How often should you format micro SD card

[brett8883]

Ever accidentally deleted a file? I have. In some cases it can be recovered with software. But format it....not at all. Nothing is recoverable. I accidentally deleted my SD once and recovered most of the files. I probably could have got them all back if I restored them to a different drive instead of back onto the SD card. Just sayin...once it's formatted, there is NO chance of recovery. If I format in the bird,I also get the message from windows, every time I plug in to transfer to my HD, that there is an issue with the drive and do I want to run diagnostics. When I did, Windows suggests a format. Never do. Don't think my system approves of the way DJI formats. Never had a problem (other than my idiot self accidentally erasing it).
PS....my cards never come out of the drone.

As mentioned before nothing is ever actually “deleted” from a card it’s just written over. When you “delete” a file from the card all that’s happening is the space that file is taking up is marked in the FAT as being available to be written over. When you format the card the FAT is being cleared out completely. In both cases the actual data isn’t being removed, it’s only the table that is affected and file recovery software should be able to recover the data as long as it isn’t written over.

There is what is called a “low level format” which overwrites the data repeatedly until it’s not possible to recover the original data but that’s not what is happening when you format with the DJI app as far as I know.

 

[Tomk_]

Ever accidentally deleted a file? I have. In some cases it can be recovered with software. But format it....not at all. Nothing is recoverable. I accidentally deleted my SD once and recovered most of the files. I probably could have got them all back if I restored them to a different drive instead of back onto the SD card. Just sayin...once it's formatted, there is NO chance of recovery. If I format in the bird,I also get the message from windows, every time I plug in to transfer to my HD, that there is an issue with the drive and do I want to run diagnostics. When I did, Windows suggests a format. Never do. Don't think my system approves of the way DJI formats. Never had a problem (other than my idiot self accidentally erasing it).
PS....my cards never come out of the drone.

Not actually true. If you format in the drone, it is a "quick" format. On the SD cards, the data is not overwritten. The address to where it is found is just "forgotten". Until the block is overwritten, it is still there and recoverable. If you accidentally format your card, new data will be written to the least used blocks first (the controller works to even out the usage of the memory blocks and will still save to the next least used block even after a reformat). So if your card was half full, theoretically you could reformat and use the card until it was half full again before any of the blocks are overwritten.
At least on a Windows machine, you can "repair" the drive (card) and recover all of the data you just "erased" by executing the chkdsk X: /f/x/r command (where X is the drive letter of your card). The FAT will be restored and your data will be "found" again.
If you did a "full" reformat on your computer, the data is overwritten with 1's and/or 0's in an attempt to obscure the data. Chkdsk will probably not work to recover, but there are dozens of recovery programs, many free, that will have little trouble recovering your files.
If you do a milspec security erase, data is overwritten 5 to 10 times for a total "wipe" of the data. At this point, recovery is doubtful.

 

[brett8883]

FWIW, hard drives also use a file allocation table. And people never routinely format those drives.

On Windows hard drives are formatted to NTFS and on Mac it’s APFS so different animals all together that have better data management and recovery which makes them more reliable.

It’s true you can format an external drive to exFAT to make them cross compatible with both Windows and Mac but in doing so you give up using a more reliable format. Besides it’s not practical to format hard drives routinely. Instead best practice would be to back up the hard drives to a second or even third location instead. Some high end cameras even have redundant SD card slots for the same reason.

Its also not like hard drives don’t fail. It happens all the time and it’s one of those things where it’s not a problem until it is.

 

[Tomk_]

Magnetic memory vs solid state memory are two completely different animals. About the only thing they have in common is that they are memory. The term "format" really is a hold over from magnetic memory. They actually need to be formatted to use vs just having a system installed like on your card.

 

[offtheback]

As the title says......how often should you format the sd card? After every flight and upload to PC? When it gets full??? Thanks!

Most everything I've read says to format cards after download.Cards are different than hard drives in many ways.

 

[offtheback]

I'm saying the downside is it takes extra time to format. And if formatting doesn't make a noticeable difference, I'd prefer not to spend time doing it.

Also, I'm saying you should do whatever you want to do

I guess that depends on your download style.I remove card after a shoot,download to computer via card reader and format upon insertion into the aircraft.Formatting takes 2 seconds.

