From owner-chemistry-: at :-ccl.net Wed Mar 2 12:26:01 2022 From: "Susi Lehtola susi.lehtola-$-alumni.helsinki.fi" To: CCL Subject: CCL: Cloud backup in computational chemistry Message-Id: <-54619-220302002227-16618-fP2ARbDalyuVwuscDc1M5Q]![server.ccl.net> X-Original-From: Susi Lehtola Content-Language: en-US Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Date: Wed, 2 Mar 2022 00:22:12 -0500 MIME-Version: 1.0 Sent to CCL by: Susi Lehtola [susi.lehtola..alumni.helsinki.fi] On 3/1/22 15:35, Detlev Conrad Mielczarek detlevcm#,#googlemail.com wrote: > > Sent to CCL by: Detlev Conrad Mielczarek [detlevcm]![googlemail.com] > Please note, RAID is NOT a backup. > > The topic is fairly complex if done rigorously. Look up "bit rot" - data life is finite too. > Look up the risk of data corruption on a RAID system - or loss with say malware or error. > > The topic is not simple - unfortunately. > And then there is data lifetime on disks which is not necessarily a resolved question. > Tape is considered the best for long term storage at current - maybe archive quality DVDs. Yes, at the bare minimum you would want 2 NAS systems each running RAID 1, preferably with disk drives from different manufacturers. That way if there's a manufacturing error in a hard drive, it won't affect the whole array at once. But, an electrical failure or a fire would still wipe out the whole system. That's why you want backups in another physical location. I heard from an old Linux developer colleague that he had bunched up with a friend and set up a pair of home servers with 4 hard drives on RAID 5 each. They had encrypted partitions on each others' servers, which would be automatically be kept in sync: your home directory would also be encrypted onto your friend's server. You can't access their data, and they can't access your data, but you both enjoy the significant benefit of having your data automatically backed up elsewhere, and only have to put up the cost of setting up the servers if you can host a server in your home. -- ------------------------------------------------------------------ Mr. Susi Lehtola, PhD Adjunct Professor susi.lehtola|*|alumni.helsinki.fi University of Helsinki http://susilehtola.github.io/ Finland ------------------------------------------------------------------ Susi Lehtola, FT dosentti susi.lehtola|*|alumni.helsinki.fi Helsingin yliopisto http://susilehtola.github.io/ ------------------------------------------------------------------