From 121d6b078ec1aba8fdb4aa6058f649fe307b8fb7 Mon Sep 17 00:00:00 2001
From: Scott Worley <scottworley@scottworley.com>
Date: Sun, 7 Jun 2026 23:41:38 -0700
Subject: [PATCH] Quantify squashfs' efficiency

---
 modules/qemu-vm-isolation.nix | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/modules/qemu-vm-isolation.nix b/modules/qemu-vm-isolation.nix
index ed6800e..77db2f5 100644
--- a/modules/qemu-vm-isolation.nix
+++ b/modules/qemu-vm-isolation.nix
@@ -68,9 +68,12 @@ in {
       description = ''
         What filesystem to use for the guest's Nix store.
 
-        erofs is more compact than ext4, but less mature.
-
         squashfs is best, but requires patches to set the filesystem label.
+
+        ext4 images are ~4x larger than squashfs images.
+
+        erofs images are only ~2.5x larger than squashfs images, but erofs is less mature than either squashfs or ext4.
+
       '';
       type = lib.types.enum [ "ext4" "erofs" "squashfs" ];
       default = "ext4";
-- 
2.51.2