Is f3 good to tell if an sd card is working correctly ?

[hary66]

Hi.

I've checked an SD card with f3write/f3read. Despite the result was no error at all, when I successfully flashed it with Raspbian, it turns to be wrong when the filesystem gets resized at first boot of my Pi !

So I wonder if f3 is able to tell me if my sd card is in good shape ?

[unfa]

Could you give more details about what went wrong?

[hary66]

I wasn't very explicative, but as you can guess, I'm playing with Raspberry Pi's. So I have some micro SD card that don't work properly (I only use these card for my Raspberry pi's).

For 1 of them, At first boot time after falshing a brand new Raspbian using "Balena Etcher", the filesystem needs to resize itself. So at that momment, strange things happens, it takes a long time, it shows some strange messages I can remember. Now that I'm trying again to start the pi again, it seems to start then goes to a black screen.

I must say these card has been previously used on a pi that was shutting down not properly (the power supply was going off, then back on in an unpredictive way, ) Balena Etcher sometimes fail, so I need to reflash that specific card. and at the end when it succeed, problems occurs when booting the pi. I remember sometimes, it could succeed for first boot, then crashing when doing first update.

Actually it seems that the card has some writting/reading errors, but at the same time, f3 is always 100% success.

So I wondr if f3 is a good way to tell an SD CARD is good or bad ?

I hope this help. (I have 3 micro SD having same strange behavior. One of them wasn't accessible from my machine (was at /dev/sdb but couldn't mount it). I format it in my camera and seems to work fine in the camera.....then it automatically mounted on my computer and I could see the photos and movies on it !

[AltraMayor]

Hi @hary66,

Yes, F3 can tell me if SD cards are in good shape.

How are you flashing Raspberry pi on the card? Please post the command. What's the size of the Raspberry file you are using to flash the card?

I'm not familiar with Raspberry pi, could you describe what you mean by resizing the file system after the first boot? How is it done?

Can you run f3probe on your SD cards and post the output on this thread?

It seems that you are testing these cards with a partition that only covers good blocks, and using another partition size or another partition while flashing Raspberry pi on the card and booting it up. In other words, you may be testing only part of the drive with F3 and later using beyond what was tested.

[hary66]

Hi and thanks to take the time for helping.

I use Balena Etcher to flash the OS on the card. I also had the same problem trying with dd, so it doesn't seem to be related the way I do the flashing.

By "resizing the filesystem", I mean, when you boot the first time a raspberry pi on a brand new SD card, it resize the file system to use the entire space of the card. I far from being specialist, buut when you flash the card, it will use only the minimum space it needs to flash (I think minimum is 4GB), so, if you use a 32GB card it wil resize the file system to use the entire 32GB of the card. I must say that the crsh sometime occurs later or at a different stage like when I update the OS. It seems there are some writting errors on the card.

Here is the result of f3probe: :/dev$ sudo f3probe --destructive --reset-type=2 /dev/mmcblk0 F3 probe 7.0 Copyright (C) 2010 Digirati Internet LTDA. This is free software; see the source for copying conditions.

WARNING: Probing normally takes from a few seconds to 15 minutes, but it can take longer. Please be patient.

Good news: The device `/dev/mmcblk0' is the real thing

Device geometry: Usable size: 14.64 GB (30703616 blocks) Announced size: 14.64 GB (30703616 blocks) Module: 16.00 GB (2^34 Bytes) Approximate cache size: 0.00 Byte (0 blocks), need-reset=no Physical block size: 512.00 Byte (2^9 Bytes)

Probe time: 3'07"

[AltraMayor]

Thanks for the f3probe output. According to the f3probe output, the card is generally working.

When you tested this card with f3write/f3read, did you save the outputs? If so, could you post them here? Did you run f3write/f3read on the Raspberry pi or on your computer? I've come across machines that for a reason or another would have problems with any good card. Can you test the card on another Raspberry pi board?

Are you able to cool the drive during use? Drives, in general, are sensitive to temperature. Even a good drive may fail while hot during use.

[hary66]

I ran f3write/read but didn't keep the output; but it didn't show anything wrong from my understanding.

Actually, I have 3 card with same problem, and these card have been tried on different pi board (at least 3) plus all these pi board are working good with other sd card.

No, I'm not really able to cool the card when in use. (do you mean with some kind of cooling spary ?)

Where are you from ?

[hary66]

Can't I get any more help ? Despite having problem with SD card, I never had f3 complaining about something. I wonder if I'm using it right.

