On 2024-07-24, 04-psyche.tot...@icloud.com <04-psyche.tot...@icloud.com> wrote: > Hi all, > > I have a machine that will be placed in a remote location, and have no > physical access to. The connection will be made through ssh only. > > I'd like to make it as resilient to failure as possible. > > A big concern to me is for a disk failure to happen (say a power > outage), and the machine to be rebooted in single user mode. At that > point, the machine has no network access, and so I lose contact to it.
If there's an actual disk failure, you're going to have to visit. I guess you mean "dirty filesystem that requires changes before it can be marked clean". > Is there any way to disable going to single user mode when fsck is not > happy? No. You can reduce the chance of fsck failing by: - reduce writes to mounted filesystems: noatime, use memory buffers or network for syslog, use mfs for things like /tmp /var/run - mounting filesystems read-only where possible Sometimes people modify /etc/rc to use "do_fsck -y" instead of just "do_fsck" on systems like this. (imho: if the only thing you'd do when running fsck manually is hit 'F' or keep hitting 'y' then this change is no worse, though some people don't like it). > Is it reasonable to change the /etc/fstab to modify the fsck flag from > 1 and 2 to 0, to bypass the fsck checks ? If a filesystem is marked "dirty" you can't mount it read-write. > Alternatively, is there a way to have ssh access in single user mode? Sure, start network and run sshd. You may be able to do this from /etc/profile. You just need someone/something to press enter to the question about running the shell... On 2024-07-24, Crystal Kolipe <kolip...@exoticsilicon.com> wrote: > The normal way to handle this and other boot-related problems is with a serial > connection from another machine that is still accessible via the network. > > Depending on your budget, what this system is being used for, and the > connectivity that is available at the remote location, there are various ways > of making that happen. Exactly. (Note that some consumer/small business-ish routers can handle running as a serial console server over a USB/RS232 interface - e.g. picocom and USB serial port drivers can often be installed on openwrt - routeros has /system serial-terminal or /system special-login).
