There are multiple UPS HAT boards available for the Raspberry Pi. Most have a lithium battery and can run the board for 10 minutes or more, enough time to shut down the RasPi. One key would be to make sure the UPS board you choose can supply more than enough current for the max load of the RasPi board you use. The new RasPi 4B draws more current than the previous models. Doug. On 12/12/19, tclug-list-request at mn-linux.org <tclug-list-request at mn-linux.org> wrote: > Send tclug-list mailing list submissions to > tclug-list at mn-linux.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://mailman.mn-linux.org/mailman/listinfo/tclug-list > or, via email, send a message with subject or body 'help' to > tclug-list-request at mn-linux.org > > You can reach the person managing the list at > tclug-list-owner at mn-linux.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of tclug-list digest..." > > > Today's Topics: > > 1. Re: Distros for rPi4 (was Old man's confusion solved) (Iznogoud) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 11 Dec 2019 20:36:22 +0000 > From: Iznogoud <iznogoud at nobelware.com> > To: Ryan Coleman <ryan.coleman at cwis.biz> > Cc: TCLUG Mailing List <tclug-list at mn-linux.org> > Subject: Re: [tclug-list] Distros for rPi4 (was Old man's confusion > solved) > Message-ID: <20191211203622.GA19965 at nobelware.com> > Content-Type: text/plain; charset=utf-8 > >> >> I use no slower than Class 10 mSDHC cards in mine. Anything slower takes >> for-ev-er to image. >> > > Right-on. I use my laptop for its card-reader/writer. Any ideas on one that > I > should attach to desktops? > > >> There’s no way to add a SATA drive to the Pi without doing it over USB so >> there’s no benefit to that other than capacity to doing it that way - >> you’re probably better set using it as secondary storage and not running >> the OS from it. That’s the plan with my projects. >> > > Great advise. And this is also my conclusion. I want to OS to boot and > rebuild > the RDWR partitions/mount-points so that I never corrupt the system itself, > which should run from RDONLY mount-points. > > But where the data lives will be the USB-drive. That is why I need a robust > shutdown of the FS. > > >> I’ve run all my stuff off a massive 12VDC LGM battery for days at a time >> without issue and, to be fair, shutting down improperly is something the >> Pi just doesn’t have to worry that much about. Yes files get left open >> sometimes but I’ve never had one fail because of a file issue… entire >> cards have failed but never a boot failure caused by locked files. >> > > I had not looked closely on the booting sequence of the RPi to really know. > But I think you are right, that it has most of the OS in RDONLY mounts. But > data can be corrupt if collecting data is what one is doing. > > Good pointer on the battery too. What I would like is to have a circuit to > monitor battery remaining capacity and attach it to the RPi itself. Info on > something like that? > > >> Tweaking can be done directly on the memory card, if you feel you have to, >> but I use SSH connections for my non-Zeroes to do my configurations if I >> don’t have a KVM handy. >> > > I have done both. Remounting the partitions RW from a running system works > fine. What would be best is if I had a virtualization/emulation of the RPi > so that I can do all my booting testing on a VM. Ideas on that? > > Thanks so much. This is great info! > > > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > TCLUG Mailing List - Minneapolis/St. Paul, Minnesota > tclug-list at mn-linux.org > http://mailman.mn-linux.org/mailman/listinfo/tclug-list > > > ------------------------------ > > End of tclug-list Digest, Vol 180, Issue 6 > ****************************************** > -- I vote the Second Amendment FIRST! The things they do not tell you are usually the clue to solving the problem.