[pbs-devel] [PATCH proxmox-backup 3/5] file-restore: increase RAM for ZFS and disable ARC

[Stefan Reiter <s.reiter@proxmox.com>]

Even through best efforts at keeping it small, including the ZFS tools
in the initramfs seems to have exhausted the small overhead we had left
- give it a bit more RAM to compensate.

Also disable the ZFS ARC, as it's no use in such a memory constrained
environment, and we cache on the QEMU/rust layer anyway.

Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
---
 src/bin/proxmox_file_restore/qemu_helper.rs | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/bin/proxmox_file_restore/qemu_helper.rs b/src/bin/proxmox_file_restore/qemu_helper.rs
index c9d816ca..64d8e909 100644
--- a/src/bin/proxmox_file_restore/qemu_helper.rs
+++ b/src/bin/proxmox_file_restore/qemu_helper.rs
@@ -188,11 +188,10 @@ pub async fn start_vm(
         "-initrd",
         &ramfs_path,
         "-append",
-        if debug {
-            "debug panic=1"
-        } else {
-            "quiet panic=1"
-        },
+        &format!(
+            "{} panic=1 zfs_arc_min=0 zfs_arc_max=0",
+            if debug { "debug" } else { "quiet" }
+        ),
         "-daemonize",
         "-pidfile",
         &format!("/dev/fd/{}", pid_fd.as_raw_fd()),
@@ -240,9 +239,9 @@ pub async fn start_vm(
     } else {
         // add more RAM if many drives are given
         match id {
-            f if f < 10 => 128,
-            f if f < 20 => 192,
-            _ => 256,
+            f if f < 10 => 192,
+            f if f < 20 => 256,
+            _ => 384,
         }
     };
 
-- 
2.30.2