diff --git a/ops/nixos/lib/blade.nix b/ops/nixos/lib/blade.nix
index f6273bf144..3ba3bd2bcc 100644
--- a/ops/nixos/lib/blade.nix
+++ b/ops/nixos/lib/blade.nix
@@ -48,6 +48,10 @@ in {
         device = device;
         fsType = "zfs";
       };
+      tmpfs = size: {
+        device = "none";
+        fsType = "tmpfs";
+        options = [ "defaults" "size=${size}" "mode=755" ];
     in {
       "/" = zfs "tank/local/root";
       "/tmp" = zfs "tank/local/tmp";
@@ -58,6 +62,8 @@ in {
         device = "/dev/disk/by-label/boot";
         fsType = "ext4";
       };
+      "/var/log" = tmpfs "2G";
+      "/var/cache" = tmpfs "16G";
     } // (lib.optionalAttrs (config.services.ceph.osd.enable || config.services.ceph.mgr.enable || config.services.ceph.mon.enable || config.services.ceph.mgr.enable) {
       "/var/lib/ceph" = {
         device = "/dev/disk/by-label/var-lib-ceph";