Reason for using ext2 instead of ext4 for portable drive backups?

[forbytten]

Hi,

It seems the filesystem for the portable drive backups was ext4 in 1c16d96, Apr 2016 but changed to ext2 in bf05e0e, May 2019. What was the reason for this and is it still valid in late 2024?

Search for changes containing "mkfs.ext4":

$ git log -S"mkfs.ext4"
commit bf05e0e7c44ada89bc906dca539ba064449eaf41
Author: drduh <[email protected]>
Date:   Sat May 18 17:47:13 2019 -0700

    Better backup and testing instructions

commit 1c16d968e9e1174204071d80fcf161029a022ae2
Author: drduh <[email protected]>
Date:   Mon Apr 25 17:49:51 2016 +0000

    Add encrypted USB backup instructions, grammar fixes

The initial change used ext4:

$ git show 1c16d968e9e1174204071d80fcf161029a022ae2|grep -A5 ext4
+    $ sudo mkfs.ext4 /dev/mapper/encrypted-usb -L encrypted-usb
+    mke2fs 1.42.12 (29-Aug-2014)
+    Creating filesystem with 7871744 4k blocks and 1970416 inodes
+    Superblock backups stored on blocks:
+            32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
+            4096000

The later change replaced ext4 with ext2:

$ git show bf05e0e7c44ada89bc906dca539ba064449eaf41|grep -A5 ext4
-$ sudo mkfs.ext4 /dev/mapper/usb -L usb
-mke2fs 1.43.4 (31-Jan-2017)
-Creating filesystem with 7871744 4k blocks and 1970416 inodes
+$ sudo mkfs.ext2 /dev/mapper/usb -L usb
+Creating filesystem with 10240 1k blocks and 2560 inodes
 Superblock backups stored on blocks:

[drduh]

iirc ext2 is compatible on both Linux and OpenBSD.

We might want to reconsider the backup strategy entirely in #446