Engine rocksdb not found

Hi,

I'm not sure if I missed something, but when I start the new 0.8rc1 (clean install) I receive the following errors:

```
[2014/07/15 20:36:23 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).createShards:873) createShards for space default: start: Thu Jul 10 02:00:00 +0200 CEST 2014. end: Thu Jul 17 02:00:00 +0200 CEST 2014
[2014/07/15 20:36:23 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).GetShardToWriteToBySeriesAndTime:842) No matching shards for write at time 1405449373000000u, creating...
[2014/07/15 20:36:23 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).GetShardToWriteToBySeriesAndTime:842) No matching shards for write at time 1405449373000000u, creating...

[2014/07/15 20:35:19 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).GetShardToWriteToBySeriesAndTime:842) No matching shards for write at time 1405449308000000u, creating...
[2014/07/15 20:35:19 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).createShards:873) createShards for space default: start: Thu Jul 10 02:00:00 +0200 CEST 2014. end: Thu Jul 17 0
2:00:00 +0200 CEST 2014
[2014/07/15 20:35:19 CEST] [INFO] (github.com/influxdb/influxdb/datastore.(*ShardDatastore).GetOrCreateShard:163) DATASTORE: opening or creating shard /opt/influxdb/shared/data/db/shard_db_v2/00001
[2014/07/15 20:35:19 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).GetShardToWriteToBySeriesAndTime:842) No matching shards for write at time 1405449318000000u, creating...
[2014/07/15 20:35:19 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).createShards:873) createShards for space default: start: Thu Jul 10 02:00:00 +0200 CEST 2014. end: Thu Jul 17 0
2:00:00 +0200 CEST 2014
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/datastore.(*ShardDatastore).GetOrCreateShard:170) Error opening shard: %!(EXTRA *errors.errorString=Engine 'rocksdb' not found)
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).AddShards:1075) AddShards: error setting local store: %!(EXTRA *errors.errorString=Engine 'rocksdb' not found)
[2014/07/15 20:35:19 CEST] [INFO] (github.com/influxdb/influxdb/datastore.(*ShardDatastore).GetOrCreateShard:163) DATASTORE: opening or creating shard /opt/influxdb/shared/data/db/shard_db_v2/00002
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/coordinator.(*RaftServer).doOrProxyCommandOnce:149) Cannot run command &coordinator.CreateShardsCommand{Shards:[]*cluster.NewShardData{(*cluste
r.NewShardData)(0xc21007a9a0)}, SpaceName:""}. Engine 'rocksdb' not found
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/coordinator.(*RaftServer).CreateShards:714) RAFT: CreateShards: %!(EXTRA *errors.errorString=Engine 'rocksdb' not found)
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/datastore.(*ShardDatastore).GetOrCreateShard:170) Error opening shard: %!(EXTRA *errors.errorString=Engine 'rocksdb' not found)
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).AddShards:1075) AddShards: error setting local store: %!(EXTRA *errors.errorString=Engine 'rocksdb' not found)
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/coordinator.(*RaftServer).doOrProxyCommandOnce:149) Cannot run command &coordinator.CreateShardsCommand{Shards:[]*cluster.NewShardData{(*cluste
r.NewShardData)(0xc210220380)}, SpaceName:""}. Engine 'rocksdb' not found
[2014/07/15 20:35:19 CEST] [EROR] (github.com/influxdb/influxdb/coordinator.(*RaftServer).CreateShards:714) RAFT: CreateShards: %!(EXTRA *errors.errorString=Engine 'rocksdb' not found)
[2014/07/15 20:35:20 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).GetShardToWriteToBySeriesAndTime:842) No matching shards for write at time 1405441814000000u, creating...
[2014/07/15 20:35:20 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).createShards:873) createShards for space default: start: Thu Jul 10 02:00:00 +0200 CEST 2014. end: Thu Jul 17 0
2:00:00 +0200 CEST 2014
[2014/07/15 20:35:20 CEST] [INFO] (github.com/influxdb/influxdb/datastore.(*ShardDatastore).GetOrCreateShard:163) DATASTORE: opening or creating shard /opt/influxdb/shared/data/db/shard_db_v2/00003
[2014/07/15 20:35:20 CEST] [INFO] (github.com/influxdb/influxdb/cluster.(*ClusterConfiguration).GetShardToWriteToBySeriesAndTime:842) No matching shards for write at time 1405441814000000u, creating...

```

Almost forgot:

I installed the rpm on Centos 6

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