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#1 2020-02-10 00:24:19

freefreeno
Member
Registered: 2019-03-07
Posts: 35

External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

I have nvme inside the laptop and also a Startech M2E1BMU31C external nvme drive enclosure. In KDE inside the kinfo application it list the partitions on the PM981a NVMe Samsung drive as sda1,sda2,and sda3. Also in lsblk it list them the same way. Can someone tell me what is going on and why nvme partitions being listed as sda ??? I thought nvme drives should always be shown as nvme0n1 and the partitions listed as nvme0n1p1,nvme0n1p2 and so on.

The external drive holder is this one:
https://www.startech.com/HDD/Enclosures … U31C#dnlds
https://www.startech.com/media/products … asheet.pdf

Last edited by freefreeno (2020-02-11 03:14:09)

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#2 2020-02-10 00:42:37

progandy
Member
Registered: 2012-05-17
Posts: 5,184

Re: External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

This doesn't look like a thunderbolt enclosure, but USB 3.1 Gen2. It probably uses UAS to transfer data from the nvme disk to the computer.


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#3 2020-02-10 02:22:17

freefreeno
Member
Registered: 2019-03-07
Posts: 35

Re: External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

It is an enclosure and holds only nvme drives and is not backwards compatible with sata so how or why is it calling my nvme drive sda ?? I am only wanting to know why it is calling my nvme ssd a sda .
Maybe some of my terms are incorrect but I am only wanting to know why a nvme drive is being called sda .

https://www.startech.com/media/products … asheet.pdf

This compact M.2 NVMe SSD Enclosure for PCIe SSDs is a highly portable, high-performance data storage
solution for your USB-C or Thunderbolt 3 enabled devices.
Unparalleled Performance
Leverage the high speeds of your M.2 NVMe drive, with this external SSD enclosure. It delivers USB 3.1
Gen 2 read/write speeds up to 10Gbps, which is nearly twice the capability of traditional M.2 SATA
enclosures and USB 3.1 Gen 1. NVMe allows users to take full advantage of the throughput available to
USB 3.1 Gen 2, which would not be possible with a SATA drive.

Connected with thru JHL7540 Titan RidgeThunderbolt 3 USB on Dell Precision 7540. I only have two thunderbolts and two regular style USB ports.

My PC has:
2 Thunderbolt™ 3 USB Type-C ports
2 USB 3.1 Gen 1 ports (1x power enabled)

https://www.dell.com/en-us/work/shop/la … 540-laptop

Last edited by freefreeno (2020-02-10 02:44:09)

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#4 2020-02-10 11:54:39

sabroad
Member
Registered: 2015-05-24
Posts: 242

Re: External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

progandy wrote:

This doesn't look like a thunderbolt enclosure, but USB 3.1 Gen2

freefreeno wrote:

I am only wanting to know why a nvme drive is being called sda.
https://www.startech.com/media/products … asheet.pdf

As progandy said, that's a USB 3.x enclosure. The ASM2362 bridge interfaces the media as USB storage.

NVMe <-> PCIe <-> ASM2362 <-> UASP <-> USB

--
saint_abroad

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#5 2020-02-10 16:36:23

progandy
Member
Registered: 2012-05-17
Posts: 5,184

Re: External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

sabroad wrote:
NVMe <-> PCIe <-> ASM2362 <-> UASP <-> USB

And UASP is recognized as an SCSI device by linux (the long name is "USB attached SCSI protocol"). SATA and SCSI both use the sdX prefix.
UASP is able to use the full 10GBps of a USB3.2Gen2 port, which is faster than SATAIII (6GBps), and slower than "SATA Express 16GBps - 2 lanes".
Considering the USB overhead it is probably about on par with "SATA Express 8GBps - 1 lane" or a bit faster.
Of course it is still significantly slower than NVME (up to 32GBps) or thunderbolt3 (4x8GBps pcie lanes -> 32GBps)

Edit: Often thunderbolt3 only has 2 pcie lanes, so 16GBps total, so I'd guess UASP is about half to 2/3 the speed you could typically achieve with NVME connected via thunderbolt3.

Last edited by progandy (2020-02-10 16:39:02)


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#6 2020-02-10 19:35:57

freefreeno
Member
Registered: 2019-03-07
Posts: 35

Re: External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

So I guess the answer is yes nvme will show as sda thru uasp. Thanks

Last edited by freefreeno (2020-02-10 19:37:37)

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#7 2020-02-10 19:38:49

progandy
Member
Registered: 2012-05-17
Posts: 5,184

Re: External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

Yes. You are not connecting an NVME drive directly to the PCI bus. You are connecting an NVME drive to a chip in your enclosure. This chip then communicates via USB with the computer. The protocol it uses for that is recognized as an SCSI variant by linux. Therefore it will be named with sdX.

Edit: Ninja'd

Last edited by progandy (2020-02-10 19:40:06)


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#8 2020-02-11 02:32:23

freefreeno
Member
Registered: 2019-03-07
Posts: 35

Re: External nvme thunderbolt enclosure shows sda1,sda2,sda3 [SOLVED]

Thanks and can someone give me the link on the info to mark threads as solved because on the last one they left me a dead link. So I guess I really purchased the wrong thing. I wanted thunderbolt nvme drive holder and this was sold to me as a thunderbolt enclosure by Dell.

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