexar    USB Flash Drive  1100  /dev/sde 

syslog.txt

I have taken additional steps to troubleshoot this. I have a laptop and a desktop wired into the same switch as the Unraid box. I have copied very large files between my desktop and laptop with no issue. Write speed was roughly 100 MBps which is what I would expect.

 

I've cycled all of the network cables in use and they all work fine.

 

I have 2 gigs of RAM in the unraid box and I've noticed when reading from it the RAM fills up past 85-90 percent. I don't know how Linux utilizes RAM well enough to know of this is an issue.

 

Where else should I look? I have no plugins installed save for apcupsd and all of my disks have passed SMART tests. It would seem the bottlenecking is occurring on the unraid box but I don't know where and I don't know why.

Try plugging the laptop directly into the unraid box and take the switch out of the equation. Try reading from all the different drives in the unraid box, including the flash drive.

 

For the ram issue, read here.

 

http://www.linuxatemyram.com/

Same results. Directly connected to the box does not help. Copying directly from one drive to another via Windows Explorer doesn't increase anything either on the clients. Flash is also the same. Are there Windows settings that could be affecting this?

 

To my mind the confusing part of this is how writing to the box is still nice and zippy at 60 MBps, or 100 with cache but reading is slow.

So I swapped mobos with another I had lying around that also had a gigabit NIC and now I can do both reads and writes at a gigabit speed. Not sure what happened with the other board but whatever, this one works too.