SATA Port JBOD compatible?

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SATA Port JBOD compatible?

Unread post by Catscrash » Mon Nov 26, 2018 3:13 am

Hi,

is the SATA Port of the H2 JBOD compatible? I have 4 drives in a case which is connectable via (e)sata, but not all devices support the jbod protocol, then they see only the first drive of the bunch, instead of all 4?

thanks

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Mon Nov 26, 2018 4:31 pm

Most probably you're talking about 'SATA port multiplier' compatibility here? Usually onboard Intel controllers do not support this but to be sure you need an answer from Hardkernel (rule of thumb: if there are no eSATA ports and the board is not advertised as 'PM capable' and ideally also talks about FIS vs. command based switching you better drop the idea)

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Re: SATA Port JBOD compatible?

Unread post by odroid » Mon Nov 26, 2018 5:09 pm

Is there any SATA-3(6Gbps) port multiplier in the market with a reasonable price range(<$50)?
If yes, we will buy one and test it.

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Re: SATA Port JBOD compatible?

Unread post by crashoverride » Mon Nov 26, 2018 6:13 pm

@odroid,
I searched for "JMB321" on amazon and there are many around the $20 range.
Image

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Re: SATA Port JBOD compatible?

Unread post by odroid » Mon Nov 26, 2018 6:37 pm

But that chipset seems to support SATA-2 3Gbps speed only. :)

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Re: SATA Port JBOD compatible?

Unread post by crashoverride » Mon Nov 26, 2018 6:54 pm

odroid wrote:that chipset seems to support SATA-2 3Gbps speed only.
The protocol should be the same despite the slower speed. If it does not work with the slower one, it will not work with a faster one.

This conclusion is based on JMicron product brief for JMB321 and JMB575.
http://www.jmicron.com/PDF/brief/jmb321.pdf
http://www.jmicron.com/PDF/brief/jmb575.pdf

Both state:
* Compliant with Serial ATA Port Multiplier Spec. Revision 1.2
* Compliant with Serial ATA Port Selector Spec. Revision 1.0

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Re: SATA Port JBOD compatible?

Unread post by crashoverride » Mon Nov 26, 2018 7:02 pm

I found some boards on ebay searching with "JMB575". They are also in the $20 range:
https://www.ebay.com/itm/SATA-Expansion ... 3825601006
Product master control: JMICRON JMB575

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Mon Nov 26, 2018 7:10 pm

odroid wrote:Is there any SATA-3(6Gbps) port multiplier in the market with a reasonable price range(<$50)?
The cheap JMB321 will do (and if this one works the 'better' JMB575 will work too): https://forum.armbian.com/topic/7962-es ... -feedback/

You need to keep in mind that if you run into troubles with an el cheapo JMB321 that overheating could be the culprit and that PMs that support only CBS tell nothing about the capabilities to interact with the way better (faster) FIS based switching PMs: http://forum.lemaker.org/forum.php?mod= ... &pid=64227

Edit: of course a lot of people will then do crazy things with such port multipliers like playing RAID-5 with them. Great recipe for data loss since usually people think 'if there's some redundancy then why backup?'.
Last edited by tkaiser on Mon Nov 26, 2018 7:19 pm, edited 1 time in total.

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Re: SATA Port JBOD compatible?

Unread post by odroid » Mon Nov 26, 2018 7:13 pm

crashoverride wrote:I found some boards on ebay searching with "JMB575". They are also in the $20 range:
https://www.ebay.com/itm/SATA-Expansion ... 3825601006
Product master control: JMICRON JMB575
It seems to be worth to try. I will order one tomorrow.

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Re: SATA Port JBOD compatible?

Unread post by puremind » Tue Nov 27, 2018 8:37 am

If any of those work... can we expect type V cases :) for 4+ drives :)
Odroid H2 Rev B, 16GB Ripjaws, MP510 Corsair 512GB Nvme

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Re: SATA Port JBOD compatible?

Unread post by odroid » Tue Nov 27, 2018 10:12 am

I've ordered two samples.
But it may take 3~6 weeks because there is no express shipping option. :(
Once we received it, we will share our test results.

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Re: SATA Port JBOD compatible?

Unread post by zupet » Tue Nov 27, 2018 12:09 pm

I found these from http://forum.asrock.com/forum_posts.asp ... r-question
http://www.intel.com/content/www/us/en/ ... sheet.html

But I can tell you that searching this document for the term "port multiplier", provides these hits on pages 464 and 537:

The PCH SATA controller does not support Port Multipliers.

The PCH sSATA controller does not support Port Multipliers.
It's from different chipset but Intel nerver supported SATA port multiplier since it was part of PCH.

