yashsingh1/xdaforums huggingface dataset:
[Android General] hrsh45:
i bought a SanDisk Extreme 64GB, its supposed to have reading speed 90MB/s,

but when i use h2testw to test the sd card in SanDisk adapter, it shows to have reading speed 65 MB/s , does that mean its a fake sd card?

thanks in advance
[Android General] NYLimited:
H2TestW is not ideal for testing read/write speeds which vary a great deal depending on many, many factors. If this app came up with errors while testing the card I might be concerned. For checking speed you'd be better off trying some of the benchmark programs listed in, I think, post 1. Keep in mind that manufacturer rating is the maximum number that can be achieved under ideal circumstances.
[Android General] thorw4ld:
Hi!

useful guide! I'd like to format my samsung pro 32 gb sdcard using f2fs though, and i have no idea how to do it with correct erase / write blocksize. The tools mentioned are only for fat / ext. Or did I miss something, is it not something i have to think about when using f2fs?
[Android General] NYLimited:
I guess it all depends on your OS - does it support f2fs currently? If not, this may not be a good idea.

If the OS can read/write the f2fs format you can use parted to re-partition the card completely and format it with mkfs something like:

mkfs.f2fs -l f2fs /dev/block/mmcblk0p2

and replace the mmcblk designation with your card's. There may be some f2fs tools available for Windows as well but I have not looked. In any event, make sure it is supported by your OS and have current backups, just in case. ;)
[Android General] chrcol:
my rom according to dev supports f2fs and indeed my cache is f2fs but if i format my sdcard as f2fs it shows as corrupted the repair process formats it as ext4. so samsung created f2fs and also dont support it?
[Android General] mirabilos:
f2fs is for NAND flash.

SD cards, on the other hand, emulate hard discs and don’t expose the underlying flash media directly, which allows them to use a plethora of standard filesystems.
[Android General] morpheous1777:
SD card issue

OREO 8.1 SECURITY UPDATE FEB 1ST 2019, getting notifications about LEXAR CARD IS MISSING, I reinsert and it shows again and mounts ok but after a while it unmounts again and says it's missing again, if I reboot it's there for a while then disappears again, it's not the card it reads ok on computer no bad blocks and card has solid connection (not loose or wiggling), what app or system program controls the card auto mount?
[Android General] nonreality:
I hope that this question is somewhat new here. I want to put a 512 gb micro SD on my Note 9 and was wondering how to do it correctly. I have a 128 in now but want to add my own music collection to it thus the bigger card.

What I don't know is how Android 9 handles the portions of apps that have been installed there. Do I need to copy the whole card to a hard drive and then copy it to the new one or does Android do that on its own. I know that I need to move any pictures, I'm just not sure how to make sure those certain apps still work.

If there is an easy way to tell which apps have parts on the card I could reverse it but I haven't found a way to easily tell.

Thanks for any ideas in advance,

Terry
[Android General] zputnyq:
IMO, the easiest way to keep apps working while micro sd is changed, is moving the apps from external storage (micro sd) to internal storage first before change the micro sd card, then move it back to external. But of course, the internal storage must have enough room for the apps.
[Android General] NYLimited:
I would try to simply copy (not move!) *all* content from the old card to the new one, on a PC or using something like Root Explorer in Android. You need to copy hidden directories. This process will leave your original card in tact in case you need to revert. Alternately the method [MENTION=5228018]zputnyq[/MENTION] outlined should work well also, albeit it'd take longer.
[Android General] CryogenLab:
Surprised there was an indepth guide to SD cards been wondering about my sandisk for awhile...
[Android General] NYLimited:
Wow! A great question but unfortunately my answer will be borderline. The reason I say that is the reasons for your problem can be many and there is no simple or single way to answer it correctly.

Let's go to the beginning. For a moment I was gonna question your card - is it a Mobile Ultra UHS I, Class 10? - but you also said you had the issue with another, Class 4 card.

Your phone's card bus is rated up to Class 10 as far I know (but not UHS-I). Cards generally should last you years, not months. So, let's see, some rethorical questions, you probably already asked yourself...

