EXT4 Changes Land For Linux 5.9 With Block Allocator Performance Work

[S.Pam]

No issues with compression afaik.

[Anvil]

Doesn't need guessing. Fedora is targeting Fedora 33 for default of BTRFS. https://fedoraproject.org/wiki/Changes/BtrfsByDefault

still has issues like compressing? my issue would be if a Blackout were to occur an you had a power failure would you lose anything ? they coul;d always revert it back to EXT4 if to many users have issues with BTRFS during the Beta

[mackal]

Sorry for the assumption. After a little looking, what I see is that swapon is rejecting swapfiles the kernel thinks are created with 'holes', which is a filesystem space optimization where space is not allocated for lots of contiguous nulls in a file. The complaints I saw seemed to relate to swapfiles created with fallocate(1), and were fixed by 'the recommended method' of using dd. I have always used dd since the dark ages for this purpose, so my test worked fine. I just tested with fallocate on kernel 5.8.2 and it rejected it with a log saying 'swapon: swapfile has holes'.

So, just to be clear, for me on kernel 5.8.2 a swapfile made with 'fallocate -l 1GB swapblob' is not accepted, but one created with 'dd if=/dev/zero of=swapblob bs=1024k count=1024' works with ext4.

Could have sworn I tried dd as well and that failed back when 5.7 was first released, seems to work now though /shrug

[mackal]

Probably you were thinking of btrfs, which allows swapfiles as of kernel 5.0 (with some caveats)

No, it broke with 5.7.

[mackal]

But is swapfile on ext4 fixed yet?

[BenjiWiebe]

will be interesting to see how long Fedora default to BTRFS , my guess is, it wont be long

Doesn't need guessing. Fedora is targeting Fedora 33 for default of BTRFS. https://fedoraproject.org/wiki/Changes/BtrfsByDefault

[nanonyme]

Typically new Ext4 features only were applicable to new data without reformat but you still could enable them, not sure if this will be different.

[loganj]

just curious: do you have to reformat the disk for new feature to be available?

[pkese]

Why is that?

Because 'feelings'.

[S.Pam]

Why is that?