What about NAS Backups?

At one time, I felt that NAS had a rather distinct disadvantage. While it did significantly reduce system administration requirements, it created a challenge in one particular area - backup and recovery. Since more NAS filers usually involve a stripped down (or significantly customized) version of the operating system, normal backup and recovery client software often isn't applicable. With a few exceptions, you can't simply buy client software from your backup vendor for your filer. Although this has gotten better, there was a time when the only way to backup your NAS appliance was to use rdump or to back it up via an NFS mount.

Even the advent of the network data management protocol (NDMP) didn't seem to help things at first. It usually meant locally attaching a tape drive to a filer and backing up that server's data to that tape drive. This often meant a significant reduction in automation. It didn't help that software vendors were slow to support NDMP, because they saw it as competition to their own client software.

However, a lost has changed in recent years. All major backup-software vendors support NDMP, and you can even use SAN technology to share a tape library between your filers and your other backup servers. Even if you're backing up your filers across the network, gigabit NICs that offloaded the TCP/IP processing from the host CPU make data transfer over the network much easier and faster. Jumbo frames also helped some vendors.

Another reason that backup and recovery of filers is now less a problem is that some NAS vendors introduced data-protection options equivalent to (and sometimes easier to use than) the options available on many UNIX or NT systems - including built-in shapshots, mirroring and replication. Therefore, for what it's worth, my respect for NAS has grown significantly in recent years.