Are you using FAT32 only or also another file system like ext4? Keep in mind that FAT32 does not have much safety built into it so if the device crashes or runs out of power data can get damaged. ext4's journaling file system will keep you safer but problem can still occur.

.

Have you checked the card on a PC and/or Linux system? Was it, in fact, damaged? If it was damaged, which partition was damaged? FAT or ext? I know you said you checked, but is this each time or only once?

.

Have you tried to copy the entire FAT32 partition to a computer? The reason I said entire is that you may have one or two damaged files on the card which create the problem but the card itself looks OK. Not trying to be rude but are you using a cheap card reader on the PC when you format the card? I have heard of some of the 'lesser' devices creating problem while supposedly successfully completing the format.

.

Have you tried formatting the card with SD Formatter (assuming the data has been saved or is not recoverable)? It may help to restore the card although that will not tell us why it went bad. I don't really know Fat32format so I cannot suggest that it does not do a good job, however, SD Format was specifically designed for SD Cards and is known to be reliable. Likewise the Minitool software, if needed.

.

If cards keep getting corrupted we need to consider the possibility that the phone's card bus is having problems. I am assuming you did not recently install a new operating system or kernel. If you have you may wish to try another custom kernel or even another ROM to see if they help.

.

If you are using an ext4 type file system (in addition to FAT32) does your boot process check it before mounting? If you can, use a Linux system and run e2fsk with a -p option on the ext4 partition.

.

Lastly, yes, it is possible for two cards to become damaged even though it is not something that happens every day. Of course, you telling me they tend to be fine on the PC I would not put a lot of credibility into that option. :)

I know I gave you a lot of questions to ponder and no real solutions but your problem can be created by a number of things and you will need a patience and time to figure out which is the real culprit.
[Android General] NYLimited:
The (almost) last word on read-ahead buffers

For everyone reading the many posts which flat-out recommend the use of a specific buffer for a given card size.. There seems to be no end to these posts although the authors tend to change over time.

Please keep in mind that while I mention that I use a 16384KB buffer I also tell you that

you need to experiment in order to find what works for you

, your setup and and your installed apps & data. The point is that a specific setup may not work for you while it does for me. Most tend to agree that a (somewhat) bigger buffer is better. But that ain't necessarily so! Here's a quote from someone who likely knows more about Linux that you and I know put together:

See what I mean? Do not simply accept anyone's statement that a buffer of xxxx is best! Do your own diligence!
[Android General] rsngfrce:
Thanks for your reply and assistance! I will try to briefly respond to your questions...

The card I am now using is a SanDisk Mobile Ultra microSDXC 64gb class 10. The card came in SanDisk packaging. I have a single partition and it is fat32 formatted.

.

I have not checked the card each time Android reports a problem, but every time I have checked it, no problems have been found

.

Before formatting it the last time, I copied all the data off onto my computer and there was no issue copying any of the data. Windows reports a capacity of 59.4GB, 49.1GB used, 10.2GB free. I have never had any issues accessing any of the data on the card while the card is mounted (and it is only basically unmounted when Android decides to unmount it).

Don't worry about being rude, I don't take it that way and if your question doesn't apply to me, it may be helpful to someone else. The card reader I am using is the reader that is built in to my Lenovo computer, I don't believe that should be an issue?

.

I am about the format the card again and use sd formatter. I really appreciate you mentioning this program because I had never heard of it before. My understanding is that Windows cannot format a 64GB fat32 card so when I first got the card, I used the phone itself to format the card. The second time I formatted, I searched around for what seemed to be the best option and ended up with fat32formatter, I never saw mention of sd formatter which surprises me!

.

.

No rom or kernel changes soon before this issue started occurring. It would seem there are many possible variables, but the only notable change I made right before this seems to have started was to install the V6 SuperCharger script. This is quite complex but mostly adjusts memory settings to my understanding. The only change it made regarding my sd card that I KNOW OF was to set the buffer to 2048, which is what I already had it set at anyway. However, since it is the closest thing I can remember to doing before this issue started, I am forced to be suspicious of it and it is probably the first thing I will try to remove to see if it clears up the issue for that reason.

Only fat32.

.

