Good (Safe) Software to Format Large SD Card to FAT32

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jerryyyyy

Member
Jun 1, 2024
15
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I have a new security camera that needs a micro SD card formatted in FAT32 (not exFat) to work and I have a new 256GB card that windows will not format. I have tried all the windows software including diskpart. This is a known issue that seems to encourage a lot of people to write software of questionable origins.... do you all have any suggestions.... will cross post with Dan who helped me with a SpinRite issues, but this is not SpinRite... just looking for reliable advice.
 
The Windows 32GB FAT32 size restriction is artificial and imposed only by the Windows format utility. It is not a technical limitation. IMHE, most any decent partition manager (Mini-Tool Partition Wizard, Aomei Partition Assistant, Easus Partition Manager, et al) will create and format the SD card to its full size with ease.
 
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It is not a technical limitation
Of course you're technically correct, but there is an impact that Windows was avoiding. There are a maximum number of entries in the FAT32 metadata structure for tracking things, so the disk's sectors need to be organized into clusters to be tracked by FAT32. The bigger the disk, the bigger the clusters get, and a file with a single byte will still use an entire cluster of space. Windows was trying to avoid as much of this wasted space (known as slack space) as possible.
 
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[made a mistake with two threads, but will just write here].

I resized the partition to 30GB and the powershell formatted it and the camera used it. The camera does its own format on top of the FAT32. It is working... but I have wasted 226 GB! Food for thought.

The third party software set off alarms in VirusTotal and my University Crowdstrike Falcon so put them aside for a bit. I know about false positives but do not need trouble.
 
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Just some follow-up here. The card purchased from Reolink worked fine with no issues. It has exactly the same parameters stamped on it as the Amazon card. Anyway, the camera also works fine. Not sure what the issue was as I could format the Amazon card to 30GB... appreciate the help.
 
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Try adding an extended partition, and format the rest of it anyway. Likely the camera will totally ignore it, but at least when you copy to your computer you can copy to that second partition as well, or have a second copy of the photos for temporary use.
 
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