From: Alan B. <aj...@ms...> - 2004-02-20 15:24:05
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On Fri, 20 Feb 2004, Johan Decock wrote: > Provided those DVD+R media remain readable over time. (We will follow up > on that and test them regularly) You'll need to. Many of our old CD-R backups are now marginal enough that it's difficult to read them and some of the failing discs are only 3-4 years old. DVD and CD are _not_ archival media, no matter how much they get touted that way. The only way to ensure a long life is to keep them in a cool dark place such as a film fridge - there's no guarantee they'll be readable after a fire, even in a data safe, as data safes generally allow the temperature to climb to 60C and that is high enough to kill most CD-R/DVD-R based media after only a few hours exposure (it will be at least 12 hours before a data safe can be opened after a fire, possibly as much as 48 hours) > Maybe it's not realistic of us to expect such a streamer to keep working > for more than 3 years. Our experience is that large drives last about 1.5-2 years, DATs range between 1 and 4 years, however it is highly dependant on how a drive is treated - drives which aren't in the server room die a lot sooner and so do drives which are only used occasionally. I believe it's dust/heat related in both cases. DVD is not an option for us. The Full backup I ran last night would consume over 450 of them alone and once the system is fully populated (I'm still testing) would be more than 2000 DVD-RWs @ 4.5Gb apiece, with possibly 10-20 being used at each incremental change. > Restoring from tape was always a very time consuming process (in two or > three steps, keeping one waiting while the tape was brought to the right > location to retrieve its contents. Bacula mostly automates that by memorising the location of the the backup you want. > On top of that one had to be very careful to not forget to put the right > tape for the night in, after doing a restore). This isn't usually a problem if you have an autochanger. If not and you're using DAT, etc - just get a second drive. Reserve one for backups and use the other for restores/general use. AB |