Pro tip - Check your SD card

#1

I had my pi-hole go belly up today. I had built it on an 4gig sd card I had laying around.

Went and reformatted it using the SDFormatter tool on my mac.

Then followed the advice from here:
https://www.broes.nl/2012/08/verify-the-integrity-of-a-flash-sd-card-on-a-mac/

Here are my results:
MacbookAir$ f3write /Volumes/FREE/
F3 write 7.1
Copyright © 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

Free space: 3.67 GB
Creating file 1.h2w … 0.370.0.46% – 1.66 MB/s
OK!
Creating file 2.h2w … OK!
Creating file 3.h2w … OK!
Creating file 4.h2w … OK!
Free space: 0.00 Byte
Average writing speed: 4.97 MB/s
MacbookAir$ ls -al /Volumes/FREE
total 7695488
drwxrwxrwx@ 1 user staff 32768 Mar 23 19:34 .
drwxr-xr-x@ 7 root wheel 224 Mar 23 19:18 …
drwxrwxrwx 1 user staff 32768 Mar 23 19:18 .Spotlight-V100
drwxrwxrwx 1 user staff 32768 Mar 23 19:18 .fseventsd
-rwxrwxrwx 1 user staff 1073741824 Mar 23 19:26 1.h2w
-rwxrwxrwx 1 user staff 1073741824 Mar 23 19:30 2.h2w
-rwxrwxrwx 1 user staff 1073741824 Mar 23 19:34 3.h2w
-rwxrwxrwx 1 user staff 718766080 Mar 23 19:36 4.h2w
MacBook Air$ f3read /Volumes/FREE/
F3 read 7.1
Copyright © 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.

              SECTORS      ok/corrupted/changed/overwritten

Validating file 1.h2w … 2096864/ 288/ 0/ 0
Validating file 2.h2w … 2096608/ 544/ 0/ 0
Validating file 3.h2w … 2090272/ 6880/ 0/ 0
Validating file 4.h2w … 1401456/ 2384/ 0/ 0

Data OK: 3.66 GB (7685200 sectors)
Data LOST: 4.93 MB (10096 sectors)
Corrupted: 4.93 MB (10096 sectors)
Slightly changed: 0.00 Byte (0 sectors)
Overwritten: 0.00 Byte (0 sectors)
Average reading speed: 17.08 MB/s

Should have checked it before using it…

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#2

Had a few SD cards died on me. Now I go with usb stick.
Corsair 16GB Voyager V2 16GB USB 3.0

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#3

The technology/quality in the USB sticks isn’t different than the uSD cards. Just a different form factor.

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#4

SATA and M.2 SSDs are available on ebay starting at about $5.00 each, add a USB converter for a few more bucks and have reliable storage.

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