Let me start out by giving you some general background information. My actual question is at the very bottom of this post. ---------- # Background, part 1: Journal replays vs. consistency checks. Please assume that your Android device uses the ext4 filesystem for its internal storage, and the FAT32 filesystem for its removable MicroSD storage (if present). On ext4, a "journal replay" is a partial filesystem check-and-repair operation which normally takes no more than few seconds. ([Source](https://unix.stackexchange.com/questions/353671/what-does-e2fsck-do-during-bootup).) The Android kernel does a journal replay whenever necessary. (Based on [this source](http://confluence.wartungsfenster.de/display/Adminspace/Mount+ext4+without+journal+replay) and [this source](https://bugs.launchpad.net/ubuntu/+source/partman-basicfilesystems/+bug/41624/comments/6).) On ext4, a full filesystem consistency check takes longer. For an average Android device, it takes 12 seconds or so. (Based on [this source](https://github.com/android/platform_system_core/commit/07068de7894d3b8c4faf6c6c0844e1ec9684c5b1).) FAT32 is a non-journaling filesystem. So there are no journal replays. There are only consistency checks. ---------- # Background, part 2: It's probably a good idea for your OS to do periodic consistency checks. Here's why. Microsoft program manager Kiran Bangalore [writes](https://docs.microsoft.com/en-us/archive/blogs/b8/redesigning-chkdsk-and-the-new-ntfs-health-model) that there are certain cases in which a filesystem can become corrupted. On a journaling filesystem such as ext4, such cases are exceedingly rare. On removable MicroSD cards, I suspect that such cases are not so rare. The usual way to check for such corruption is to configure your OS to run a consistency-check tool every so often. Such tools include chkdsk, ScanDisk, Apple Disk Utility, fsck, and others. Even on ext4 storage built into an Android device, periodic consistency checks are probably a good idea. The tune2fs manual page explains why: > Bad disk drives, cables, memory, and kernel bugs could all corrupt a filesystem without marking the filesystem dirty or in error. If you are using journaling on your filesystem, your filesystem will never be marked dirty, so it will not normally be checked. A filesystem error detected by the kernel [may] still force a [consistency check] on the next reboot, but it may already be too late to prevent data loss at that point. (Note that, on Android, I think a filesystem error detected by the kernel will _not_ lead to a consistency check on the next reboot. Android is strange that way.) ---------- # Background, part 3: Here's what other OSes do. ### Windows Windows Vista, and all later versions of Windows, include an [NTFS self-healing](https://technet.microsoft.com/en-us/library/cc771388(v=ws.10).aspx) feature. Kiran Bangalore therefore [writes](https://docs.microsoft.com/en-us/archive/blogs/b8/redesigning-chkdsk-and-the-new-ntfs-health-model) that, nowadays, Windows users no longer need to run periodic consistency checks anymore. He explains that the OS "will inform you when ... corruption is found". ### Windows 10 Mobile Windows 10 Mobile is probably the [third-most-popular smartphone OS](http://www.idc.com/prodserv/smartphone-os-market-share.jsp) . I think it uses NTFS. So perhaps it also can do NTFS self-healing. ### OS X Mac OS X runs fsck_hfs -p during [every boot](https://apple.stackexchange.com/questions/88604/how-to-auto-run-disk-repair-on-os-x-after-each-system-crash#88676) . I don't know what this does. See the [manual page](https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man8/fsck_hfs.8.html) . ### Linux It's true that [some](http://markmail.org/message/7rgbdczwvhxbsipa#query:+page:1+mid:tbkmrhpcgetlwmy4+state:results) ext4 developers say that periodic ext4 consistency checks aren't particularly useful. But [other](http://markmail.org/message/7rgbdczwvhxbsipa#query:+page:1+mid:ew5osoby3kaacf6f+state:results) ext4 developers say that these checks improve safety and reliability. In practice, when a filesystem is marked in error, Linux runs a consistency check at the next reboot. At other times, modern Linux distributions don't do automatic periodic consistency checks, ever. Those who want them must schedule these checks themselves. ### Android Stock Android includes an [ext4 consistency-check tool](https://android.googlesource.com/platform/external/e2fsprogs/+/master) . As well, it includes a consistency-check [tool](https://android.googlesource.com/platform/external/fsck_msdos/+/master) which works on removable MicroSD cards of 32 GB or less (but may corrupt larger cards). Finally, your device may or may not also include fsck.exfat or exfatfsck, for running consistency checks on removable MicroSD cards of 64 GB or more. But does the OS ever run any of these tools automatically? ### iOS The iOS filesystem is normally either HFSX or APFS, and fsck is [included](https://www.theiphonewiki.com/wiki//sbin) with the OS. I don't know whether or not iOS ever runs automatic consistency checks. ---------- # Here's my question. Please consider the stock ROMs shipped with current Android devices. Do such stock ROMs ever periodically run consistency checks, either on the internal storage device or (if applicable) on the removable MicroSD card? (P.S. In cases where a device shuts down gracefully and has enough battery charge left, it's [possible](https://serverfault.com/questions/483093/fsck-on-shutdown-instead-of-startup) to run a consistency check at shutdown instead of at startup. But it takes some engineering effort to implement such functionality, and so operating system developers normally don't bother. I wonder what Android does.) (P.P.S. I also wonder whether or not there exist _any_ smartphones, running _any_ OS, which do _any_ routine periodic consistency checking. Again, please post comments below.)

