Last night I watched almost the entire 5 hour live webcast announcing Oracle's strategies regarding the Sun Microsystems acquisition. As a near-evangelist for Sun and Solaris, I'm very happy with the deal finally going through and even happier that most of what Oracle said makes sense to me as a customer.
As I originally blogged, I was hoping to use EMC snapshots to perform server-less/network-less backups. EMC provides two main tools for managing snapshots in this type of situation:
The PowerSnap Module supposedly automates taking snapshots for the purpose of backups, while Replication Manager supposedly provides a much more robust package.
With Replication Manager you might create a policy to take a snapshot every five minutes, keep the last 10, and use those for backups whenever necessary.
To make a long story short, Replication Manager is useless for LUNs with ZFS. According to EMC, this won't change in the near future. PowerSnap also has no support for taking snapshots of LUNs with ZFS on them so basically EMC has no server-less backup offerings for Solaris with ZFS.
I've been paying a lot of attention to this site since I switched platforms and somehow people are finding some fairly irrelevant content on my site for the search terms making path persistent in solaris 10 so I figured I better put some real answers up.
Whether you are dealing with disk I/O in reading the data from the disks, or CPU for compressing or encrypting the data (or both- remember to compress and then encrypt!), or network for transferring the data to a backup server, the added load of a backup on your production servers is unwelcome. For this reason, the period of time during which backups can be made, aka. backup window, may be limited- even severely.
You may say, "It only takes me X hours to do a full backup of everything", but over time backup windows are notorious for becoming too small. Backups are split over multiple days, technologies upgraded, etc. When planning a backup strategy, my approach is to eliminate the backup window altogether- that is do whatever you can to take the backup off the production hardware altogether.
Storage Snapshots are one method for taking the production servers out of the backup equation. By creating a consistent, point in time snapshot on your storage, and mounting it on your backup server, you can backup your data using your backup server's resources while your production servers continue as usual.
Caveats of this method in general are:
Someone currently building an internal development environment required some integration between servers using SSH and the webservd user.
He came to me when he saw that the default home directory for the webservd user is /. He didn't want to create a /.ssh/authorized_keys file and I didn't blame him. My first reaction was to change the home directory but I didn't want to break something so I opened up Google and found something incredible.
DISCLAIMER: The following is quoted from documentation at docs.sun.com (emphasis is mine). I do not recommend you actually listen to it's instructions: