Using an SD card to increase memory on Android 7 tablet

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I have an Insignia tablet which is running Android 7. The tablet has 1 GB of RAM. I have read that I can increase the memory by using a Micro SD card as additional memory. From what I understand, this will involve rooting the tablet, then editing one or more lower-level config files.

I am concerned that if I do this, I could brick the tablet. Also, leaving it rooted will leave it vulnerable to hacking, malicious software, etc.

Can anyone point me in the right direction on these issues? Currently the tablet is pretty much unusable because it is so slow. I feel it will run a lot faster if I can increase the memory. But I don’t want to live dangerously in this case, because this tablet will be for my daughter. Ideally, I would like to root the tablet, change the config to allow for using the Micro SD card for additional memory, then unroot it. Is that possible?

Group "L" (Linux Mint)
with Windows 10 running in a remote session on my file server

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MrJimPhelps wrote:

Can anyone point me in the right direction on these issues?

Try this tutorials for both rooting and without rooting :

https://www.alltechbuzz.net/increase-ram-android-phone-sd-card/

https://appuals.com/how-to-use-sd-card-as-extra-ram-in-android/

https://joyofandroid.com/increase-ram-in-android-phone/

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The articles you linked to are very clearly written and easy to understand.

I have already tried Roehsoft RAM-Expander, but it didn’t work. I will shortly try the other methods. And this afternoon I will purchase a good Micro SD card.

It will be really good if this works – my daughter needs a tablet of some sort for school, and we already own this tablet, but the lack of memory in the tablet makes it run really slow.

Group "L" (Linux Mint)
with Windows 10 running in a remote session on my file server

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That would only increase storage, not RAM. You might as well download more RAM for all the good it would do.

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wavy, TaskForce141, CADesertRat, Microfix

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Well, theoretically, it could be used as random access memory. But even the fastest SD is going to be several orders of magnitude slower than any purpose-made RAM chips and I don’t think any modern operating system supports this.

Heh, I understand back in the 1960s some people even used tape drives as random-access memory like that… as in, DECtape on a PDP-8?

BUT… this is what virtual memory was invented for.

MrJimPhelps wrote:

From what I understand, this will involve rooting the tablet, then editing one or more lower-level config files … … But I don’t want to live dangerously in this case, because this tablet will be for my daughter. Ideally, I would like to root the tablet, change the config to allow for using the Micro SD card for additional memory, then unroot it. Is that possible?

Well sure, Android has the Linux kernel, and as root you typically could turn on swap if you really want to. It does expand the allocatable virtual memory, it’s just that Android often has a “light” memory management model and I/O scheduler, compared to mainline or PC-distro Linux. So you might not get graceful swap management, and then there’s the power management weirdness… such as low-power states for the card slot, which would mean losing swap, and the device vendor’s power manager may not be aware of the concept of swap on a mobile device so may just power it down without deallocating swap, AND swap may not be deallocatable if it’s in use…

(Yes, it’s really paging and not swapping anyway.)

Unrooting after making the appropriate changes to (partition tables,) fstab and boot sequence certainly should also be possible unless the vendor has been doing silly things with the bootloader. Oh and I’m not sure if all devices come with “mkswap” and “swapon” commands, worst case you might have to build parts from source… well the mkswap could be done on a Linux PC if you attach the SD card to it.

So enabling swap likely is possible, but doing that on a vendor-stock Android version very much does go under “living dangerously”. You’re probably better off rolling your own Android build from AOSP sources

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Using an SD card for “RAM” would be more analagous to a “SWAP FILE” to extend virtual memory, and would actually SLOW DOWN your tablet.   Even the fastest SD card would be many times slower than the internal memory of the tablet.

 

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Jim
a very tech place to look is
mn– ‘s advice of AOSP sources might be available there.

Just because you don't know where you are going doesn't mean any road will get you there.

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After reading some of the things above, I’m coming to the conclusion that all I need to do is “sudo” edit certain config files, just like in Linux, and specify the memory card as swap file space. So technically it won’t be what you might call “primary” memory, but rather “supplemental” memory.

My line of thought here is to get a USB cable with a standard plug on each end (I have one at my job), and connect the tablet to my Linux computer by connecting a USB port on each. This might allow me to treat the internal drive in the tablet as an external drive for my Linux computer. If that works, I should be able to “sudo” edit the correct config files to designate the memory card as swap file space. I’ll then unplug the USB cable and reboot the tablet.

I’ll put an update here after I have tried that.

Group "L" (Linux Mint)
with Windows 10 running in a remote session on my file server

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You’ll need at least “adb” (Android Debug Bridge – on modern versions of Ubuntu, android-tools-adb in the universe repository); and probably also “fastboot” on the PC end and turn on “debugging” on the tablet, to be able to run a shell on the tablet that way. (It’s in the developer options part of the settings, so you may need to unhide developer options first.)

Then, “adb devices” should find your device, and “adb shell” would give you the shell. At user level.

And from there… you’ll most likely find that there’s no “sudo” or “su” available. I mean, getting a root shell is exactly what people mean by “rooting” the device, and that’s a few steps more complicated than getting a normal user-level shell.

The “supported” method (FSVO) to get a root shell is to (re)flash the device with a package that includes it, or at least is flagged as a developer or testing build instead of production. (After that, you can go “adb root” from the PC and…)

The reflashed part may be the recovery mode boot image, which is separate from the regular system and is used normally when installing system-level updates, but stock versions may not include externally accessible shell or passthrough block device access.

Most of the other methods involve running a known exploit to drop a setuid binary somewhere in the device’s internal storage that it can be run from. Those being what they are, if the device has gotten a system update from the manufacturer since the exploit became public, well…

Reflashing is what you use fastboot for. (No, I don’t know why it’s called that.) Samsung devices usually need a different tool. Also may or may not need to enable the reflashing functionality on the device, which usually wipes it to factory state and may also void warranty. For some devices you need to get an unlock code from the manufacturer.

Custom recovery can get you pretty far already.

Modern Android’s default user-level shell is a bit more restricted than what people are used to from regular Ubuntu or other “friendly” Linux distribution. It’s typical to not be able to get dmesg output directly, for example.

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MrJimPhelps

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The cable should work with windows and likely Linux. I am interested so keep us up dated.

Just because you don't know where you are going doesn't mean any road will get you there.

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