I own an Android device with a removable MicroSD card. The card uses either FAT32 or ExFAT technology. These are "non-journaling filesystem" technologies, so the data on the cards can become corrupted in certain cases. Perhaps I should run a consistency check (e.g. fsck / Chkdsk / ScanDisk) every so often. A) How often should I run a consistency check on my MicroSD card? B) Also, if my device sometimes freezes and I must power it off using the power button, must I run a consistency check every time?

I own an Android device with a removable MicroSD card. The card uses either FAT32 or ExFAT technology. These are "non-journaling filesystem" technologies, so the data on the cards can become corrupted in certain cases. Perhaps I should run a consistency check (e.g. fsck / Chkdsk / ScanDisk) every so often. How can I run a consistency check on my MicroSD card, without having to plug the card into a PC?

I have a rooted Lenovo A369i. I use LagFix (fstrim) to TRIM partitions. Previously it was working well with /data but after I encrypted my phone it doesn't. I decrypted my phone by formatting. But now in the app it shows /data partition having kernel or hardware issues. It's not hardware because before encryption it was working well.

Based on this cyanogenmod forum thread , I tried to address the delay in running applications and switching between applications on my Galaxy Nexus running cyanogenmod with Android 4.4.4 by running fstrim manually. root@maguro:/ # fstrim -v /data /data: 11649122304 bytes trimmed root@maguro:/ # fstrim -v /cache /cache: 436121600 bytes trimmed root@maguro:/ # fstrim -v /system /system: 80490496 bytes trimmed root@maguro:/ # exit This has largely fixed the delay issues. The delay to return to the home screen, for example, has reduced from about 4 seconds to less than 1 second. Based on this performance boost, I expect the delay was caused by the filesystem running inefficiently. Isn't the Android OS supposed to run fstrim on its own? When is this supposed to happen?

With 4.3 enabling the support for TRIM (though I read that it was present since the first JB). I was wondering if there is a way for me to force TRIM on my device? Is there an app that I can sideload and have it issue it? I have a rooted chinese Tablet running on 4.2.2 JellyBean release. Just to add, it's a PiPo M1 Max tablet.

I am not sure if this app works. Can someone please help me? My phone is new and in its warranty period so I can't root it yet. I tried this app but I am not sure if it actually did something. Unlike the other famous app on the PlayStore for fstrim, it doesn't require root access which is quite incredible.

My phone is new so I can't root it because I don't wanna void my warranty just yet and trimming my phone would also not make a significant difference. Since most other apps on the Play Store promise to run TRIM only with root access, I don't think it's possible for this app to do so without root but if it can that's the best thing I can get. Can someone please confirm if this app actually works? Link to the app: https://play.google.com/store/apps/details?id=com.lagfix.fstrimmer

If **Device maintenance** app is launched in Samsung S8, after pressing **Clean Now** button, storage cleanup briefly shows different apps, storage space of which is being cleaned: System cache OneNote TopBuzz Actual view visible for about 2 seconds: I know that the last one is not among installed apps (when checking by name) so it must be part of some other app, but how can I find out to which app it actually belongs? No antivirus which I tried so far reported this as the malware. But maybe there is some system analyzer which shows similar cache ownership like the above app, but with more details? (Or maybe there is another method how to find origin of that TopBuzz symptom.) The phone is not rooted.