Really, I am pretty much convinced based on what I am seeing that the card is not damaged. To some degree, I wish it was, then I would at least know how to fix this issue ;) ! I have been thinking about this (within the extent of my limited knowledge) and it seems that it wouldn't be at all impossible for something to 'corrupt' the way the Android operating system is reading the card, causing it to then report the card is damaged, which clears up on reboot. I am basically trying to find out if that is logical? There are so many posts everywhere about Android telling people that there sd card is corrupt, but I haven't found a clear answer on the possibility that it is incorrect (for whatever reason or cause).

I am not very knowledgeable about logcat, but is there anything specific I might search for in a logcat after this issue occurs which might give me an indication of what is happening? Thanks again! :good:
[Android General] NYLimited:
I have heard of occasional problems with the Ultra cards, especially with the older phones like my HD2 which was not designed for cards that fast BUT you had the same issue with a Class 4 card. I don't suppose you have another Class 4 or 6 card to play with for a while..

OK, so it is not likely a bad spot on the card occupied by a file...

What, me worry?:D

Probably not.

It certainly should not hurt but, if your device is acting up it will not help either.. :(

I don't think that should create a problem but, depending on how much time you have to experiment, getting back to a clean ROM with nothing added might help narrow things down. Any chance of trying another kernel or ROM?

I have no basis for disagreeing (sigh)

Is it possible that the messages pop up after certain actions, perhaps the pressing of some key or part of the device? I am fishing for faulty hardware here.

The problem is that you would have to dump the log to /system if the sd card is acting up. Assuming you have room you can certainly try dumping and saving it so we can see what is near the end. The other things you can try (although I am not sure they will offer any more info) is getting a copy of dmesg and kmsg to see if there is anything in there. Never can tell. Again, if you try this after the card is acting up you will have to change the /sdcard/ to some other location in NAND.

su
dmesg > /sdcard/dmesg.txt
cat /proc/kmsg > /sdcard/kmesg.txt

or try

Lumberjack

.
[Android General] NYLimited:
Suddenly high battery usage may NOT be your card!

If you are located in the North East US where the hurricane has created havoc recently your sudden battery drain is probably not related to your card going bad. :)

T-Mobile has problems and several cell towers are either out or not operating correctly. I suspect other carriers may have similar issues also.

You can use

Tasker

to see what is going on. If you do not already have it, setup a profile and select STATE, CELL NEAR, SCAN and let it sit there for some 10 or more minutes. You will see your phone switching back and forth, getting weaker signal and generally expanding energy to find or keep a good connection.

So, don't be too quick blaming your SD Card for things. :cool:
[Android General] smb45:
Very Informative

I read through this thread once already and it was enlightening. I think I will probably dissect the posts when I begin tweeking my phone.

very impressive and comprehensive.

Thank you.
[Android General] rsngfrce:
In regards to reformatting my card with SDFormatter, I didn't figure it would help in my case (and it doesn't seem to have), but I figured I had nothing to loose but some time. However, I have to admit to being confused by SDFormatter, so maybe I didn't understand your OP on using it. The problem is that it offered no choice of format, and formatted my card as exFat, which was not what I wanted. So I then used Minitools to reformat it as Fat32, but I probably wasn't paying enough attention and Minitools set it as a logical partition and my phone didn't recognize it. I then used Easeus Partition Master (just because I am more familiar with it) to convert the (one and only) partition to primary.

That the card would have to be formatted in Fat32 using another app after being formatted by SDFormatter might be inferred from your OP, but I don't find this clear. :)
[Android General] NYLimited:
Ouch! I never had a 64GB card and didn't realize that SD Formatter was that 'smart'. Seems it determined the intended format for the card which was exFat. You are right - I never mentioned that since I didn't know it'd do that. Will have to update that post. :-[

I suspect they both will accomplish the intended task. You can set the partition to primary using either - I doubt it'll make much of a difference.

Not intended, not clear. You are absolutely right.

So, what next? This likely accomplished nothing, correct? Any chance of swapping cards with someone for a week? That may tell you something.

Any luck with the logs?

