Installing OpenWRT on NanoPi R3S, is it now safe to commit flashing to eMMC, also SquashFS vs EXT4 dilemma

Installing and Using OpenWrt
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Few months ago it was suggested not to flash OpenWRT to EMMC, but to use it from the SD card instead. Something about bricking the NanoPi R3S. Now that v24 is out of beta, is this still the case? Is it now safe to flash latest v24 (24.10.1) to eMMC?

And also one more question: SquashFS or EXT4 image?
Given choice I would prefer SquashFS for easier reset to factory defaults (like if I mess something while experimenting and learning), and also to reduce the wear to the EMMC in long term.
But reading on the subject I found this below, and now I am confused should I use SquashFS or not:

https://github.com/ShareCat/openwrt_notes/blob/main/Ext4%20vs%20SquashFS.md

There is a generic problem when running SquashFS on NAND: The issue is that SquashFS has no bad block management at all and requires all blocks on order; but for proper NAND bad block management you also need to be able to skip bad blocks and occasionally relocate blocks (see squashfs and NAND flash).That's why raw SquashFS is a bad idea on NAND** (it works if you use a FTL like UBIFS).

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MMC is not raw mtd. (unlike older compactflash)
You can use any filesystem you want.

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Thanks for clarifying that. :+1:

edit: I suppose when using SquashFS, an additional partition is needed for stuff like Addblock for instance?

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Well, all of your config lives in the overlay partition, but stuff like adblock lists usually live in RAM (i.e., /tmp) and get recreated/downloaded every time you reboot (or refresh them).

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It is advisable to put massive in/out on USB or other external storage. Another data partition on remaining emmc can serve both ext4 and squash installations if sysupgrade goes bitter

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Thanks.

@efahl that sounds fine, keeping adblock lists and similar stuff on ramdisk. As there's 2GB of RAM and it is like ~99% free. So I just install packages, or better yet icorporate them in custom SquashFS image, and don't worry about app data?

@brada4 by "upgrade going bad" are you referring to having multiple SquashFS installations/partitions, and is that like possible? Or am I misunderstanding?
edit: By "massive in/out on external storage" you mean keeping app data and similar stuff somewhere external?

I am perusing the OpenWRT documentation, but is there some more concise "best practices" kind of list for planing partitions/storage/backup and similar stuff?

Also, did anybody flash the latest 24.10.1 OpenWRT to the internal eMMC? Is it safe to do so and replace the FriendlyWRT on NanoPi R3S?

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Either way is fine, you have lots of space on the device and if you use any of the ASU clients to do upgrades, the installed packages will migrate from overlay into the squashfs as a matter of course.

All the apps are written to store only their required "static-ish" config data into flash, transient data is always written in /tmp (i.e., RAM), so as to maximize the life of old, less-than-robust FLASH-based devices. So, yeah, just let them do whatever they do and don't worry about it...

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