Owing to a recent [Motley Fool report](https://www.fool.com/investing/2018/12/05/cheetah-mobiles-ad-fraud-allegations-just-got-even.aspx) of Google's actions pertaining to Cheetah Mobile apps, it occured to me that I would like to either uninstall or disable (in case uninstall fails), the apps related to this company, and other companies, if need be. Now exposed as employing questionable techniques on even one app, it is unlikely I would ever trust any installed app from that company. What easy technique to recognize a company's apps are on my device and uninstall them, even if their app names, or their developer names, or their company names are obscure?

I have a Moto E phone. I use it as a tablet to run apps, not as a phone, so I do not always need to leave it on. Is it more likely that the device will last longer if I shut it off whenever I am not using it? Or is it better for the hardware of a phone to leave it constantly on, in sleep mode? And is it better to leave it constantly charging, or to only charge it whenever the battery is below 100%?

I bought a 2nd generation Moto E phone. According to this page at GSMArena.com , this phone has a "Corning Gorilla Glass 3, oleophobic coating" screen. I have seen many on-line shops selling "tempered glass screen protectors", a layer of plastic one can buy to put over the screen. I found this useful with some older devices I had, where the screen could easily become dirty and scratched. I am mostly concerned about being able to easily clean away fingerprints and to avoid having scratches caused by fingernails or creating worn out areas of the screen, due to frequent use. Is such a screen protector at all useful on a Gorilla Glass screen?

Many custom recoveries, like TWRP, have an option to use compression when creating nandroid backups. By default, this option is typically disabled. Is it safe to use the compression option? Are the only downsides the time that must be spent to compress the nandroid and the possible need for temporary working space to perform the compression? Any other reasons why that option is typically disabled by default?

I use to try (install and remove) a huge lot of apps to choose the ones I will actually like. I am afraid uninstalled apps can leave some residuals behind and this can crap up the system in some time. How to make sure this won't happen?

There are similar questions here, but this one is about a phone that doesn't turn on. I can't reset to factory. What should I do? Change my Google password? What information will the technician have access to?

So, recently, I've got myself a few broken Nexus 5 phones to try to repair them. One of these, however, eludes my attempts to diagnose/fix the problem. A few minutes after i press the off button to turn the screen off, the phone ceases to react. Experimentally, I found out it was about two minutes. Before that limit, pressing the button again wakes the phone ok, everything works. After that time, the phone doesn't work anymore, and requires long button press to force restart. It doesn't happen if the phone is connected via usb to charger/pc, no freeze whatsoever, only hangs on battery. I've limited the scope of the problem to the mainboard - after transplanting it to different phone, same thing happens. OS version doesn't matter, tested on KK, Lollipop, and Marshmallow, original ROM's - all the same. Once when I connected frozen phone to PC, I entered a "DBI Apps Watchdog Reset! DemiGod Crash Handler" screen. (Not reliably reproducible behavior) Anybody has any idea what's going on and how to fix it? I have some experience with SMD soldering, so if it's something purely hardware related, I can attempt a fix myself. I also have a donor mainboard.

Have an unrooted tablet, a Samsung Galaxy Tab 10.2. Memory is getting tight on the tablet itself and my card is 64GB with most still available. I saw the answer using logcat built-in utility to delete log files and such. I would rather do it myself due to having routines that have done what they weren't supposed to do. I like having full control over what happens, let's just say I'm an old DOS fan who likes to do the nitty-gritty.

I've seen a few apps online, but they don't seem legitimate. From what I've seen, they don't seem to show what's going on while the drive is being defragmented. So I decided I wanna stay away from defragmenters in the Google Play store. What would be an efficient way to defrag my both my phone's SD card and internal storage?

What I mean by this. Is it expected that overtime, the performance of a device will be reduced, and the software will work slower? This is assuming no changes in core OS (e.g upgrade from 4 to 5 etc). For example, does installing and removing apps leave traces behind, that over time build up and slow the OS? Is there any indication that a user can look for, in order to determine if its time to flash the device, and re-install the OS? p.s Lets ignore the scenario where a bunch user installed process-hog- background apps are killing the device.

I installed CM10 on my GS2, and during the process I didn't format the file system as I wanted to retain my photos and music on the device. I was aware of an app called "SD Maid" that is *supposed* to be able to be able to clean up all these old app folders, but it doesn't seem to work. Does anyone know how I can clean up all these folders, or does a person have to just go in and manually delete all of them? (For an app to do this, the OS would have to have some sort of a referencing system of known installed files & folders, don't know if it has such a thing though.)