On Fri, Mar 23, 2018 at 09:40:34AM -0400, Austin S. Hemmelgarn wrote: > On 2018-03-23 08:25, hy...@lactose.homelinux.net wrote: > > "Ryan, Lyle (US)" writes: > > > > > The server has an 11TB filesystem to store the backups in. I should > > > probably be fancier and split this up more, but not now. So I've got my > > > holding, state, and vtapes directories all in there. > > > > In this scenario, I would think there's no point to a "holding" disk. > > > > I use a holding disk because my actual backup disk is external-USB and > > (comparatively) slow. So I backup to a holding disk on my internal > > SSD, releasing the client and the network as soon as possible, and then > > copy the backup to the backup drive afterwards. But in your case, I > > don't see any benefit. > There are two other benefits to having a holding disk: > > 1. It lets you run dumps in parallel. Without a holding disk (or some > somewhat complicated setup of the vtapes to allow parallel taping), you can > only dump one DLE at a time because it dumps directly to tape. > > 2. It lets you defer taping until you have some minimum amount of data ready > to be taped. This may sound kind of useless when working with vtapes, but > if the holding disk is on the same device as the final vtape library, > deferring until the dumps are all done (or at least, almost all done) can > help improve dumping performance, because the dump processes won't be > competing with the taper process for disk bandwidth. >>> End of included message <<<
3. If something happens to the data storage device(s), the holding disk (HD) can continue to collect your backups. My HD is big enough to hold about 4 typical runs. Should the storage outage be protracted and HD space gets low, amanda switches to "degraded" mode and only does incrementals. jl -- Jon H. LaBadie j...@jgcomp.com 11226 South Shore Rd. (703) 787-0688 (H) Reston, VA 20190 (703) 935-6720 (C)