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Re: SATA Port JBOD compatible?

Unread post by odroid » Tue Nov 27, 2018 1:25 pm

It seems to be true. But I just wanted to confirm the incompatibility.

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Re: SATA Port JBOD compatible?

Unread post by Catscrash » Tue Nov 27, 2018 4:13 pm

Thank you a lot for testing, I'm looking forward to the results :-) Maybe we are surprised positively :-)

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Tue Nov 27, 2018 6:37 pm

odroid wrote:Once we received it, we will share our test results.
Even if it doesn't work on the H2 as expected it would be great to attach it quickly to an N1* with 2 SSDs connected and check at least negotiated link speed and dmesg output for 0x197b:0x5755 (if it's 0x197b:0x0325 instead removing the heatsink would be funny).

When no working N1 (ASM1061) is around any Marvell SATA controller will do the job too. Maybe you already ordered one to be tested with H2's M.2 slot?

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Re: SATA Port JBOD compatible?

Unread post by odroid » Wed Dec 19, 2018 7:08 pm

We ordered a couple of JMB575 SATA multiplier boards.
It took over 20 days to receive the items via normal mail from China.
I couldn't find an option to choose a faster shipping in ebay store. :(

Anyway, it seems to be working nicely. :D
We connected 10 SATA storage devices and our initial test result looks fine.
https://wiki.odroid.com/odroid-h2/appli ... ata_drives

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Wed Dec 19, 2018 7:57 pm

odroid wrote:JMB575 SATA multiplier boards ... We connected 10 SATA storage devices and our initial test result looks fine.
https://wiki.odroid.com/odroid-h2/appli ... ata_drives
That's really great news!

Did you test simultaneous access to all 10 disks with something 'better' than the dd call you used (omitting bs and therefore testing with 512 byte chunks which is very slow by design)?

Edit: @odroid: to elaborate on the latter: you currently use dd if=/dev/sd? of=/dev/null which means you 'benchmark' with dd's default block size which is just 512 byte. As we all (should) know small block sizes correlate with slow transfer speeds. It should be pretty obvious when looking at any real storage benchmark testing through various different block sizes, e.g. your own iozone measurements. Transfer speeds with just 4096 byte block size are magnitudes lower than those with larger block sizes. 'Benchmarks' that work with just 512 byte will show even worse speeds for sure. So while the test you're currently running is a great stress and reliability test you might want to repeat the test with more realistic large block sizes to check for performance implications with your SATA PM setup: dd if=/dev/sd? of=/dev/null bs=16M

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Re: SATA Port JBOD compatible?

Unread post by Catscrash » Thu Dec 20, 2018 7:42 am

Amazing, thank you so much. I'm looking forward to being able to buy again

Best regards

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Re: SATA Port JBOD compatible?

Unread post by odroid » Thu Dec 20, 2018 8:33 am

tkaiser wrote: your SATA PM setup: dd if=/dev/sd? of=/dev/null bs=16M
Thank you for the suggestion.
We will try it in the middle of next week.

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Re: SATA Port JBOD compatible?

Unread post by gokuz » Fri Dec 21, 2018 12:56 pm

odroid wrote:
Wed Dec 19, 2018 7:08 pm
We ordered a couple of JMB575 SATA multiplier boards.
It took over 20 days to receive the items via normal mail from China.
I couldn't find an option to choose a faster shipping in ebay store. :(

Anyway, it seems to be working nicely. :D
We connected 10 SATA storage devices and our initial test result looks fine.
https://wiki.odroid.com/odroid-h2/appli ... ata_drives
For your 10 drive stress test, it looks like its prioritizing the earlier commands. This is curious as it could be the fault of how the chipset works or the software itself.

Even so, quick maths shows 462MB/s is the total saturation for 10 drives which is weird to me. You tested a single ssd and it shows 550MB/s which is correct.

1 Port sata gives 6Gb/s=750MB/s
You are using 2 port sata so it has a theoretical speed of 1500MB/s combined.

What I would do next is,
  • 1. plug in just only 2 SSDs on each multiplier board
    2. Plug in just 1 multiplier first and test > check if it reaches 750MB/s total theoretical speed
    3. Plug in both multiplier and test > check if it reaches 1500MB/s total theoretical speed
Also any updates on m.2 to pcie? Could you test a daughter board to pcie card instead. The board you tested might be the fault here.
4 lanes of pcie should not go to waste on a nvme drive tbh.