[AltraMayor]

@hary66, combining the output of f3probe you posted and your statement that f3write/f3read couldn't find any error, your card is working. But I don't know what's going wrong with your setup.

About cooling the cards while using them, you can be creative. For example, putting a small fan next to the card, placing an ice pack over the card, etc. Even keeping an eye on the temperature with a thermometer might give some insight.

You can find where I'm from on my profile: Boston, MA. But I don't really see how this helps this issue in any way.

On whether you are using F3 right, this is a tricky question since you haven't bothered to repeat the test and post the output here. I'm putting my time forward to help others, but you have to investigate the problem yourself.

[hary66]

I was asking where 're you from beacause your name sound lie French and I was wondering if I could easily send the suspicious SD card for expertise. Sorry if I've been behaving bad. I'll try to re-do a f3write/read again and send the output.

[hary66]

Here is the result of f3write/read. As yo can see, no errors !

harold@harold-ThinkPad-T530:/media/harold$ f3write disk/ F3 write 7.0 Copyright (C) 2010 Digirati Internet LTDA. This is free software; see the source for copying conditions.

Free space: 14.57 GB Creating file 1.h2w ... OK!
Creating file 2.h2w ... OK!
Creating file 3.h2w ... OK!
Creating file 4.h2w ... OK!
Creating file 5.h2w ... OK!
Creating file 6.h2w ... OK!
Creating file 7.h2w ... OK!
Creating file 8.h2w ... OK!
Creating file 9.h2w ... OK!
Creating file 10.h2w ... OK!
Creating file 11.h2w ... OK!
Creating file 12.h2w ... OK!
Creating file 13.h2w ... OK!
Creating file 14.h2w ... OK!
Creating file 15.h2w ... OK!
Free space: 0.00 Byte Average writing speed: 8.10 MB/s harold@harold-ThinkPad-T530:/media/harold$ f3read disk/ F3 read 7.0 Copyright (C) 2010 Digirati Internet LTDA. This is free software; see the source for copying conditions.

              SECTORS      ok/corrupted/changed/overwritten

Validating file 1.h2w ... 2097152/ 0/ 0/ 0 Validating file 2.h2w ... 2097152/ 0/ 0/ 0 Validating file 3.h2w ... 2097152/ 0/ 0/ 0 Validating file 4.h2w ... 2097152/ 0/ 0/ 0 Validating file 5.h2w ... 2097152/ 0/ 0/ 0 Validating file 6.h2w ... 2097152/ 0/ 0/ 0 Validating file 7.h2w ... 2097152/ 0/ 0/ 0 Validating file 8.h2w ... 2097152/ 0/ 0/ 0 Validating file 9.h2w ... 2097152/ 0/ 0/ 0 Validating file 10.h2w ... 2097152/ 0/ 0/ 0 Validating file 11.h2w ... 2097152/ 0/ 0/ 0 Validating file 12.h2w ... 2097152/ 0/ 0/ 0 Validating file 13.h2w ... 2097152/ 0/ 0/ 0 Validating file 14.h2w ... 2097152/ 0/ 0/ 0 Validating file 15.h2w ... 1186304/ 0/ 0/ 0

Data OK: 14.57 GB (30546432 sectors) Data LOST: 0.00 Byte (0 sectors) Corrupted: 0.00 Byte (0 sectors) Slightly changed: 0.00 Byte (0 sectors) Overwritten: 0.00 Byte (0 sectors) Average reading speed: 19.33 MB/s

[AltraMayor]

Hi @hary66,

That card is fine. My hypotheses for the possible source of the problems you are facing are (1) a heat issue as I have mentioned in my previous comments, and (2) an issue while Raspberry Pi resizes the file system after the first boot. If you do have a heat issue, you are out of luck. In this case, all you can do is to allocate these cards to applications in which they are not overheated. You can test the second hypothesis flashing a boot that doesn't resize the filesystem; I don't know Raspberry Pi to suggest a solution here.

Please notice that my hypotheses do not exhaust all possibilities. But coming up with more hypotheses requires the identification of more clues.

[SampsonF]

Any chance bad areas are only in the reserved sectors of the file system such that f3write/f3read cannot test?

[hary66]

I think I've solve my SDcard problem/failure. I was using them on Raspberry pi and since I've replaced the power supply and buy a new card, it's been working ok for some time now. I've in fact soldered some wire directly on the raspberry pi avoiding using USBc or mini usb connector to power it. But it still seems that it blown up at least 3 or 4 cards. Some of them are still half usable but very unsafe with unpredictable failure, often when resizing the file system after the first boot, but not always. It might also fail on an update/upgrade... Hope this help.