Adam Tauno Williams wrote:
And you are wrong in that backups are only for recovering from destroyed data/equipment. Backups are archival, you may need them for research, audits, and legal action. Most of the times in my career I've restored from backup has not been because of failure of software or hardware but because someone wanted/needed to see a point-in-time or access to data that was expunged.
Yup. Most of my backup retrieval requests have not been of the "Oh no, the hard disk crashed!" variety. They've been more like, "Oh no! I need that file I accidentally overwrote two weeks ago!"
Much as you protest, this is where the industry is going.
Pure conjecture. I do see movement to SANs with remote replication - but that is redundancy, not backup. Data still has to be archived in a rotational fashion - it just has to be, period. And I am seeing no one doing that with disk. The only way to avoid that is to have truly massive off-site storage, which almost no medium sized company can afford.
I see two other uses for disk-based backups: - Quick restoration from on-site backup. If you have disk-based backup on-site, you eliminate the need to retrieve tapes from off-site for those "oops" moments. Restoring from disk is faster, as well, because tape has seek times measured in minutes instead of milliseconds. With compression and file pooling it's possible to archive several weeks of data on a reasonable amount of disk space. BackupPC is a pretty good implementation of this. - Disk-buffered tape backup. Often on large systems it simply takes too long to write a tape backup -- you can't fit it in the backup window, especially if you're verifying every tape after writing it. (You should be.) In that case it sometimes makes sense to quickly mirror the disk to another disk array, then back that up the contents of the mirror. This is being made obsolete by filesystems that support snapshots, though. In both these cases you still need tape or some other removable media for off-site storage. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org