From: Johan D. <jd...@ab...> - 2004-02-20 16:08:33
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We are planning to copy all or most of them over to new DVD-Rs after two years. We keep them in the dark, but at room temperature. To be on the safe side, we would have to do exactly the same with tapes. One tape cost 30 euros. We can buy a lot of DVD-Rs for that money. Of course the tape can be reused. We are lucky that the volume of the essential data that we want to keep around for say 10 years is very low and will easily fit in the 4 GB limit. If there is going to be a fire, we have half of them in a location 20 kilometers away. We are not using DVD+R media for the daily and weekly backups. Those go to files on fixed and removable hard disks. Johan From: Alan Brown <aj...@ms...> on 20/02/2004 15:17 GMT To: Johan Decock/Abis@Abis cc: bac...@li... Subject: Re: [Bacula-users] wanted: Open Source disk to disk backup for Windows 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 -------------------------------------------------------------------------- ABIS Training & Consulting website: http://www.abis.be - e-mail: tra...@ab... tel: Belgium: (+32)-16-245610 - The Netherlands: (+31)-348-435570 fax: Belgium: (+32)-16-245691 - The Netherlands: (+31)-348-432493 -------------------------------------------------------------------------- |