On Mon, Nov 13, 2023 at 10:15:30AM +0100, Daniele B. wrote: > In few words, when the matter is saving the data of one 1 disk the best > solution is adopt a backup strategy for that purpose.
Yes, this is true. I answered the OPs direct question about how to create the raid mirror, but that was _not_ intended as an endorsement of using raid to solve any particular problem. In very simple terms, a raid-1 mirror is useful for protecting data which is often changing, (E.G. busy mail spools), where backups would immediately become out-dated, (although you should make regular backups of that data anyway, in addition to having the mirror). Raid-1 is also useful in some situations where you need high availability of data even though that data is unchanging and easily restored from a backup. An example of high availability of a large and mostly unchanging database might be a music repository for a radio station that is using digital playout, where they cannot risk going silent just because one hard disk broke, but the actual data would be easily restored from backups if a complete system failure did occur. Also note that using multiple disks instead of a single disk can and often does _increase_ the risk of any particular failure. Any one of the disks could develop a fault which takes the host controller out or even makes the PSU explode. Any one of the disks could have firmware issues that cause silent data corruption, and the more disks you have the more likely it is that one of them will suffer such a problem. > If you are on > sticks copy machine by three slots are also a solution. Running an OpenBSD system entirely from USB sticks, and using a copy machine to make backups is not a good suggestion for general usage. Just do a normal installation on a normal hard disk and make normal backups. And don't just use $HOME as an endless rubbish dump for old data. $HOME is for work in progress. Finished stuff should be archived elsewhere and taken out of the regular backup loop. P.S. Daniele, please fix your mailer's reply-to: header.