I have a feeling that if you take the phone back to have it checked they will find nothing in the short time they'll take.
[Android General] NYLimited:
Thanks for the kind words.

I hope you won't fall asleep reading it again... ;)
[Android General] Starcarr:
Thanks!

Really nice and worked info. Thanks
[Android General] Szczepanik:
EXT4 Partition

If you create an EXT4 partition using Minitools then I recommend that you format it again using 4EXT Recovery. This is particularly true for NativeSD. See the Wiki I wrote:

http://xdaforums.com/wiki/HTC_HD2/NativeSD

Note the plug for this thread in my Initial Requirements SD Card

Cheers

Tom
[Android General] NYLimited:
Much appreciated!

I have been meaning to try 4ext but the versions available for the HD2 are not up to date (I don't think the current touch version is available or planned at this time) Will have to do more reading during the weekend.

---

Spes in virtute est. (via XDA app)
[Android General] ilspinoza:
really useful :good:
[Android General] Dezmen:
Indeed, found really useful information about SD card!
[Android General] Paced98:
Thanks for this info
[Android General] NYLimited:
Glad it was a little help or, hopefully, at least interesting.

---

Live as if you were to die tomorrow. Learn as if you were to live forever. (via Tapatalk)
[Android General] NYLimited:
Did a little more reading tonight. If I am not mistaken the 4ext you are pointing to is the one I downloaded from Xylograph's server. It is an older version, text based, not touch. Am I correct? If yes, I played with it briefly but I was hoping that eventually the current touch version would be ported to the hd2.

Anyway, I am curious what makes 4ext better than, say, CWM Recovery 5.5.0.4 which works fine for my backups. Or TWRP if Arif-Ali updates it. In your opinion, I don't need a scientific comparison.

---

Live as if you were to die tomorrow. Learn as if you were to live forever. (via Tapatalk)
[Android General] marcopolo:
I never read this much after my college :P but now I am, I have been on Windows devices for a long and kind of ignored android before Froyo but now I am very much into it and thinking to jump in Linux as well.

After reading all about SD, Swap, journaling, File Systems... I guess I should get into it full time.

Thanks for your very precious time towards educating us :D
[Android General] rsngfrce:
Well, I got the SD corrupt notification again shortly after the 2nd reformat with SD Formatter/Minitools/Easeus, so it didn't seem to matter in my case. I have not yet gone the logcat route, the strange thing (and this may actually be indicitive) is that I never have this issue arise while I am using the phone... it's pretty much always a case of unlocking my phone to use it and finding that tbe SD card has been unmounted due to 'damage', so looking toward the end of a logcat wouldn't help.

As of right now, I haven't had the damaged card issue for several days, so I am HOPING that it has gone away in the same way it came, for whatever reason. If it starts occuring again, your suggestion of trying a known good SD card for a while is a good one, that may be my next step.
[Android General] Szczepanik:
Recovery

You are correct, I recommend the one on Xylograph's server because he wrote the book and it works!

Xylograph does list various recoveries including CWMTouch, CWR and TWRP so you can use whichever best suits you. Note Team Win Recovery Project Updated to 2.3. However, for NativeSD you do not spend much time using Recovery so 4EXT Recovery text based version is fine. See my Wiki http://xdaforums.com/wiki/HTC_HD2/NativeSD

If you have an HTC HD2 then I cannot recommend trying out NativeSD too highly. Once you have set up the EXT4 Partition, it is incredibly easy and works well.

Cheers

Tom
[Android General] NYLimited:
I tried most of the ones he posted. Admittedly I did not spend a lot of time on any of them. I was looking for a touch based app and 4ext didn't do that. TWRP versions he posted were nice but unfortunately they do not restore the boot partition on MagLdr based systems (although they work fine on cLK systems).

Tonight I'll probably end up playing with Tytung's new version. It is always something. :)
[Android General] NYLimited:
If you enjoy what you're doing it is generally fun, even if you end up putting too much time into occasionally. We all need to figure out how to split our time among the many things we want to and have to do. That is challenge! As for reading - that is a necessary evil in computers (and today's smart phones are just midget computers).
[Android General] tuth:
kips ;)

the phones' manufacturers suggestions are the best ones. for speed for long life and warranty.
[Android General] NYLimited:
What is partition alignment and why whould I need it?