 

[Zbip57]

I just pull the card and stick it into my computer to copy the files to my computer. Then delete the no longer needed files from the card. There's no need whatsoever to reformat the card unless there's an actual issue that requires correcting.

A "quick format" doesn't delete anything, but merely clears the file index table so that the storage space is marked free of files and available for overwriting whatever was there as new files are recorded. A full format takes much longer as it will actually overwrite the entire storage space.

There are pros and cons to formatting, depending on what you're trying to achieve. The device using the card typically creates its own file folder system containing certain files, regardless of whether the card is inserted blank from being freshly formatted in a computer or is formatted within the actual drone/camera.

Generally it will create a DCIM folder under which is stored your photos and videos. The Mavic Mini (and probably all DJI drones) also create a "hidden" MISC folder under which there will be several more hidden folders holding various index and log files. One of those indexes stores the file numbering for your recorded photos and videos.

If you "quick format" your card, whether on your computer or in the drone, releasing all the file space as available to be overwritten, then the camera/drone will have lost count and will start freshly numbering your photos from zero again. Some people may want that, but I just find that a nuisance when I end up with a bunch of files having the same filename again.

I prefer to format new cards in my computer, rather than in the drone, because I like to add a txt file containing my contact info in case the drone or card ever gets lost. If the card is formatted in the drone, it requires an extra step to take the card out again or connect a USB cable to add the contact info file again.

 

[Meta4]

If you "quick format" your card, whether on your computer or in the drone, releasing all the file space as available to be overwritten, then the camera/drone will have lost count and will start freshly numbering your photos from zero again. Some people may want that, but I just find that a nuisance when I end up with a bunch of files having the same filename again.

Maybe that's a DJI Fly thing but under DJI Go 4 formatting the SD card makes no difference.
If you've selected the continuous option for File Index Mode, the file numbers don't reset to zero after formatting.

 

[Grandpa don]

I just use the Fly app to format new SD cards. Then instead of manually removing or deleting other videos one at a time, I'll just use the format feature to wipe the card clean and get it over with all at once. Otherwise it really is not necessary. But it doesn't hurt anything to do it often.

 

[Grandpa don]

I'm saying the downside is it takes extra time to format. And if formatting doesn't make a noticeable difference, I'd prefer not to spend time doing it.

Also, I'm saying you should do whatever you want to do

When I do use the format feature in the Fly app, it only take a few second to complete. Hardly any time at all.

 

[Tomk_]

My Mini 2 doesn't reset numbering by changing cards or reformatting.

 

[BuddyM]

He doesn't offer a great explanation as to why though. His reasoning is that "It keeps things cleaner on the card".

I've always been formatting my SD cards in my camera and in my drone after uploading to a hard drive instead of erasing old photos. Why? If anything happens when uploading photos to a hard drive the chances of recovering a partially damaged or corrupt SD card are much higher from a clean card, where there were previously no erased photos (that leave a lot of data on the card) on the SD Card.

 

[Zbip57]

Maybe that's a DJI Fly thing but under DJI Go 4 formatting the SD card makes no difference.
If you've selected the continuous option for File Index Mode, the file numbers don't reset to zero after formatting.

My Mini 2 doesn't reset numbering by changing cards or reformatting.

Well there I go again, shooting from the hip before checking whether the gun's even loaded. D'oh.

I remember seeing that File Index Mode option on the Phantom's app, but can't find anything similar in the Mini's Fly app.

I just checked my Mini and it's as you say. The file numbering system continues on from the same place even after formatting the card. It makes no difference whether it's formatted in the drone or in the computer.

Interesting though, it also doesn't matter whether the phone with the app is attached to the controller or not. I took the card out and formatted it in my computer. Then reinstalled the card in the Mini, powered it up, and powered up the controller without the phone attached. Then pushed the photo shutter button on the controller a couple of times. The file numbers on the photos incremented from where they left off before formatting the card.

Does it store the most recent number on the controller, or on the drone itself? The index number is clearly not saved on the formatted microSD card, or in the Fly App on my phone that wasn't even attached. Interesting.

 

[Tomk_]

I believe that the numbering comes from the drone rather than the app. I say that because it doesn't matter if I change cards or switch between my phone or a tablet... the sequential numbers march merrily on.

