[pve-devel] [RFC PATCH installer] proxinstall, common: remove deprecated fletcher2 as zfs checksum algorithm

[Christoph Heiss]

Fletcher-2 has long been deprecated and should not be used anymore
[0][1], so we probably should not offer it anymore too. It's been
deprecated since at least over 3 years, beyond that it's hard to find an
exact date.

Signed-off-by: Christoph Heiss <c.heiss at proxmox.com>

[0] https://openzfs.github.io/openzfs-docs/Basic%20Concepts/Checksums.html#checksum-algorithms
[1] https://people.freebsd.org/~asomers/fletcher.pdf
---
Sending this as RFC since it might warrant some discussions.

While digging into this a bit more, I reckon we should remove 'off' as
an option too. It's considered an "extraordinarily bad idea" [2] (for to
pretty obvious reason) and nobody should ever use it.

Might be a good idea, just so that users simply disable checksum "for
performance reasons" without knowing about the implications of this.

[2] https://openzfs.github.io/openzfs-docs/Basic%20Concepts/Checksums.html#disabling-checksums

 proxinstall                             | 2 +-
 proxmox-installer-common/src/options.rs | 3 +--
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/proxinstall b/proxinstall
index 01d4cfe..d6d5acb 100755
--- a/proxinstall
+++ b/proxinstall
@@ -1145,7 +1145,7 @@ my $create_raid_advanced_grid = sub {

     my $combo_checksum = Gtk3::ComboBoxText->new();
     $combo_checksum->set_tooltip_text("zfs checksum algorithm for rpool dataset");
-    my $csum_opts = ["on", "off","fletcher2", "fletcher4", "sha256"];
+    my $csum_opts = ["on", "off", "fletcher4", "sha256"];
     foreach my $opt (@$csum_opts) {
 	$combo_checksum->append($opt, $opt);
     }
diff --git a/proxmox-installer-common/src/options.rs b/proxmox-installer-common/src/options.rs
index afd12cd..98cd907 100644
--- a/proxmox-installer-common/src/options.rs
+++ b/proxmox-installer-common/src/options.rs
@@ -146,7 +146,6 @@ pub enum ZfsChecksumOption {
     #[default]
     On,
     Off,
-    Fletcher2,
     Fletcher4,
     Sha256,
 }
@@ -165,7 +164,7 @@ impl From<&ZfsChecksumOption> for String {

 pub const ZFS_CHECKSUM_OPTIONS: &[ZfsChecksumOption] = {
     use ZfsChecksumOption::*;
-    &[On, Off, Fletcher2, Fletcher4, Sha256]
+    &[On, Off, Fletcher4, Sha256]
 };

 #[derive(Clone, Debug)]
--
2.42.0