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45MB/s to 10MB/s after adding Parity Drive

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Hi, this is a new server build (4.5.6) with 4 SATA drives on the motherboard. I initially set it up with 3 unprotected drives (no parity drive) and copied over all my DVD/Blurays. I got transfer rates of 45-50MB/s over 1GB Ethernet.

 

I just added a new 2TB WD drive and let it do it's parity thing. All green. Went to transfer a new movie today, and I'm now getting transfer rate of 8-10MB/s... ouch! Should there be this big of a performance hit? Or did I do something wrong?

 

If this is normal, is my only option to add a cache drive? Or are there other ways to get the data over quicker?

Most people get something like 25-35MB/s with parity

On the other hand they get much more without parity (I have not used Unraid without parity for a long time, so correct me if I am wrong. Is 45Mb/s normal when no parity is installed?)

 

So, your problem might not be the parity drive but slow transfer speeds in general.

Hi, this is a new server build (4.5.6) with 4 SATA drives on the motherboard. I initially set it up with 3 unprotected drives (no parity drive) and copied over all my DVD/Blurays. I got transfer rates of 45-50MB/s over 1GB Ethernet.

 

I just added a new 2TB WD drive and let it do it's parity thing. All green. Went to transfer a new movie today, and I'm now getting transfer rate of 8-10MB/s... ouch! Should there be this big of a performance hit? Or did I do something wrong?

 

If this is normal, is my only option to add a cache drive? Or are there other ways to get the data over quicker?

 

Have you enabled the SATA AHCI mode on the BIOS? AHCI mode is known to provide extra performance on disk access.

 

Other option is deactivate NCQ on the Setings menu of the webui.

  • Author

I have NCQ Force Disable set to Yes. I'll check the AHCI setting tonight.

 

From the reading I've done, I thought 50MB/s was pretty good without Parity, so with that in mind thought everything was working well, drives, network, etc. That's why I was surprised to see it drop so much after adding the parity drive, I knew I would take a hit in performance... just not that much of one.

I have NCQ Force Disable set to Yes. I'll check the AHCI setting tonight.

 

From the reading I've done, I thought 50MB/s was pretty good without Parity, so with that in mind thought everything was working well, drives, network, etc. That's why I was surprised to see it drop so much after adding the parity drive, I knew I would take a hit in performance... just not that much of one.

 

You are getting a taste of what unRAID performance was like before the latest round of performance improvements.  At that time 10-12 MB/sec was pretty normal.  A few people got 14, and that was considered exceptional! 

 

If you are getting that slow performance with a current version there is something wrong.  There could be a gazillion reasons why - but the forum would only be guessing unless you provide a syslog.  My guess is that it is full of errors and trace back to a bad disk or loose connection.

 

Follow the troubleshooting link in my sig for instructions on getting and posting a syslog.

 

Until you get this worked out, I would not trust any data you have added to the unRAID server.

  • Author

Attached is my syslog. Thanks everyone for taking the time to work through this with me... I appreciate the help!

syslog.11.02.10.txt

What do you get when you type ethtool eth0 ?

What kind of cables are you connecting from your unraid to the router/switch and from your pc to the router/switch?

This EARS parity disk has disk name as hdc. a SATA disk should not have name starting with h but s, it should be sdc.

and system had handshake with this disk in PIO4 mode. Are you using SATA-2-IDE converter?

 

 

Oct 30 10:58:16 Tower kernel: hdc: WDC WD20EARS-00J2GB0, ATA DISK drive

Oct 30 10:58:16 Tower kernel: hdd: WDC WD20EADS-00S2B0, ATA DISK drive

Oct 30 10:58:16 Tower kernel: hdc: host max PIO4 wanted PIO255(auto-tune) selected PIO4

Oct 30 10:58:16 Tower kernel: hdc: UDMA/100 mode selected

Oct 30 10:58:16 Tower kernel: hdd: host max PIO4 wanted PIO255(auto-tune) selected PIO4

Oct 30 10:58:16 Tower kernel: hdd: UDMA/100 mode selected

 

 

Oct 30 10:58:18 Tower kernel: md: unRAID driver 0.95.4 installed

Oct 30 10:58:18 Tower kernel: md: import disk0: [22,0] (hdc) WDC WD20EARS-00J2GB0 WD-WCAYY0204387 offset: 63 size: 1953514552

Oct 30 10:58:18 Tower kernel: md: import disk1: [8,16] (sdb) WDC WD20EADS-00S WD-WCAVY3791754 offset: 63 size: 1953514552

Oct 30 10:58:18 Tower kernel: md: import disk2: [22,64] (hdd) WDC WD20EADS-00S2B0 WD-WCAVY3838951 offset: 63 size: 1953514552

Oct 30 10:58:18 Tower kernel: md: import disk3: [8,0] (sda) WDC WD10EACS-00D WD-WCAU43969778 offset: 63 size: 976762552

 

 

This EARS parity disk has disk name as hdc. a SATA disk should not have name starting with h but s, it should be sdc.

and system had handshake with this disk in PIO4 mode. Are you using SATA-2-IDE converter?