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Fri Dec 21, 2018 4:26 pm

gokuz wrote:
Fri Dec 21, 2018 12:56 pm
You tested a single ssd and it shows 550MB/s
With a block size of 16777216 bytes (16 MB). What Hardkernel guys now do is testing with block sizes 32768 times smaller: just 512 byte for whatever reasons. So everything as expected when 'benchmarking' is done with problematic tools like dd (hdparm is another such tool users don't understand why it sucks today).

Just have a look at Hardkernel's or my iozone results that were generated with a bunch of different block sizes: https://github.com/ThomasKaiser/Knowled ... erformance (the two SATA SSDs 'score' not even 100 MB/s reading at 4K block sizes, now imagine what would happen when measuring with just 512 bytes)

It should be obvious that those transfer speeds measured fully depend on the block sizes used and that you need to exceed 1MB (e.g. 16MB) to get maximum numbers. While that's not that realistic wrt real-world workloads it's the standard way to generate those MB/s numbers.
Last edited by tkaiser on Fri Dec 21, 2018 8:08 pm, edited 2 times in total.

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Re: SATA Port JBOD compatible?

Unread post by gokuz » Fri Dec 21, 2018 4:36 pm

tkaiser wrote:
Fri Dec 21, 2018 4:26 pm

With a block size of 16777216 bytes (16 MB). What Hardkernel guys now do is testing with block sizes 32768 times smaller: just 512 byte for whatever reasons. So everything as expected when 'benchmarking' is done with problematic tools like dd (hdparm is another such tool users don't understand why it sucks today).
TBH I'm only interested in Sequential with block size 128KiB. Like most people, I deal with huge files so this test is the best to saturate SSD.

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Fri Dec 21, 2018 4:57 pm

gokuz wrote:
Fri Dec 21, 2018 4:36 pm
I'm only interested in Sequential with block size 128KiB.
Well, anyway. I hope you're getting that when you look at Hardkernel's test results you see sequential transfer speeds with a block size of just 512 byte which are magnitudes lower compared to any reasonable transfer speed test. And I doubt that you will see the full 550 MB/s these Intel SATA ports are known for when testing with 128KiB but hey...

BTW: when doing your math you should try to adapt it to the technology you're talking about. 6 Gbps with SATA III does not result in theoretical 750 MB/s but 600 MB/s (8b10b coding is used here).

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Re: SATA Port JBOD compatible?

Unread post by gokuz » Fri Dec 21, 2018 5:08 pm

tkaiser wrote:
Fri Dec 21, 2018 4:57 pm
BTW: when doing your math you should try to adapt it to the technology you're talking about. 6 Gbps with SATA III does not result in theoretical 750 MB/s but 600 MB/s (8b10b coding is used here).
You do know 750MB/s = 6Gbps right? The exact amount. Like having 10* 10c coins will get you $1.
I'm not putting in any headroom here, just purely theoretical speeds.

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Fri Dec 21, 2018 5:18 pm

gokuz wrote:
Fri Dec 21, 2018 5:08 pm
tkaiser wrote:
Fri Dec 21, 2018 4:57 pm
BTW: when doing your math you should try to adapt it to the technology you're talking about. 6 Gbps with SATA III does not result in theoretical 750 MB/s but 600 MB/s (8b10b coding is used here).
You do know 750MB/s = 6Gbps right? The exact amount. Like having 10* 10c coins will get you $1.
Let's simply stop here as I already mentioned what's wrong with your math (ignoring the technology you deal with -- surprisingly with PCIe Gen2 also using 8b10b coding you got it to divide by 10 and not by 8 to get from signal to data rate. If you want to confuse signal rate with data rate that's perfectly fine but not a discussion I want to participate in)

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Re: SATA Port JBOD compatible?

Unread post by gokuz » Fri Dec 21, 2018 5:22 pm

tkaiser wrote:
Fri Dec 21, 2018 5:18 pm
gokuz wrote:
Fri Dec 21, 2018 5:08 pm
tkaiser wrote:
Fri Dec 21, 2018 4:57 pm
BTW: when doing your math you should try to adapt it to the technology you're talking about. 6 Gbps with SATA III does not result in theoretical 750 MB/s but 600 MB/s (8b10b coding is used here).
You do know 750MB/s = 6Gbps right? The exact amount. Like having 10* 10c coins will get you $1.
Let's simply stop here as I already mentioned what's wrong with your math (ignoring the technology you deal with -- surprisingly with PCIe Gen2 also using 8b10b coding you got it to divide by 10 and not by 8 to get from signal to data rate. If you want to confuse signal rate with data rate that's perfectly fine but not a discussion I want to participate in)
Ita already understood that 6Gbps will never reach 750MB/s for the reasons that you said. The number itself is there for a reason. Just like how 1TB is not pure 1TB. Simply understood by many.

