WD My Book Live Duo - sector and I/O sizes changed after upgrade

[da1k1]

I upgraded Openwrt from 23.05 to 24.10 via sysupgrade(ext4) file. Upgrade went smooth, system boots and all partitions and data looks good but after checking fdisk -l /dev/sda I noticed taht sector and I/O sizes has changed.

It was:
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

It is:
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Should I be worried about it? How to check data consist?

[eduperez]

Looks like OpenWrt is now detecting the real physical sector size (many devices "lie" about it), and has decided to optimize the IO operations to match that size; I do not think there is anything to worry about here.

[da1k1]

By the way do you know why there is also sysupgrade (squashfs)? I assume that ext4 is what everybody should use.

[efahl]

@da1k1

I assume that ext4 is what everybody should use.

Squashfs is preferred for (at least) two reasons:

1. The on-disk image is smaller, so support for older disk limited devices is maintained longer.

2. You can do a firstboot recovery with squashfs, whereas with ext4, there's no RO partition from which you can recreate the initial install.

The latter also allows some traceability, with ext4 there is no way to know if some code or data ever existed on the device if it gets deleted (be it intentional or malicious).