Manfred Hollstein composed on 2024-10-28 16:03 (UTC+0100):
On Mon, 28 Oct 2024, 15:18:46 +0100, Carlos E. R. wrote:
Still no explanation on how those cryptic options do the conversion from ext3 to ext4.
ext3 basically introduced has_journal over ext2, while ext4 added the feature extent amongst other stuff. Adding the "extents" feature will turn an ext3 filesystem into an ext4 one. The "uninit_bg" feature only deals with how long the lazy_itable_init will take and should only have an effect on creating a new filesystem. "dir_index" is not even named in "man mkfs.ext4", so, I guess, it goes back to ext2 or ext3.
BUT, all this does not answer why the listed command should solve the year 2038 problem at all! The most relevant element for this is the inode size, which should be 256. Here is what "man tune2fs" says:
-I Change the inode size used by the file system. This requires rewriting the in‐ ode table, so it requires that the file system is checked for consistency first using e2fsck(8). This operation can also take a while and the file system can be corrupted and data lost if it is interrupted while in the middle of convert‐ ing the file system. Backing up the file system before changing inode size is recommended.
File systems with an inode size of 128 bytes do not support timestamps beyond January 19, 2038. Inodes which are 256 bytes or larger will support extended timestamps, project id's, and the ability to store some extended attributes in the inode table for improved performance.
So, Felix is probably on a good way to assume, "ext4" will help him solving the 2038 issue, but the increase of the inode size is missing!
Carlos' <https://linuxtiwary.com/2016/02/04/how-to-convert-ext3-file-system-to-ext4-without-any-data-loss/> makes no mention of the inode size issue. Until reading your quote, it was not obvious to me that changing of inode size was supported for an existing filesystem. I have a lot of tune2fs -L and -I runs in my future as long as I wish to continue as much as possible to keep my extensive OS archive to some extent "functional". :p -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata