Advice about microSD card

    • I recently bought a bunch of SanDisk Extreme Ultra A2 64GB for use in my HC2 and RPi4.

      A2 C10 V30 UHS-I U3
      SDSQXA2-064G-GN6MA

      I would recommend at least 16 GB and A1. A1 and A2 means that random access is good. Cameras typically access sequentially. Phones, tablets and SBCs random.

      When I bought from Amazon.de the price of the 64 GB cards was OK, so I got them. Slight overkill, probably. Previously I bought SanDisk Ultra 32 GB A1.

      Over provision is good. SD cards use wear leveling. So even if you only have 7-8GB in use, writes are rotated to all memory cells. So a big card can be expected to last longer.

      But then again, OMV, by default, write very little to the SD card.

      Buy from a reputable source. There are many fake SanDisk cards for sale.
      OMV 4: 9 x Odroid HC2 + 1 x Odroid HC1 + 1 x Raspberry Pi 4
    • Adoby wrote:

      I recently bought a bunch of SanDisk Extreme Ultra A2 64GB for use in my HC2 and RPi4.

      A2 C10 V30 UHS-I U3
      SDSQXA2-064G-GN6MA

      I would recommend at least 16 GB and A1. A1 and A2 means that random access is good. Cameras typically access sequentially. Phones, tablets and SBCs random.

      When I bought from Amazon.de the price of the 64 GB cards was OK, so I got them. Slight overkill, probably. Previously I bought SanDisk Ultra 32 GB A1.

      Over provision is good. SD cards use wear leveling. So even if you only have 7-8GB in use, writes are rotated to all memory cells. So a big card can be expected to last longer.

      But then again, OMV, by default, write very little to the SD card.

      Buy from a reputable source. There are many fake SanDisk cards for sale.
      Thank you! Yes, found the SanDisk Extreme Ultra A2 64GB on Amazon.it at 20€. Sounds like a good price.
      Somewhere i read that OMV does not use all the storage of a microSD so big, so it creates a second partition on the microSD. How this works? I can safely use a 64GB card?

      Last thing, how can i check if a microSD is fake? Amazon is a reputable source?

      Thanks again!
    • Retired. I love to garden and mess with computers. The more I mess with both the less I know about either.
      OMV 4.1.27-1 on a pair of Odroid hc2's w/ 4TB WD Blue. Running Nextcloud, Plex, & Heimdall - and a Raspberry Pi 3 running Pi-hole.
      Testing OMV 5.0.14-1 beta on an Odroid H2, HP dx2400, and Nanopi M4.
    • OMV only use about 8GB. And of that 8GB most is free unused but available storage.

      You can still safely use a bigger card. I do, without problems. A bigger card might be considered a waste, but as I said above, you can see it as a form of over provision to improve wear leveling. I suspect it isn't strictly needed because OMV by default is very nice to SD cards. Writes very little to the root fs on the SD card, thanks to the flash memory plugin.

      However, one danger with big SD cards is the temptation to use the extra space for something. Something that writes a lot to the card. That can cause the card to fail prematurely.
      OMV 4: 9 x Odroid HC2 + 1 x Odroid HC1 + 1 x Raspberry Pi 4
    • Yes, A1 should definitely be good enough. I don't know if the HC2 card reader interface can take any advantage of the even faster random access A2 offer. But at least I assume the HC2 can't use the new A2 features for command queueing and caching. But also I assume that A2 does not hurt the HC2 performance.

      It seems that availability and price for 64GB A2 cards may be better than for 64GB A1 cards. At least on a cursory check on Amazon.de.

      So it may sometimes be cheaper to get an A2 than an A1... At least on Amazon.de.
      OMV 4: 9 x Odroid HC2 + 1 x Odroid HC1 + 1 x Raspberry Pi 4
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