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Fri Dec 21, 2018 5:37 pm

gokuz wrote:
Fri Dec 21, 2018 5:22 pm
750MB/s
Now mentioning the 'magical' difference between signal rate and data rate (8b10b coding) the 3rd time: https://en.wikipedia.org/wiki/Serial_AT ... l_ATA-600)

The theoretical maximum you could get with SATA III is 600 MB/s but of course you'll never reach this in reality (same when comparing theoretical interface signal/data rates like PCIe and 10GBase-T but that's a different confusion)

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Fri Dec 21, 2018 7:23 pm

tkaiser wrote:
Wed Dec 19, 2018 7:57 pm
So while the test you're currently running is a great stress and reliability test.
I'm not that convinced any more that your currently running dd if=/dev/sd? of=/dev/null test is that useful (or even useful at all). You read below the filesystem layer and you send the data to /dev/null immediately. How should it be possible to detect data corruption / bit rot with such a test?

If such a long-term test should provide reliability insights I would assume checking for data corruption is essential. If you're running with Ubuntu 18.04 or 18.10 most probably the easiest way to check for data integrity is to create a striped zpool to later get warnings when data corruption might occur when testing above the filesystem layer:

Code: Select all

cd /dev/disk/by-id/
for i in ata-* ; do
	parted $i mklabel gpt
done
mkdir /mnt/stripeset
zpool create -m /mnt/stripeset stripeset ata-*

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Re: SATA Port JBOD compatible?

Unread post by fvolk » Mon Dec 24, 2018 6:46 am

odroid wrote:
Wed Dec 19, 2018 7:08 pm
We ordered a couple of JMB575 SATA multiplier boards.
We connected 10 SATA storage devices and our initial test result looks fine.
The spec says the JMB575 supports staggered spin-up and almost new 2.5" mechanical drives are cheaply available due to laptops being upgraded to SSDs.
Would such a multiplier board work with several 2.5" disks with the original 60W power supply, if spin-up (=peak power) is staggered?

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Re: SATA Port JBOD compatible?

Unread post by joshua.yang » Mon Dec 24, 2018 6:04 pm

We have tested with dd if=/dev/sd? of=/dev/null bs=16M status=progress command.

Specifying block size as 16M couldn't increase their's transfer speed. It looks like they're barely differences with the default settings that have block size 512 bytes. :shock:
I had tried 8M but it didn't affect either.

Please see the attached screenshots.
h2-10sata-dd-parallel-bs16m-1.png
h2-10sata-dd-parallel-bs16m-1.png (2.07 MiB) Viewed 4421 times
h2-10sata-dd-parallel-bs16m-2.png
h2-10sata-dd-parallel-bs16m-2.png (803 KiB) Viewed 4421 times

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Re: SATA Port JBOD compatible?

Unread post by gokuz » Mon Dec 24, 2018 6:08 pm

Please try only 4 ssd. 2 SSD each.

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Mon Dec 24, 2018 8:31 pm

joshua.yang wrote:
Mon Dec 24, 2018 6:04 pm
We have tested with dd if=/dev/sd? of=/dev/null bs=16M status=progress command.
Thank you for the numbers. Wondering whether all the disks are SATA III capable or some only SATA II (since I read in some review that JMB575 then limits all disks to lowest negotiated SATA version). Can you provide SMART data of the disks, please?

Code: Select all

apt install smartmontools
for i in /dev/sd* ; do
	smartctl -q noserial -s on -a $i
	echo -e "\n\n\n"
done | curl -F 'f:1=<-' ix.io

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Re: SATA Port JBOD compatible?

Unread post by lazlo » Thu Dec 27, 2018 7:19 pm

Could it be that 10 drives running 10 threads over saturates the CPU causing the " %iowait " to bottleneck the benchmarks? Test this with sysstat's 'iostat' command.

1.) Open a terminal and execute "iostat -m 1" and then adjusting the size of the window as needed ;-)

2.) Start the first test with dd and wait for 5 seconds before launching to the second test, then wait 5 seconds before launching the 3rd test, and so on.

3.) Look for the number of threads needed for iostat's %iowait stat to go over 25%, 50%, 75%, and 100%

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Thu Dec 27, 2018 7:47 pm

lazlo wrote:
Thu Dec 27, 2018 7:19 pm
running 10 threads over saturates the CPU causing the " %iowait " to bottleneck the benchmarks?
How should %iowait be related to an oversaturated CPU?

Anyway, since Hardkernel does not provide more information the only learning so far is

* unlike Intel SATA host controllers living in the PCH the ones in Gemini Lake SoCs support SATA port multipliers
* performance is crap
* reliability has not been tested

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Re: SATA Port JBOD compatible?