 

[rehkram]

FWIW, hard drives also use a file allocation table. And people never routinely format those drives.

Well there you go again with the generalizations. I and many others do. With major releases to the opsys I routinely do a clean install.

It's easier these days, what with the cloud model. There is a long checklist I store in my brain to avoid losing access to apps & data, etc

9 times out of 10 everything runs faster after blowing away the disk.

 

[rehkram]

The fact is, each brand + model of card is distinct and may vary from the original IEEE standard (or whatever standard governs SD cards) in exactly what it will do on receiving a given UI (user interface) management command. Also, whatever you think you're doing when running a high level UI command to 'move' files from card to computer is, in fact, executing multiple lower level commands serially, and not a doing a single 'move'.

For example, there is no such thing as a single instruction 'move' in mid-level computing, as such. What I mean by this is, in this application, 'move' is a UI call to 'copy to the computer' followed by an 'update to the FAT table on the card'. Each of these operations may involve multiple steps. If the string of commands is interrupted, and the card is not fault tolerant, hey presto, corruption.

In other words, you can't assume that what you think you're doing is what's actually being done. That's the best way I can explain it. KIS principal states, IMHO, reformat from the host device (camera/drone) before every shoot because fewer operations can possibly go wrong; you're just blowing away the index.

And yeah by the way I've trashed several SD cards in my cameras etc in the past, though admittedly not so much recently, which is a good thing.

So that's where I'm coming from, and y'all should just go ahead and do whatsoever you like!

 

[Jon]

Hmmm... My M2P has a 64 GB card. It’s got about 2,000 images in the Media 100 and 101 folders. And barely 2 GB used out of 64. A couple years ago I emptied it; maybe I’ll do that again in a couple more.

 

[Bill Kennedy]

Fascinating stuff - but what's the answer to the original question?

 

[Dougcjohn]

I use multiple 64 GB cards(10, V30 A2, each dated 1st use) in multiple crafts - Mini up through Inspire & Matrice. I pull the card after each session & replace with another card onsite. Transfer file sets to SSD HD (for on-site review), and place card back in credit card sized card holder at the end of the stack cycle. The SSD HD contents are later transferred to an 8 Drive NAS for archival storage & use with Processing Stations. Next card inserted into craft & formatted at current session end, so it’s always available fresh for next session. Each time a card is removed from stack, it’s formatted in drone.

Provides a fresh Card index for new session. If a week or so later, realize I need a fresh copy of older file set... the card is sitting in stack and available as an additional backup set. If not needed, it’ll eventually get reused in one of the crafts.

No harm formatting to clear indexes... rated MTBF on modern cards is so high, it’d most likely be replaced before an actual card failure. Provides additional temporary backups for minimal cost & risk management. Never had an issue, don’t expect will be either... if not due to self User Error, which is normally the highest probability of error for any storage media.

Even good quality, hi-speed cards are low cost. Practice of multiple cards isn’t costly and provides additional cards if there was a possible problem encountered in field. In addition, it separates a days project on multiple cards if craft goes down or creates a unforeseen problem.

Not one to keep all eggs in one basket, is my philosophy.
Everyone has there own routine... on DSLR or sUAV. Use of low level or full formatting would be reserved to securely destroy or correct a possible sector / media problem. Which is possible and not indicative as a failing card always.

Adapt a routine & practice that works for you, that will provide the best outcome for your usage. Changing that practice often will possibly result in a User Opps!

 

[Carll]

My hobby is photography, one of the main reasons for getting a drone.
For many years it has been best practice for regularly format your SD card, and ideally in the device in which it is being used.
It does no harm and cleans out any issues, as well as preventing fragmentation but did you know there is a difference between formatting a card whilst connected to a PC, and formatting in the device it is intended to be used in (there is a specific MS windows SD format program you can use if you are interested).
An SD card is just like any other modern storage device, if you have a more modern PC with an SSD drive, they have the same issue of eventually producing errors, the only problem here is you cannot format and start again. Mind you because they are more complex, they have built in error checking; why, because eventually they will have small failures, so portions of the solid state memory are marked as corrupt and cannot be used, even after a format, only a low level format would clean this off.