Kari Laine ha scritto: > On Sun, Oct 19, 2008 at 7:02 AM, nando <[EMAIL PROTECTED]> wrote: > > >> but use a large block size >> like 8192 or 32768. It doesn't have to be a perfect binary size. >> True, it does not have to be a perfect power of two, but I suspect that good boundaries optimize disk reading (well, this is of scarce importance while checksumming with a complex algorithm).
> Also there is lot of duplication in disks I dont't want same data backed up > many times on DVDs. By the way does anyone have an idea how long lived a dvd > is? > I don't know much DVDs, but I know for sure that CDs are about the worst media in respect of indurance. I've read an article which compared media: paper is not bad (hundreds of year), those old documents written on animal skins (don't know the name in english) endure thousands of year. Nowadays, magneto-optical media are good - they need both magnetic fields and laser together to be written/erased, while harddisks and floppies (zips included) suffer from magnetic fields, and CD/DVDs suffer light, dust, physical damage, heat - everything. CD/DVDs are not true randomly writable (ok, perhaps for backups it doesn't matter). Anyway, the expected life for a CD was seven (7) years. I think DVDs are near to that. Flash memory is very good - it suffers nothing (apart lightning), unfortunately is expensive. Anyway I have always hated CDs and DVDs, almost the same as I hated floppies; totally unreliable. It is happened to me to go to a customer carrying three (3) copies of the same data, just to find that noone was good, thanks also to the poor implementation of PCs hardware... But seems that everybody trusts CDs, so may be I am wrong. Salut, Doriano ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Gambas-user mailing list Gambas-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/gambas-user