Unread post by lazlo » Thu Dec 27, 2018 7:52 pm

tkaiser wrote:
Thu Dec 27, 2018 7:47 pm
How should %iowait be related to an oversaturated CPU?
If you wait long enough...I might tell you. :-P

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Re: SATA Port JBOD compatible?

Unread post by joshua.yang » Mon Dec 31, 2018 4:38 pm

tkaiser wrote:
Mon Dec 24, 2018 8:31 pm
joshua.yang wrote:
Mon Dec 24, 2018 6:04 pm
We have tested with dd if=/dev/sd? of=/dev/null bs=16M status=progress command.
Thank you for the numbers. Wondering whether all the disks are SATA III capable or some only SATA II (since I read in some review that JMB575 then limits all disks to lowest negotiated SATA version). Can you provide SMART data of the disks, please?

Code: Select all

apt install smartmontools
for i in /dev/sd* ; do
	smartctl -q noserial -s on -a $i
	echo -e "\n\n\n"
done | curl -F 'f:1=<-' ix.io
Sorry for late reply.

Here are the results: http://ix.io/1xbf
Only one device WD 500GB Blue runs on SATA 3.0 but as 3.0 Gbps speed.
So I tried out dd again except that drive and,
1. The first dd running drive kept over 250 MB/s even after the remaining drive ran dd command.
2. I closed dd command on the first drive and ran that again, then the transfer speed of all of 4 drives is about 60 MB/s. Still abnormal.
lazlo wrote:
Thu Dec 27, 2018 7:52 pm
Could it be that 10 drives running 10 threads over saturates the CPU causing the " %iowait " to bottleneck the benchmarks? Test this with sysstat's 'iostat' command.

1.) Open a terminal and execute "iostat -m 1" and then adjusting the size of the window as needed ;-)

2.) Start the first test with dd and wait for 5 seconds before launching to the second test, then wait 5 seconds before launching the 3rd test, and so on.

3.) Look for the number of threads needed for iostat's %iowait stat to go over 25%, 50%, 75%, and 100%
I tried that after executing iostat -m 1 then run dd command for one by one with 5 seconds intervals, but %iowait stat doesn't go over 75. Sometimes it gets up to 70~73%.
And it reached 25% by only one drive, and 50% by 3~4 drives.

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Re: SATA Port JBOD compatible?

Unread post by lazlo » Mon Dec 31, 2018 7:11 pm

What happens if you read /dev/zero and write to ./testfile? I think that might make the throughput and %iowait both increase. That is assuming that writing to /dev/null doesn't actually write anything to the drives. Because there is no unwritten data (and therefore no unsafe data) the read and write operations would be both interruptible.

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Re: SATA Port JBOD compatible?

Unread post by tkaiser » Mon Dec 31, 2018 7:28 pm

joshua.yang wrote:
Mon Dec 31, 2018 4:38 pm
Here are the results: http://ix.io/1xbf
Only one device WD 500GB Blue runs on SATA 3.0 but as 3.0 Gbps speed.
As a side note: this drive has an LCC issue (check attributes 4 and 193 and do a web search for 'wd lcc issue'). One 6TB WD RED has rather high CRC errors (attribute 199), in case this value increases with further testing there's a cabling problem and/or PM port problem (which can of course negatively affect performance since retransmits occur when CRC errors are detected).

Asides that, let's stop here. I don't get what you're testing but obviously no reliability testing will happen... (checking also for data integrity which requires testing above the filesystem layer and using a 'checksummed' fs like ZFS or btrfs).

Final note: I would also check dmesg output for an indication in which mode the PM operates: CBS or FIS based switching...

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Re: SATA Port JBOD compatible?

Unread post by C2H2 » Sat Jan 12, 2019 7:44 pm

Hello everybody,

what needs to be set in the bios for the controller to work? Only one drive is recognized at a time. (googletranslator)

Hallo zusammen,

muss was bestimmtes im Bios eingestellt werden, damit der Controller funktioniert? Es wird immer nur ein Laufwerk erkannt.

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Re: SATA Port JBOD compatible?

Unread post by C2H2 » Tue Jan 15, 2019 7:39 pm

It was not because of the Bios configuration. Ubuntu detects all drives. Windows 10 recognizes only one. I suspect that it is the ahci driver. Is there a solution?(googletranslator)

Es lag doch nicht an der Bios konfiguration. Ubuntu erkennt alle Laufwerke. Windows 10 erkennt aber nur eins.Ich vermute, dass es am ahci-Treiber liegt. GIbt es da eine Lösung?

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