On Fri, Dec 29, 2017 at 12:28:33PM -0800, Chris Miller wrote: > Hi Folks, > > Just setting things up, and I think I ran out of docs... > > I have no tape drives, so that means "vtape", which is fine, as long as I can > size the vtape volume to be no larger than and no smaller than the current > backup under consideration. Is this possible? Seems like a silly question, > but physical tapes have a specific size and a small backup will result in > surplus tape and a large backup will result in multiple volumes. I'd like to > avoid both situations. > > I found very little documentation. In fact there was so little, that I think > I saw all of it this morning. I have found: > http://wiki.zmanda.com/index.php/User_documentation Is there a hidden archive > that I haven't found?
Welcome to amanda Chris. Two comments first. The size of a vtape is its "maximum" size. A 100GB vtape does not take up 100GB of disk unless it contains a backup of that size. Working with multiple vtapes and virtual changers is a breeze in amanda. Don't try to avoid multiple tape backups. Suppose you were used to working with 100GB physical tapes. You may feel inclined to create 100GB vtapes in amanda. You may do that and if your disk is 1TB, you would probably create 10 vtapes. Explore 2 possibilities. Using 100GB vtapes, telling amanda to use only 1 vtape per run, you may discover most (all?) your vtapes are not full. After you gain some data from backups you may find your tapes average well under 100% full and you can allocate more vtapes than 10 x 100GB to your 1TB drive. As a real example, I have 20TB of storage for vtapes and 240 x 100GB vtapes. The 6 disks average 75-80% full even though I have 20% more vtapes than I "should". Another possibility is to allocate vtapes of 10 (or 20GB) and tell amanda that it can use up to 10 (or 5) vtapes per run. Also tell amanda that DLEs* may be split across multiple tapes using "chunks" of about 10% or 20% the size of the vtape. This would be an efficient use of your storage. A backup totalling 30GB would take 3 vtapes, 90GB would take 9. Each vtape except the last would be filled to within 1 "chunk"-size. Good Luck, HTH, Jon * DLE == Disk List Entry, the unit of backup for amanda. A DLE may be a file system (say / the root fs) or other more complex entries (like root but not /var or /opt or /usr/local which are backed up in other DLEs -- Jon H. LaBadie j...@jgcomp.com 11226 South Shore Rd. (703) 787-0688 (H) Reston, VA 20190 (703) 935-6720 (C)
