IMO, perfectly means there's no known restriction of file size on the media, so do you encounter it? Are you ble to copy complete 1080P movies? (Playing is no problem, though)

No, files over 4gb in size do not work. That's a restriction of Fat32.

ok, this S$#@ happened again, AGAIN
so i can count 3, THREE sdcard turned into garbage since i've used btrfs formated sdcard.

i don't know if it's a sd card bug, software bug, or jolla hardware bug, and it makes me very angry

Big btrfs partitions can have issues if you dont run btrfs balance command once in a while. So if you use 64GB cards actively then ext4 or exfat might be better choises (they dont have 4GB limitations).

64GB sd turning readonly usually happens on fake cards. So if your getting 64GB card, then I recomend bigger chains that give your lifetime warranty for the card if it would happen to fail.

all of those are genuine transcend card.
even one of those is a warranty exchange.

i'm mad

You are not alone and it is not only Transcent cards. And it is not Jolla either. I bought A Sandisk 128GB from Amazon (not a reseller that is fullfilled by amazon btw) so I am pretty sure it is genuine.

The card worked for one day and I have successfully formatted the card to btrfs and sharing the space between android and jolla following the guidelines at together.jolla.com. Everything was working fine. So next day I decided to move all my music/videos/photos to the card from ubuntu (through a card reader not through Jolla). And for the first few GBs it was smoothly doing what it had to do and suddenly the copying progress stucked.

Afterwards the whole sdcard was in read only mode not being able to do anything. SD Formatter on Windows says it is write protected no matter how many different microsd to SD adapters (with the lock trigger set to unlocked of course) I have used. Windows can't format either. Partition tools fail to actually make any change on the card. fdisk on linux says it creates a partition table but nothing is changed... dd is freezing my pc, gparted also fails and on some card readers I get I/O errors. Any symbian/android device I have tried failed to format the card. The same for my old and trusty N900.

I am going to return the card (so problem solved) but this whole mess really irritates me as sdcards where not like that. I remember 4-5 years ago I was buying the then expensive 8gb microsd (from Kingston) and they are still running with no problems after all these years no matter what I am doing with them. Used them in raspPi formatted them with not common FS (ReiserFS, Reiser4, Btrfs) and never had a problem.

Nowadays no matter what brand of sdcard I am getting I will always have to deal with their lies. Speeds are never what they are advertised (especially with Sandisk cards where class 10 cards are performing like class 4, but other brands like Kingston are doing the same). The QA seems to really went downhill the last few years with sdcards.

I had problems many years ago with mmc cards from not so popular brands and I knew it was the bad quality in them so I got my lesson and I am always buying branded stuff (especially kingston for SDs due to the lifetime warranty and transcent for mmc back then). Now no matter what the brand is, same story, and when you spend 70 pounds just for an sd card, that kind of behaviour is unforgivable.

i know that feel bro, i used to buy 2gb and 4gb "no hc" sd card when it was over 100e, because my pocket pc could not handle hc card, and they still works

how can someone sell sd card that cannot survive half a year ?
do they think it's like disposable razor, you use it a month or two, and trow it away? seriously?

I once bought an ADATA 32GB microSD for an old Android phone. Worked for a few months, and then conked out. Wouldn't mount on anything. And the company were impossible to contact. A few years ago those card capacities were quite expensive to I was annoyed to say the least.

Fortunately they're less expensive now and also more reliable, I might get either a 32GB or a 64GB now, but not a 128GB; too risky.

I chose to ditch btrfs from my 128GB sdcard and formatted it as ext4. So far so good. No issues yet. Music player works.

Ext4 is no issue for me, as I use almost exclusively Linux. Jolla masks the underlying filesystem when connected to a computer with USB cable, so for me all seems to be o.k. even when connected to windows. I have not tried to transfer over 4GB files, will do this when I have some time.

I'm also using a 128 GB card with ext4. If anyone has issues you can grab a newer /usr/sbin/mount-sd.sh from git. https://raw.githubusercontent.com/ne...ts/mount-sd.sh you can devel-su then move your mount-sd.sh to .bak and place that one in /usr/sbin