Quyen Nguyen wrote: > Hello, > > Quoting Scott Howard from his weblog > > "Flash archives are designed for quick deployment of like servers, > where like is defined in terms of the software installed, and not > (necessarily) the hardware involved. By design what is "restored" > from a flash archive is deliberately different to what was flashed, > with many of the OS configuration files being deliberately deleted > and/or re-created during the flash process. This includes things like > /etc/hosts, /etc/hostname.*, /etc/netmasks, /etc/path_to_inst, the > entire /dev and /devices trees and some others. > > So in effect, what you put in is NOT what you get back out. > > But the very definition of a backup/restore is that you get back > exactly what you started with. ufsdump (or any commercial backup > software) will give you a restored machine which looks exactly like > what you started with." > > Is that true? My impression from Sun's documentations is that you can > use flash archives to quickly install identical disk images on > identical workstation. >
Reviewing the blog entry you're referring to[1], yes, it's true, although it's a fairly fine distinction. Flash isn't a classic backup solution, as for most people backup means getting back *all* of the files *exactly* as they were at the time of the backup. Flash doesn't do that, it intentionally re-creates some files from scratch, because it is installing a clone of a system, not restoring exactly that system. On the other hand, some people find flash to be a better choice for some cases where backup has been the solution in the past; for example, disaster recovery scenarios, where you may not necessarily have an identical system on which to do the restore, but can come up with one that's similar enough to get things going again. This is possible because flash doesn't necessarily require that the systems be identical. For example, if you create a flash archive based on an installation with "All + OEM" as your software selection, you've got all the possible drivers for the platform, which allows the hardware to differ significantly between systems. Dave [1] http://blogs.sun.com/Doc/entry/flash_archives_v_s_backups
