Using SANs and NAS

Chapter 7. NAS Backup and Recovery

At one time there were few backup and recovery options for NAS filers. If you were willing to manually swap tapes, you backed them up with locally attached tape drives and the dump command. If you wanted to integrate your NAS backups into your enterprise backup system, you backed them up via NFS or CIFS. These two options were relatively simple, but they left a lot to be desired. Thankfully, today’s landscape looks much different.

This chapter concentrates on the entire spectrum of data protection services available for filers today. Not all the features discussed here are available from all NAS vendors. In fact, some features are available on only one or two platforms. Since this market is so dynamic, This chapter will cover only general features; please contact vendors for specifics.

Snapshots and Mirroring

This section concentrates on two options you can use as a first line of defense against logical corruption and physical disk failure. Snapshots can give you multiple points in time to which you can recover instantly without a lot of overhead. Mirroring helps provide a standby system in case the primary system fails.

Snapshots

NAS-based snapshots are essentially the same as the snapshots discussed in Chapter 4. Here is a review of that discussion:

• Snapshots are a virtual copy of a filesystem. They require neither the space nor the I/O overhead of the backup mirrors discussed in the client-free section of Chapter 4.

• As long as the snapshot ...