[pve-devel] [PATCH installer] fix #1239: enhance swap on ZFS setup

Fabian Gr├╝nbichler f.gruenbichler at proxmox.com
Wed Jan 25 16:03:50 CET 2017


set properties according to upstream documentation

Signed-off-by: Fabian Gr├╝nbichler <f.gruenbichler at proxmox.com>
---
 proxinstall | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/proxinstall b/proxinstall
index 18df7bb..0642098 100755
--- a/proxinstall
+++ b/proxinstall
@@ -762,19 +762,26 @@ sub zfs_create_rpool {
 sub zfs_create_swap {
     my ($swapsize) = @_;
 
-    syscmd ("zfs create -V ${swapsize}K -b 4K $zfspoolname/swap")  == 0 ||
-	die "unable to create zfs swap device\n";
+    my $cmd = "zfs create -V ${swapsize}K -b 4K";
 
-    syscmd ("zfs set com.sun:auto-snapshot=false $zfspoolname/swap") == 0 ||
-	die "unable to set zfs properties\n";
+    $cmd .= " -o com.sun:auto-snapshot=false";
 
     # reduces memory pressure
-    syscmd ("zfs set sync=always $zfspoolname/swap") == 0 ||
-	die "unable to set zfs properties\n";
+    $cmd .= " -o sync=always";
 
-    # copies for swap does not make sense
-    syscmd ("zfs set copies=1 $zfspoolname/swap") == 0 ||
-	die "unable to set zfs properties\n";
+    # cheapest compression to drop zero pages
+    $cmd .= " -o compression=zle";
+
+    # skip log devices
+    $cmd .= " -o logbias=throughput";
+    # only cache metadata in RAM (caching swap content does not make sense)
+    $cmd .= " -o primarycache=metadata";
+    # don't cache anything in L2ARC
+    $cmd .= " -o secondarycache=none";
+
+    $cmd .= " $zfspoolname/swap";
+    syscmd ($cmd)  == 0 ||
+	die "unable to create zfs swap device\n";
 
     return "/dev/zvol/$zfspoolname/swap";
 }
-- 
2.1.4




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