There is a very good

article on partition alignment

if you are interested in knowing more about that subject - thanks

MarkAtHome

! I added the link to post 1 but figured I would mention it here for those already well past #1. :cool:
[Android General] dpcdpc11:
Finally a great guide to SD Cards!

Thank you for sharing this info!
[Android General] MrKalach:
Usable guide! It's help me.
[Android General] NYLimited:
Thanks for stopping by!
[Android General] tonycrew:
Thanks theres some good info there.
[Android General] naxwp:
These are valuable info :good :good:
[Android General] XxStatiX:
Very Informative! Thanks! :D
[Android General] Gses4us:
Great Info!

Great Info! I'm on the market for a new microsd, so this post is really helpful...thanx!
[Android General] NYLimited:
Much appreciated! I hope to update post 3 in the near future with some additional info that may be of interest. Thanks for stopping by!
[Android General] NYLimited:
SanDisk 16GB Micro SDHC Flash Card w/ Adapter Model SDSDQM-016G-B35A

Newegg just put the SanDisk 16GB Class 4 microSDHC SDHC Card with Adapter on sale for $9.99. This is model no. SDSDQM-016G-B35A.

Coupon code "HARDOCP11X8C" drops it to $5.99 with free shipping.

http://www.newegg.com/Product/Product.aspx?Item=N82E16820171491

That's $0.37/GB and a very low price for any SanDisk 16GB microSDHC card. While not a 32 GB or 64 GB card if you are in the market for a 16 GB card this is a deal.

Deal ends November 13.
[Android General] quattro527:
I had ordered one of these a month ago. It was advertised at a Class 4. However, the actual card came was a Class 6. SanDisk has repackaged many of their Class 4 MicroSD cards (which theoretically run up-to-par as some Class 6 cards from other manufacturers). Don't be surprised if you receive a Class 6 instead. Good find!
[Android General] pisy3:
Hi thx
[Android General] baburaj1975:
thumbdata3

i record a video on my galaxy ace and miss to save it

i found one thumbdata3 file on my sd card suppose to be that mp4 file

can i open that file with any player

pls advice me
[Android General] NYLimited:
I am not a video / camera expert but I think the thumbdata3 files contain generated thumbnail database of pictures, found in DCIM folder mostly on the SD card of an Android phone. These files can be pretty large, but if you need you can freely delete them. If needed the app will recreate them again. The numbers behind the file extension are probably generated randomly depending on the device or something else. I am not aware of any specific software to view them with (other than Gallery) and I would guess that it does not contain the actual or full video you are missing. This is very limited information and I could be wrong but this is my understanding of the file.
[Android General] mustafah822000:
good

wow good work
[Android General] NYLimited:
Partitioning and formatting

The "PARTITIONING AND FORMATTING" section has now been moved from post 1 to

post 3

.

A very basic tutorial with illustrations is now also in post 3.

More later....
[Android General] irwanzac:
irwanzac

I have lenovo a789,can help me,,,how to inside recovery Menu in my device???
[Android General] NYLimited:
Sorry, I don't know your device or if it comes with recovery installed in it.

You may be able to find some good information on it

here

.
[Android General] xilen:
try CWM or rebooter app
[Android General] Nodali:
I think, this is will useful if we can apply it, but, how I can?
[Android General] NYLimited:
Not sure I can answer that question.

I don't know all the phones people use SD Cards in, all the operating systems and how they are all used. What I attempted to do here is offer some general information on cards (posts 1, 2 and 3) which should help most people understand their cards a little better. For example, people commonly think that a Class 10 card is always faster than a Class 4 card but this is may or may not be true. There are many things which impact a card's speed.

Was there something specific you wanted to know?
[Android General] Szczepanik:
w95 FAT32 and w95 FAT32 (LBA)

ny_limited

Wondered if you wanted to add anything about the different FAT32 mentioned in this xda HD2 post. It may be a clue as to why some people have slow SD card compared with others?

The most I could find was in the following old Linux post

Do you have any more info that you could share?

Cheers

Tom