backup script for kernel snapshots to s3

config/backup.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=Mixin Kernel Backup Service
+After=network.target
+
+[Service]
+User=one
+Type=simple
+ExecStart=/user/bin/mnm run '/home/one/bin/snapshots.sh'
+Restart=on-failure
+LimitNOFILE=65536
+
+[Install]
+WantedBy=multi-user.target

config/backup.timer

@@ -0,0 +1,11 @@
+[Unit]
+Description=Mixin Kernel Backup Timer
+
+[Timer]
+Unit=mixin-backup.service
+OnCalendar=*-*-* 00:00:00
+Persistent=True
+RandomizedDelaySec=300
+
+[Install]
+WantedBy=timers.target

config/config.example.toml

@@ -14,7 +14,9 @@ cache-ttl = 7200
 [storage]
 # enable badger value log gc will reduce disk storage usage
 value-log-gc = true
-# compaction level should be increased when data too big can badger panic
+# max levels should be increased when data too big and badger panic
+# increase the level to 8 when data grows big to execeed 16TB
+# the max levels can not be decreased once up, so be cautious
 max-compaction-levels = 7
 
 [network]

config/config_test.go

@@ -18,6 +18,9 @@ func TestConfig(t *testing.T) {
 	require.Equal(4096, custom.Node.MemoryCacheSize)
 	require.Equal(7200, custom.Node.CacheTTL)
 
+	require.Equal(true, custom.Storage.ValueLogGC)
+	require.Equal(7, custom.Storage.MaxCompactionLevels)
+
 	require.Equal("mixin-node.example.com:7239", custom.Network.Listener)
 	require.Len(custom.Network.Peers, 26)
 	require.Equal("lehigh-2.hotot.org:7239", custom.Network.Peers[25])

config/snapshots.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+sudo systemctl stop mixin-archive || exit 1
+
+tar cf - -C /mnt/archive/mixin snapshots | s3cmd put - s3://mixin/snapshots/kernel.tar.new || exit 1
+
+s3cmd mv s3://mixin/snapshots/kernel.tar.new s3://mixin/snapshots/kernel.tar || exit 1
+
+s3cmd setacl s3://mixin/snapshots/kernel.tar --acl-public || exit 1
+
+s3cmd la --recursive || exit 1
+
+sudo systemctl restart mixin-archive

storage/badger.go

@@ -58,7 +58,7 @@ func openDB(dir string, sync bool, custom *config.Custom) (*badger.DB, error) {
 	// for level up to max levels: sum(base * (multiplier ** level))
 	// increase the level to 8 when data grows big to execeed 16TB
 	// the drawback is huge memory usage increases when 1 level up
-	// the max levels can be decreased once up, so be cautious
+	// the max levels can not be decreased once up, so be cautious
 	opts = opts.WithBaseLevelSize(16 << 20)
 	opts = opts.WithLevelSizeMultiplier(16)
 	opts = opts.WithMaxLevels(7)