On Thu, 2024-01-18 at 13:26 +0100, Ralph Aichinger wrote: > Hello fellow Debian users, > > On Thu, 2024-01-18 at 12:18 +0100, hw wrote: > > > Always use an UPS. > > > Here I have a somewhat contrarian view, I hope not to offend too much:
It's not offending, you merely have a different opinion. > For countries with stable electricity supplies (like Austria where I > live) having a small UPS might actually lead to more problems instead > of less, unless you are putting a lot of effort into it. Very often > have I had problems with UPSes, e.g. batteries dying, the UPS going > into some self test mode and inadvertedly shutting down, etc. I've never had issues with any UPS due to self tests. The batteries need to be replaced when they are worn out. How often that is required depends on the UPS and the conditions it is working in, usually every 3--5 years. I rather spend the money on new batteries (EUR 40 last time after 5 years) every couple years rather than spending thousands on replacing the hardware when a power surge damages it which could have been prevented by the UPS, and it's better to have the machines shut down properly rather taking risks with potential data loss, regardless of file systems and RAID setups in use. The hardware is usually extremely difficult --- and may be impossible --- to replace. On top of that, noone pays for the time and effort lost, and even someone did, I'd rather keep my hardware instead of going to all the lengths required to replace it. Loosing hours of work due to power outages can also be an issue, and nobody pays for that, either. > I've had no external power outage in the last 5 or 10 years, but a UPS > often needs at least one battery replacement during that time. Outages are (still) rare here, but it suffices to trigger a fuse or the main switch when some device shorts out, or someone working on the solar power systems some of the neighbours have, causing crazy voltage fluctuations, or a lightning strike somewhere in the vinicity or whatever reason for an UPS to be required. Way too many times than I could count my UPSs saved me and the hardware from power supply problems, so I can't recommend to go without one. It doesn't matter how stable you think the power grid in your country is. > [...] > Here I also doubt if this is a wise suggestion for the typical home > or small office user. RAID leads to lots and lots of complexity, that > is often not needed in a home setup. RAID isn't as complicated as you think. Hardware RAID is most simple, followed by btrfs, followed by mdadm. With hardware RAID I can instruct someone who has no idea what they're doing to replace a failed disk remotely. Same goes for btrfs and mdadm, though it better be someone who isn't entirely clueless. More importantly, the hassle involved in trying to recover from a failed disk is ridiculously enormous without RAID and can get expensive when hours of work were lost. With RAID, you don't even notice unless you keep an eye on it, and when a disk has failed, you simply order a replacement and plug it in. It's not like you could go to a hardware store around the corner and get a new disk same or next day. Even if you have a store around, they will need to order the disk, and that can, these days, take weeks or months or longer if it's a small store. The only way to get a replacement is ordering online, which requires that your computer still works and that you have access to your passwords. > I'd rather have a working backup setup with many independent copies > before I even start thinking about RAID. Yes, disks can fail, but > data loss often is due to user error and malware. That is simply wrong. RAID doesn't protect you from malware, and nothing protects you from user error. If you have data losses from malware and/or user error more often than from failed disks, you're doing something majorly wrong. > RAID helps very little with the latter two causes of data loss. And > all too often have I seen people mess up their complicated RAID > setups, because they pulled the wrong disk when another one broke, > or because they misinterpreted complicated error messages, creating > unnecessary data loss out of user error by themselves. This shows that you have no experience with RAID and is not an argument. Making backups is way more complicated than RAID. You can way more easily overwrite the wrong backup or misinterpret error messages of your backup solution than you can pull the wrong disk from a RAID or misinterpret error messages from your RAID. How exactly would you pull the wrong disk from a RAID and thus cause data loss? Before you pull one, you make a backup. When the disk has been pulled, its contents remain unchanged and when you put it back in, your data is still there --- plus you have the backup. Sure it can sometimes be difficult to tell which disk you need to replace, and it's not an issue because you can always figure out which one you need to replace. You can always tell with a good hardware RAID because it will indicate on the trays which disk has failed and the controller tells you. > As a home/SOHO user, I'd rather have a working backup every few hours > or every day than some RAID10 wonder that makes me lose more time on > reading RAID documentation, and ordering spare drives (you've got > one of those spares for each array, do you?) than is actually lost by > not being able to restore to the exact last minute before a hard disk > died. No, I generally don't have spares, and I don't leave my backup server running all the time to make backups every few hours or every day because electricity is way too expensive, plus it's somewhat loud and gives off quite a bit of heat. How often do you verify that you can actually restore everything from your backups, and how do you do that? Yes, my setup is far from ideal when it comes to backups in that I should make backups more frequently. That doesn't mean I shouldn't have good backups and that UPSs and RAID were not required.
