This is a series of posts on the Promise SmartStor NS4600 home storage server. Previous posts:
- Hardware Review: Promise SmartStor NS4600 – Part I
- Hardware Review: Promise SmartStor NS4600 – Part II
- Hardware Review: Promise SmartStor NS4600 – Part III
The snapshot functionality is pretty much as you’d expect and can be found under the “Backup” menu option. Snapshot settings are set on a per-volume basis and unfortunately the maximum number for any one volume is four. This is somewhat limiting and could be pretty restrictive if the NS4600 was being used in a home/office environment where hourly backups would be more preferable.
This feature enables data to be backed up to and from external devices across either the USB or eSATA interfaces. Data from the external device is backed up to a named folder on the NS4600. Backing up from the NS4600 can either be a full or synchronised copy. This can be useful when wanting to ensure a copy of data is available outside of the NS4600, in case the device malfunctions or worst case, is destroyed or stolen.
Whilst the previous two features are useful, the one I could see more benefit from was NAS replication. This enables two NS4600 devices to replicate data between each other over the network. Setup of this feature is quite simple. One device acts as primary, the other as the secondary in a replication pair. There’s no ability to replicate in both directions at the same time as the feature is uni-directional. The screenshots show the setup of the replication feature and a replication task in progress. I had some trouble initially establishing replication as the documentation doesn’t make obvious what data is replicated. In fact it appears to be every file share in every volume and the target device needs to have an identical volume name structure to allow replication to work; so if the primary appliance as a VOLUME2, the target appliance must also have VOLUME2. Although replication is a useful feature, there are few shortcomings that should be addressed to make this a more usable. These would include:
- More detailed log information on the success/failure of a replication task. If replication fails, the only way to get detailed information on the failure is to have enabled email alerts. The management log provides insufficient detail on the failure reason. Email support might not always be easy for users to implement as it requires SMTP server details.
- More granular selection of the replication shares. I’d like to exclude some files from replication; for instance music files don’t need to be replicated necessarily, but accounts information does. Allowing at least share level replication would be a start.
- I’d like to be able to specify source and target folders. NAS replication is simply using rsync, so it should be possible to achieve. I like to be able to clearly identify which directories are backups of primary data to prevent multiple update issues.
- There doesn’t seem to be any way to stop replication once it has started. This could be a real issue if the replication task starts taking lots of network bandwidth and the only abort option is a reboot of the appliance.
Clearly Promise have realised that it’s essential to be able to secure data away from a single appliance. RAID and snapshots alone aren’t protection enough for device failure, theft or fire. Data copying also needs to be simple and no doubt in this regard the NS4600 replication is simple to establish. However this simplicity has also resulted in a lack of features, which needs to be addressed in future releases.
In the final article I’ll discuss some of the other features of the NS4600 and provide an overall summary of my thoughts.