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SD Card Diagnosis

Posted: Sat Feb 23, 2019 7:17 pm
by Shep
I frequently liken the Duet and even Raspberry Pis to dash cams due to the way they handle microSD cards. They can fail, and when do, it's weird failure types. There's a good card testing tool on the Street Guardian Support page -- Software --> Memory Test Software. Here is a [direct link] to the software too, but the first link is in case the second no longer works.

This will confirm every sector on the microSD card is readable. This can take a while for larger cards, but luckily for the Maestro anything over 8 GB is usually not needed anyhow.

Re: SD Card Diagnosis

Posted: Sun Feb 24, 2019 11:51 am
by TheBum
For the Mac, the best (cheapest) option I found is Disk Drill. A free license is available for personal use, which will allow you to do a block-level scan (called "Deep Scan" in the software) and even recover deleted files (assuming the blocks haven't been overwritten). Unreadable blocks will be marked as bad with a hidden file in the file system.

https://www.cleverfiles.com/

To get to the Deep Scan, hover over the right side of the SD card's entry in the main window. A gear icon will appear, which is a menu of operations to perform on that drive.

Re: SD Card Diagnosis

Posted: Sun Feb 24, 2019 2:47 pm
by Shep
Don't know if this applies, but there is apparently an alternative called TestDisk that is available for Mac and is open source? Quite popular too.

https://alternativeto.net/software/disk ... atform=mac

Personally I love AlternativeTo.net, it has let me find so much software I would have otherwise never known existed! Might help, might not, worth mentioning though!

Re: SD Card Diagnosis

Posted: Mon Feb 25, 2019 12:08 pm
by TheBum
TestDisk doesn't appear to be able to map out bad blocks. Granted, if you have bad blocks, chances are you'll get more in short order and you're probably better off replacing the card, but in a pinch...