Rodrigo Barbosa <rodrigob at suespammers.org> wrote: > At least around here, a 120G DLT tape costs less than half > the price of an HD of the same capacity. Reality ... When you're talking 100GB, most of the higher capacity, leading-edge technologies are $50-100/cartridge, _regardless_ of the capacity. So you're better off going with the latest/fastest/biggest capacity when you're going to spend 4 figures. Right now, that's multi-vendor LTO revision 3 -- 400GB (800GB) at 80MBps (160MBps) native (2:1 hardware). DLT is slower and largely uni-vendor, HP, and even HP does LTO (and they do it better than DLT). DLT should only be considered for legacy media compatibility. More commodity 8mm AIT-2 and VXA-2 drives are just under $1,000, and are under 100GB, but then the tapes are still costly. So you have to consider where your "break even" point is when it comes to cost. For a single server, or a single backup server, that will only putting less than 100GB (so only 1 tape) maybe 1-2 times/month, you're okay. But if you need to off-site more than 100GB from multiple servers, make the $7-8K investment in TBs of disk storage on a dedicated backup server with a dedicated LTO-3 drive. Especially if you're putting 1+TB off-site, so it's 6+ tapes/month, possible dozens. The cost per GB per cartridge is well worth the LTO-3 initial cost. > Not to mention that tapes are much more reliable, since you > can store them on appropriate containers/safes. Yes, the whole reason for Removable Rigid Disk (RRD). 3.5" fixed disk cannot only not take the Gs, but it is _not_ designed to be off-line for weeks or months -- especially not after being rattled around. Now 2.5" fixed disks are getting better G tolerances, and are an interesting option. 80GB 2.5" disks go for under $100, so they are an option for smaller companies. I might recommend them in limited cases over going with extra on-line/near-line disk and a VXA-2 or AIT-2 drive. > They also don't have mechanical parts built in, so the they > are less likely to fail. Well, there _are_ still moving parts, just no mechanics. Some of the new 1" hard drives are less fragile, taking even 800Gs. > Of course, I mean good tapes, not the el-cheapo ones. By "el-cheapo" you mean? 4mm (DAT), QIC (?), 8mm (AIT, VXA), HIC (LTO?), [F]IC (DLT) -- there's a number that share the same moving part design. > HDs are not a reliable backup media, and never were. Commodity 3.5" fixed disk is designed for regular operation and limited G-forces, even with heads parked. > This is enough to show me it would be a waste of time to > show the flaws on your thinking. If you are looking at it > emotionaly, it is useless to explain anything to you. Disk and tape are not a versus, they are a complement. That's why I wrote the 2005 September Sys Admin article on VTLs, they are the evolution of _complete_ backup. I guess I need to follow up with a blog entry on "scenarios." -- Bryan J. Smith | Sent from Yahoo Mail mailto:b.j.smith at ieee.org | (please excuse any http://thebs413.blogspot.com/ | missing headers)