daargles wrote:
> Biggles wrote:
>
>> We have two Moto G5 phones, both with 64GB micro SD cards for additional
>> storage, formatted to store files (i.e. so that the cards can be read in
>> a PC or another device. Several times now, on both phones, on starting
>> the phone from OFF, Android reports the SD card as corrupt and says "tap
>> to fix". Well the "fix" is to reformat the card, so hardly a fix.
>> Anyhow, the "corrupt" cards read OK in Windows 10 on laptop, and copying
>> the data in Windows then reformatting the card in Android seems to fix
>> the problem, then a couple of restarts later the card is reported again
>> as "corrupt". In frustration I have tried switching the phone off and on
>> again, and this usually clears the error, not always on the first power
>> cycle, but usually by the third.
>>
>> We don't tend to switch our phones off very often, but it is very
>> irritating to have to power cycle the phone several times to get the
>> card recognised. Has anyone else had this problem - I'm trying to figure
>> out whether it is Moto hardware, Android software, SD card or a
>> combination which is causing the problem. We are using two SD cards from
>> the same manufacturer, and I have tried one from a different
>> manufacturer which "seems" to not suffer from the same issue, but as it
>> is intermittent it's difficult to be sure.
>>
>> Never had a problem with my previous phone which was Android 5 but only
>> 16GB SD card.
>>
>> Has anyone else had this problem with SD cards in phones?
>
> It's an Android 7.0 problem. The issue is being widely reported in
> the Lenovo and Samsung communities, and it's always after a
> power-down restart that the issue occurs. With the Moto G5 series of
> phones, it's not so obvious that it's an Android 7.0 fault, but it's
> clear in the Samsung community - phone/SD card combinations work fine
> until they upgrade from the starting Android 6 to Android 7.
>
> Hopefully, the Android developer community will acknowledge the issue
> soon and fix it - after all, it shouldn't be too hard to find by
> tracking back through the code commits and finding any that relate to
> power-down procedures. It will be a change that was made between the
> final Android 6 and Android 7.0.
When you meld or adopt the SD card with internal storage, the SD card
gets encrypted. If you configure the SD card as secondary storage, you
don't have to encrypt it (which keeps it portable). Also, adopting the
SD card doesn't give you oldstorage+newstorage for capacity. You lose
the internal storage which got supplanted when you made the SD card all
of your internal storage capacity. Adoptable Storage is a bad idea.
Do NOT elect formatting the SD card as internal (primary) storage. This
adoption option became available back in Android 6.
https://liliputing.com/2015/10/android-6-0-can-treat-sd-cards-as-internal-storage-at-a-cost.html
https://www.androidcentral.com/adoptable-storage
There is no guarantee the certificate used in one version of Android
will the same one used in another version of Android. I'm not sure that
even different instances of the same Android version will use the same
encryption certificate. The encryption is performed on the SD card
under the instance of the Android version that did the encrypting. When
you choose to adopt the SD card to supplant internal storage, the SD
card *will* get encrypted. You don't get a choice. Once you elect
adoptable storage for the SD card, the SD is *never* to get removed;
else, it become unreadable (that's the point of the encryption). The SD
card gets locked to *that* Android instance.
According the 2nd article above (which Moto G5), Samsung removed
Adoptable Storage in their modified version of Android. Guess Moto
decided to let it slide through.
When I first saw Adoptable Storage, yeah, it looked like a keen way to
increase the interal storage. However, then I read further and realized
I was tossing my onboard internal storage for the far slower SD card's
storage. Instead of buying a cheaper smartphone with less internal
storage, and because Adoptable Storage wasn't anything I wanted to use,
I got a smartphone with more internal storage to start with. The SD
card - removed from my old smartphone and transferred to the new one -
remained secondary (normal) storage.
Users forget or don't know that flash memory cards are disposable memory
devices. They degrade with every write. Storing videos, audio, photos,
or other static data files incurs sufficiently low write volume that a
flash card will last a long time, like 10 years, or more. However, when
flash gets used in a scenario that generates a huge volume of writes
then its lifespan gets shortened at a much faster pace. Using flash as
internal storage used by the OS and apps means a lot of contant writing.
If you use the SD card for adoptable storage, make sure to get a fast
one, not the cheapies found in sales to lure you to a site.