This is the question you have asked us the most, so we are going to answer it.
MicroSD cards have a bad reputation for long-term storage of information, this comes from old cards that had a low write limit and low-end cards that are very cheap but have high failure rates, there are only We do have to review the comments on the sales websites for these cards, but current and quality cards are valid for storing long-term information.
In the case of BCubium the card that comes is high-end, we only use two
These cards that cost between 4 and 5 times more than the low-end ones and have very good references by consumers.
Both Samsung and Lexar give a 10-year warranty on these cards.
These microSD are normally used in video and still cameras where the writing volume is very high and they respond very well.
In our case, the operating system is in the eMMC memory of the NanoPI Neo Plus 2 motherboard and the MicroSD card is used to store the Blockchain and it is already preloaded from our laboratory, so the read and write ratios are due to the operation. derived from the writing of the blocks every 10 minutes (approx.), the indexing of the transactions and the communication between the different full nodes of the network. This functionality involves an average number of card reads and a very low number of writes, which means that the card suffers very little because what most affects microSD is the writing of information.
Choosing a day at random the average rate of io per second is 742 kB of reading and only 53 kB of writing.
We can also see it at the moment by running the dstat tool, obtaining similar values:
So, making the full node functionality of Bitcoin plus a Lightning Network Daemon as it is done in BCubium, we have an average ratio of reads and very low write range microSD cards alta are a fully valid device for safe storage in the short, medium and long term. Commenting that the personal information of the node is not stored in the microSD, only the Blockchain is stored, so if it were damaged, another card could be inserted and the history of Bitcoin could be resynchronized.