Hi folks,

 

My current setup is that I have a 4-bay NAS (QNAP TR-004) connected to my ASUS - Zenbook 14X 14.5" laptop over USB 3.2 Gen 1. The drives in the DAS are Seagate BarraCuda 8TB Internal Hard Drive HDD – 3.5 Inch (ST8000DMZ04/004). 

 

There is a bunch of stuff wrong with this setup. The drives are not great drives (something about SMR vs CMR), connecting via USB is a bad idea, the laptop is not a real server, etc. etc.

 

However, I still do not understand why the speeds I am getting are below 20 MB/s.

 

The drives support 6 Gbps but the max sustained transfer rate is 190 MB/s, USB 3.2 Gen 1 supports supports 5 Gbps, my laptop supports USB 3.2 Gen 2 with speeds of 10 Gbps. The limiting factor here should be the drives at 190 MB/s; cut that in half and I'd still expect 100 MB/s. What am I missing? I guess another link in the chain is my WiFi. This is all happening over LAN, but the WiFi is still involved here right? That's able to do at least 60 MB/s. 

 

The computer is this (https://www.asus.com/us/laptops/for-home/zenbook/zenbook-14x-oled-q420/techspec/).

 

The DAS is this (https://www.qnap.com/en-us/product/tr-004)

 

The drives are here https://www.seagate.com/www-content/datasheets/pdfs/3-5-barracudaDS1900-11-1806US-en_US.pdf, though I can't find my exact model. 

First, the best replies come when you post diagnostics.

 

File transfer speed curiosities to test:

Disk > Disk on Qnap

Qnap > Laptop

Qnap > Other device(s) - Believe this is the 20MBs observed.

 

This will help paint the picture better.

And what are you transferring?  Small files have much more file overhead than large files.  (I have seen transfer speed drop into the single digit MB/s speed when the files sizes are in the 60KB range while reaching 100+ MB/s when transferring 20GB .MKV files in the same transfer!)

 

EDIT: Remember that the 190 MB/s is when the disk is empty.  It will slow as the disk become full!

Edited September 4, 20241 yr by Frank1940

16 hours ago, Veah said:

First, the best replies come when you post diagnostics.

 

File transfer speed curiosities to test:

Disk > Disk on Qnap

Qnap > Laptop

Qnap > Other device(s) - Believe this is the 20MBs observed.

 

This will help paint the picture better.

 

I am wondering when to capture the diagnostic file. Should I do the tests you've outlined and, after each test, download the diagnostic file? 

15 hours ago, Frank1940 said:

And what are you transferring?  Small files have much more file overhead than large files.  (I have seen transfer speed drop into the single digit MB/s speed when the files sizes are in the 60KB range while reaching 100+ MB/s when transferring 20GB .MKV files in the same transfer!)

 

EDIT: Remember that the 190 MB/s is when the disk is empty.  It will slow as the disk become full!

I am transferring 1 2GB file, as this mirrors my usage of the system much more closely than many small files. 

For what it is worth, I ssh'd into unraid and ran `dd if=/dev/zero of=/mnt/disk2/archive/testfile bs=1G count=5` and got 28MB/s. This rules out a problem with SMB, WiFi, etc. 

 

I ran `lsusb -v` and confirmed that that the device was recognized as USB 3.1:

 

Bus 004 Device 002: ID 1c04:0013 QNAP System Inc. TR-004
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               3.10

 

 

`hdparm -tT /dev/disk/by-label/disk1` gave me:

 

./disk1:
 Timing cached reads:   39324 MB in  2.00 seconds = 19694.33 MB/sec
 Timing buffered disk reads: 620 MB in  3.00 seconds = 206.50 MB/sec

 

And `smartctl -a ./disk1` is a bit useless as the drives don't have any SMART capabilities:

 

root@unraid:/dev/disk/by-label# smartctl -a ./disk1
smartctl 7.4 2023-08-01 r5530 [x86_64-linux-6.1.79-Unraid] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Vendor:               QNAP
Product:              TR-004 DISK01
Revision:             6111
Compliance:           SPC-4
User Capacity:        8,001,563,222,016 bytes [8.00 TB]
Logical block size:   512 bytes
Physical block size:  4096 bytes
LU is fully provisioned
Logical Unit id:      0x3051323433423030
Serial number:        5132343342303035
Device type:          disk
Local Time is:        Wed Sep  4 23:51:35 2024 CDT
SMART support is:     Unavailable - device lacks SMART capability.

=== START OF READ SMART DATA SECTION ===
Current Drive Temperature:     0 C
Drive Trip Temperature:        0 C

Error Counter logging not supported

No Self-tests have been logged

 

On 9/4/2024 at 12:36 PM, stevenxl said:

The drives in the DAS are Seagate BarraCuda 8TB Internal Hard Drive HDD – 3.5 Inch (ST8000DMZ04/004). 

It could due to it is SMR disk.

 

6 hours ago, stevenxl said:

`dd if=/dev/zero of=/mnt/disk2/archive/testfile bs=1G count=5` and got 28MB/s.

 

6 hours ago, stevenxl said:

`hdparm -tT /dev/disk/by-label/disk1` gave me:

You need do same hdparm test on disk2.

Edited September 5, 20241 yr by Vr2Io

2 hours ago, Vr2Io said:

It could due to it is SMR disk.

 

 

You need do same hdparm test on disk2.

 

I thought that SMR only mattered in a RAID configuration. I don't have RAID enabled, thanks to the way that unRaid OS does the parity stuff.

