Trouble using SDXC 128GB card

[Musbur]

Hello,

I'm using a Lenovo Thinkpad T480s. Recently I bought a SanDisk Extreme
Pro 128GB SDXC card for my digital camera, but I quickly found out that
the system can't work with that card. It show up as /dev/sdb, I can use
fdisk and everything without error, but when remove and re-insert the
card, the partition table is gone. When I boot the computer in Win10
(latest version), the card shows up as 'SDXC' but cannot be accessed.
The camera can format, read and write just fine.

According to the specs, the builtin card reader of the T480s is SDXC
compatible. Is there a driver for Linux that can make this card work?
The BIOS of the computer has just been updated a week ago. Is the
hardware just not compatible?

Needless to say, my SDHC cards (up to 32GB) work fine in this machine.

[Dan Ritter]

It's is quite plausible that you have a counterfeit card, with
an actual capacity of 8-16GB.

Try this (assuming it's still /dev/sdb when you plug it in):

mkfs.ext4 /dev/sdb
mkdir /mnt/tmpcrd
mount /dev/sdb /mnt/tmpcrd

Now download something big, like

wget https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-11.1.0-amd64-netinst.iso

which is 378MB.

for i in `seq 1 200`; do cp debian-11.1.0-amd64-netinst.iso \
/mnt/tmpcrd/file.$i; done

That will get you 200 files on the SD card, each 378MB, for a total of about
75,600 MB, which is more than half the capacity of the disk.

Next:

sync
umount /dev/sdb

pull the card out, pop it back in.

mount it at /mnt/tmpcrd again.

Debian says the SHA256 hash of that file is
02257c3ec27e45d9f022c181a69b59da67e5c72871cdb4f9a69db323a1fad58093f2e69702d29aa98f5f65e920e0b970d816475a5a936e1f3bf33832257b7e92

so let's calculate it for the last 20 files:

for i in `seq 180 200`; do sha256sum /mnt/tmpcrd/file.$i; done

You should get 20 copies of the same hash as above. If you don't
-- you have a a defective, possibly counterfeit card.

-dsr-

[David Wright]

On Tue 26 Oct 2021 at 15:41:33 (+0000), Musbur wrote:
> I'm using a Lenovo Thinkpad T480s. Recently I bought a SanDisk Extreme
> Pro 128GB SDXC card for my digital camera, but I quickly found out that
> the system can't work with that card. It show up as /dev/sdb, I can use
> fdisk and everything without error, but when remove and re-insert the
> card, the partition table is gone. When I boot the computer in Win10
> (latest version), the card shows up as 'SDXC' but cannot be accessed.
> The camera can format, read and write just fine.

Perhaps the first thing to figure out is the filesystem being used
by the camera, otherwise I assume the card is useless. The default fs
for such a card is exFAT, and the camera might just force that to
be the case if it dislikes what you feed it.

> According to the specs, the builtin card reader of the T480s is SDXC
> compatible. Is there a driver for Linux that can make this card work?
> The BIOS of the computer has just been updated a week ago. Is the
> hardware just not compatible?

The kernels in bullseye support exFAT, but older releases will require
the exfat-fuse and exfat-utils packages. Apparently bullseye can still
use exfat-fuse with the new exfatprogs package, but I've not tried
that.¹

> Needless to say, my SDHC cards (up to 32GB) work fine in this machine.

Yes, because they're probably formatted as vfat.

¹ I toyed with exFAT as a Windows/linux shared backup format, but the
advantages weren't sufficient to counter the complications.

Cheers,
David.

[David Christensen]

Please post a complete console session (prompts displayed, commands
entered, output displayed) that demonstrates the issues.


David

[Anssi Saari]

Musbur <mus...@posteo.org> writes:

> According to the specs, the builtin card reader of the T480s is SDXC
> compatible. Is there a driver for Linux that can make this card work?
> The BIOS of the computer has just been updated a week ago. Is the
> hardware just not compatible?

As Windows 10 can't access the card either then it seems likely your
hardware is not compatible. Curious though. For example,
https://www.notebookcheck.net/First-Impressions-Lenovo-ThinkPad-T480s-i5-WQHD-Laptop.284832.0.html
tested SDXC card performance on T480s. I guess it's possible your
specific T480s has a different card reader. Maybe you can check the
laptop's specific configuration with its serial number?

Well, external card readers are cheap and one assumes your camera can
connect to the PC with USB.

[Dieter Rohlfing]

Am Tue, 26 Oct 2021 15:41:33 +0000
schrieb Musbur <mus...@posteo.org>:

>I'm using a Lenovo Thinkpad T480s. Recently I bought a SanDisk Extreme
>Pro 128GB SDXC card for my digital camera, but I quickly found out that
>the system can't work with that card.

>.....

>The camera can format, read and write just fine.

Perhaps this link

https://github.com/ThomasKaiser/Knowledge/blob/master/articles/A1_and_A2_rated_SD_cards.md#application-performance-class-2-a2

may explain, why you have these problems.

Specially the following text is interesting:

>Application Performance Class 2 (A2)
>A2 promises even better performance with 4000/2000 read/write IOPS
>minimum but there's a problem since as outlined by the SD Association A2
>cards show "much higher performance than A1 performance by using
>functions of Command Queuing and Cache".
>
>Cache and Command Queuing require host (driver) support since the host
>needs to activate those new features first. The cache feature on A2 rated
>cards makes use of volatile RAM on the card requiring the host to learn
>new commands to issue flushing the cache (involving the risk of data
>losses -- for details see especially chapter 4.17 in Physical Layer
>Simplified Specification 6.0)

For my raspi-like hosts I avoid to buy A2 cards. With my A1 sdxc cards I
have no problems (neither with a built-in card reader nor an USB card
reader).

[Musbur]

Hello all, thanks for the replies to this issue. I currently don't have
the time to delve into this any further, but I did format the card in my
camera and took a few 100 MB of video on it. The video plays back fine
on the camera itself, also after turning the camera off and removing and
re-inserting the card. So the card is OK, it just doesn't work on my
Lenovo T480s in both Debian 11 and Windows 10. I can write data to the
raw device (i.e., /dev/hdb) but it reads back only garbage, without
getting any I/O error. I suspect it has to do with the computer's
hardware. Still weird, given that SDHC cards work fine, and this is a
fairly recent machine with a brand-new BIOS update. I'll procure another
card reader and report back.

[Stefan Monnier]

Musbur [2021-10-29 07:40:09] wrote:
> I can write data to the raw device (i.e., /dev/hdb) but it reads back
> only garbage, without getting any I/O error.

Sounds like the plot of a Halloween movie for sysadmins.


Stefan