 

 

Oct 30 10:58:16 Tower kernel: hdc: WDC WD20EARS-00J2GB0, ATA DISK drive

Oct 30 10:58:16 Tower kernel: hdd: WDC WD20EADS-00S2B0, ATA DISK drive

Oct 30 10:58:16 Tower kernel: hdc: host max PIO4 wanted PIO255(auto-tune) selected PIO4

Oct 30 10:58:16 Tower kernel: hdc: UDMA/100 mode selected

Oct 30 10:58:16 Tower kernel: hdd: host max PIO4 wanted PIO255(auto-tune) selected PIO4

Oct 30 10:58:16 Tower kernel: hdd: UDMA/100 mode selected

 

 

Oct 30 10:58:18 Tower kernel: md: unRAID driver 0.95.4 installed

Oct 30 10:58:18 Tower kernel: md: import disk0: [22,0] (hdc) WDC WD20EARS-00J2GB0 WD-WCAYY0204387 offset: 63 size: 1953514552

Oct 30 10:58:18 Tower kernel: md: import disk1: [8,16] (sdb) WDC WD20EADS-00S WD-WCAVY3791754 offset: 63 size: 1953514552

Oct 30 10:58:18 Tower kernel: md: import disk2: [22,64] (hdd) WDC WD20EADS-00S2B0 WD-WCAVY3838951 offset: 63 size: 1953514552

Oct 30 10:58:18 Tower kernel: md: import disk3: [8,0] (sda) WDC WD10EACS-00D WD-WCAU43969778 offset: 63 size: 976762552

 

 

I did not catch that.... good eyes.

 

It could easily be the BIOS is set to Legacy IDE Emulation mode for those disk controller ports instead of AHCI.  Many BIOS have that as the default, otherwise older Microsoft OS would not be able to boot from the SATA drives, since those older OS had no SATA drivers.

 

Joe L.

I did not catch that.... good eyes.

 

It could easily be the BIOS is set to Legacy IDE Emulation mode for those disk controller ports instead of AHCI.  Many BIOS have that as the default, otherwise older Microsoft OS would not be able to boot from the SATA drives, since those older OS had no SATA drivers.

 

Joe L.

 

There are ahci messages in syslog so i will assume AHCI has been enabled.

 

Oct 30 10:58:16 Tower kernel: scsi1 : ahci

Oct 30 10:58:16 Tower kernel: scsi2 : ahci

Oct 30 10:58:16 Tower kernel: scsi3 : ahci

Oct 30 10:58:16 Tower kernel: scsi4 : ahci

 

When i was using IDE mode in my MSI MB, all SATA disks still have names starting with s not h.

 

 

These two disks were probed through a controller that is from a AMD MB. Maybe AMD MB has different implementation. AMD SB400 south bridge chip?

 

Oct 30 10:58:16 Tower kernel: CPU0: AMD Sempron 140 Processor stepping 02

 

Oct 30 10:58:16 Tower kernel: atiixp 0000:00:14.1: IDE controller (0x1002:0x439c rev 0x00)

Oct 30 10:58:16 Tower kernel: ATIIXP_IDE 0000:00:14.1: PCI INT A -> GSI 16 (level, low) -> IRQ 16

Oct 30 10:58:16 Tower kernel: atiixp 0000:00:14.1: not 100%% native mode: will probe irqs later

Oct 30 10:58:16 Tower kernel:    ide0: BM-DMA at 0xff00-0xff07

Oct 30 10:58:16 Tower kernel:    ide1: BM-DMA at 0xff08-0xff0f

Oct 30 10:58:16 Tower kernel: Probing IDE interface ide0...

Oct 30 10:58:16 Tower kernel: Probing IDE interface ide1...

Oct 30 10:58:16 Tower kernel: hdc: WDC WD20EARS-00J2GB0, ATA DISK drive

Oct 30 10:58:16 Tower kernel: hdd: WDC WD20EADS-00S2B0, ATA DISK drive

Oct 30 10:58:16 Tower kernel: hdc: host max PIO4 wanted PIO255(auto-tune) selected PIO4

Oct 30 10:58:16 Tower kernel: hdc: UDMA/100 mode selected

Oct 30 10:58:16 Tower kernel: hdd: host max PIO4 wanted PIO255(auto-tune) selected PIO4