 

Here are the results on running hdparm on disk2 and 3:

 

./disk2:
 Timing cached reads:   39360 MB in  2.00 seconds = 19712.98 MB/sec
 Timing buffered disk reads: 466 MB in  3.00 seconds = 155.08 MB/sec

./disk3:
 Timing cached reads:   39396 MB in  2.00 seconds = 19729.99 MB/sec
 Timing buffered disk reads: 594 MB in  3.00 seconds = 197.75 MB/sec

 

SMR could have slow WRITE problem no matter it RAID or not.

 

Your can perform some READ test by dd to /dev/null to confirm.

 

For hdparm result, it indicate no problem on interface ( USB ).

Edited September 5, 20241 yr by Vr2Io

8 minutes ago, stevenxl said:

I thought that SMR only mattered in a RAID configuration

It will matter any time you write a lot of data to a drive as performance plummets once its cache has filled up.

5 hours ago, Vr2Io said:

SMR could have slow WRITE problem no matter it RAID or not.

 

Your can perform some READ test by dd to /dev/null to confirm.

 

For hdparm result, it indicate no problem on interface ( USB ).

 

Thanks. At this point I think this is just the performance of these drives. I cheaped out on the whole setup thinking it would be enough. I think they are frankly, but the drives are crap.

 

Not to high-jack my own thread, but can you recommend one or two product lines for HDDs in the 8TB range that will give me better speeds than what I am seeing.  

The USB3 spec is great on paper.  The biggest problem is that the USB hardware/software when measured for quality/reliability seems to range from 1 to 5 on a zero-to-five scale with the mean being about 2.5.   And no one seems to have a clue as to how to improve things.  A contributing factor to this state of affairs is that it always being prompted as the cheapest solution.  That is why most of us regular Unraid support people tend to discourage folks from using it except for a occasional short term solution. 

3 hours ago, Frank1940 said:

The USB3 spec is great on paper.  The biggest problem is that the USB hardware/software when measured for quality/reliability seems to range from 1 to 5 on a zero-to-five scale with the mean being about 2.5.   And no one seems to have a clue as to how to improve things.  A contributing factor to this state of affairs is that it always being prompted as the cheapest solution.  That is why most of us regular Unraid support people tend to discourage folks from using it except for a occasional short term solution. 

what kind of setup would make sense? I hear folks use NAS but doesn’t that come with its own operating system? Do I need some kind of computer setup that exposes SATA ports directly? I’m just not sure how to attach storage as directly as possible to the computer, or in the correct way. 

Most people just use a normal desktop type computer, size depending on how many disk drives you anticipate. Disk cooling is a critical consideration.

 

A normal 4U rackmount server is also popular for very powerful builds.

5 hours ago, stevenxl said:

 

Thanks. At this point I think this is just the performance of these drives. I cheaped out on the whole setup thinking it would be enough. I think they are frankly, but the drives are crap.

 

Not to high-jack my own thread, but can you recommend one or two product lines for HDDs in the 8TB range that will give me better speeds than what I am seeing.  

I have build in different form factor and different hardware, I also previously use a 8 bay QNAP + 5bay USB enclosure to be a 13bay system, but currently was a 3U+2U rack 28bay system ( hba + expander ), more performance and robust.

 

Best avoid SMR disk, those usually little bit cheaper, but we also understand no choice for small size disk.

Edited September 6, 20241 yr by Vr2Io

1 hour ago, stevenxl said:

what kind of setup would make sense? I hear folks use NAS but doesn’t that come with its own operating system? Do I need some kind of computer setup that exposes SATA ports directly? I’m just not sure how to attach storage as directly as possible to the computer, or in the correct way. 

 

For example of what some folks use, turn on the signatures in the Forum posts as many of us list what we are using for our Unraid servers.  To display the signatures, click on your screen at the very top right of any forum page.  From the dropdown menu, pick "Account Settings".  Then look for "Signature" in the left hand block and click on it. Then toggle this switch:

 

Actually, the hardest thing to find these days is cases with enough 3.5" drive slots in them.  (There is a section of the forum devoted to cases...)  You should look for MBs with at least six SATA connectors and 3 PCI slots.  IF you are not looking to run a ton of Dockers of VMs, you can use older low-end hardware as far as core count goes.  If you have one of your old desktop PC's made in the last twelve years, it will be more than for a simple Unraid NAS with few Docker containers running as long as your not transcoding more than one thread!

 

EDIT:  I see I didn't mention my cases.  Both servers use Antec 900 server cases.  These cases will house between nine and fifteen 3.5" HD in 'hot-swap' cages but the capacity of the latest HD's, you could easily build a server with sixty-plus TB of parity protected storage space in a four drive case. 

 

Edited September 6, 20241 yr by Frank1940

15 hours ago, JonathanM said:

Most people just use a normal desktop type computer, size depending on how many disk drives you anticipate. Disk cooling is a critical consideration.

 

A normal 4U rackmount server is also popular for very powerful builds.

 

Ah - so normal desktop motherboards expose their SATA and PCIe ports? I only ask because I'm using my "normal" laptop, and it doesn't have any of those connections. All it has is USB-C / A ports. 

 

Final question, if you only have 6 SATA, ports, let's say, is there a way to connect more than 6 hard drives? I'm sure there are, but what are the options, and how much would they degrade performance? 

36 minutes ago, stevenxl said:

Final question, if you only have 6 SATA, ports, let's say, is there a way to connect more than 6 hard drives? I'm sure there are, but what are the options, and how much would they degrade performance?