Oct 30 10:58:16 Tower kernel: hdd: UDMA/100 mode selected

Oct 30 10:58:16 Tower kernel: ide0 at 0x1f0-0x1f7,0x3f6 on irq 14

Oct 30 10:58:16 Tower kernel: ide1 at 0x170-0x177,0x376 on irq 15

Oct 30 10:58:16 Tower kernel: ide-gd driver 1.18

Oct 30 10:58:16 Tower kernel: hdc: max request size: 512KiB

Oct 30 10:58:16 Tower kernel: hdc: 3907029168 sectors (2000398 MB), CHS=65535/255/63

Oct 30 10:58:16 Tower kernel: hdc: cache flushes supported

Oct 30 10:58:16 Tower kernel:  hdc: hdc1

Oct 30 10:58:16 Tower kernel: hdd: max request size: 512KiB

Oct 30 10:58:16 Tower kernel: hdd: 3907029168 sectors (2000398 MB) w/32767KiB Cache, CHS=65535/255/63

Oct 30 10:58:16 Tower kernel: hdd: cache flushes supported

Oct 30 10:58:16 Tower kernel:  hdd: hdd1

 

I did not catch that.... good eyes.

 

It could easily be the BIOS is set to Legacy IDE Emulation mode for those disk controller ports instead of AHCI.  Many BIOS have that as the default, otherwise older Microsoft OS would not be able to boot from the SATA drives, since those older OS had no SATA drivers.

 

Joe L.

 

There are ahci messages in syslog so i will assume AHCI has been enabled.

I've seen BIOS where there were two SATA controllers on the MB, and they each had their own setting for Legacy Mode vs. AHCI.
  • Author

Ok well this is all pretty interesting stuff :)

 

Here is where I'm at... it's an Asus M4A78L-M motherboard by the way.

 

1) I removed the Parity drive from the configuration so I could start from scratch (also because you caught me Joe L., I did not install the jumper because I didn't have one initially. I've got it on there now though)

 

2) Went into bios and it does have 2 controllers on-board, both were set to IDE. I set the first one to AHCI and it automatically sets the second one that way. Unfortunately after I did that 2 of my drives disappeared. The only thing different about the drives that disappeared was they were on the second controller, switched them over to the first controller and they re-appeared. Weird but I don't feel like troubleshooting that now, will wait till it's time to add the 5th drive.

 

3) So back into unRaid, had to tell it were the drives were again and everything is good. Left it with no Parity drive for now. Did a quick transfer test and BOOM, 68MB/s. Didn't stay that way for the whole time but ended up with a sustained 59-60 which is better than before.

 

4) Just added the Parity Drive back in and it's doing a sync now. Says it's going to take 9 hours! This weekend when I first put it in it took 24 hours.

 

So I THINK things are looking up. I'll try the transfer again tomorrow after the sync and let you know how it goes.

 

Thanks again everyone for all your guidance! Also is attached a new syslog.

syslog.11.02.10-2.txt

Looks like this MB has 4+2 SATA ports, 2 of them are separated from the rest of 4. Now you have 6 ports running with AHCI and all SATA disks are detected correctly.

 

Nov  2 17:32:22 Tower kernel: scsi1 : ahci

Nov  2 17:32:22 Tower kernel: scsi2 : ahci

Nov  2 17:32:22 Tower kernel: scsi3 : ahci

Nov  2 17:32:22 Tower kernel: scsi4 : ahci

Nov  2 17:32:22 Tower kernel: scsi5 : ahci

Nov  2 17:32:22 Tower kernel: scsi6 : ahci

 

Nov  2 17:32:23 Tower emhttp: Device inventory:

Nov  2 17:32:23 Tower emhttp: pci-0000:00:11.0-scsi-0:0:0:0 host1 (sda) WDC_WD20EARS-00J2GB0_WD-WCAYY0204387

Nov  2 17:32:23 Tower emhttp: pci-0000:00:11.0-scsi-1:0:0:0 host2 (sdb) WDC_WD10EACS-00D6B1_WD-WCAU43969778

Nov  2 17:32:23 Tower emhttp: pci-0000:00:11.0-scsi-2:0:0:0 host3 (sdc) WDC_WD20EADS-00S2B0_WD-WCAVY3791754

Nov  2 17:32:23 Tower emhttp: pci-0000:00:11.0-scsi-3:0:0:0 host4 (sdd) WDC_WD20EADS-00S2B0_WD-WCAVY3838951

 

Nov  2 17:32:23 Tower kernel: md: disk0 removed

Nov  2 17:32:23 Tower kernel: md: import disk1: [8,32] (sdc) WDC WD20EADS-00S WD-WCAVY3791754 offset: 63 size: 1953514552

Nov  2 17:32:23 Tower kernel: md: import disk2: [8,48] (sdd) WDC WD20EADS-00S WD-WCAVY3838951 offset: 63 size: 1953514552

Nov  2 17:32:23 Tower kernel: md: import disk3: [8,16] (sdb) WDC WD10EACS-00D WD-WCAU43969778 offset: 63 size: 976762552

 

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