Remote Management

Persistence of systems is provided by overrides and updates managed remotely. Secure online storage is used. No personal data is held.

A system registry controls hardware used, handles different domains, subnets, gateways and sites, permits aliases, and simplifies media.

What Changes Why Necessary
Level 1 Reissue New medium (CD or stick) New Debian release or package cache
(packages can also be updated in 2, 3, or even 4)
Change to 'hook' (very unlikely)
Level 2 Reboot New instance from online /custom Power or hardware failure or system crash
All-system startup changes
Registry changes
Level 3 Update Online /custom to existing instance System-specific fixes or development,
of database, applications, web publishing, etc
Level 4 Patch Just existing instance One-off - persistence is not needed or wanted

Factors determining whether media are reissued include stability, required functionality, and security of OS software.

The online version of /custom overrides the instance in 2, or updates it in 3. Essentially the same thing is happening but there are subtely different implications. During a restart (reboot) initialisation scripts are deployed, whereas reinitialisation may be required after an update. An automatic update occurs overnight or one may be requested at any time.

Remote management eases the logistics of bringing out new versions and getting them to site, not being able to reboot when necessary, or having to reboot when unnecessary (eg due to power cuts). Systems can now be run anywhere and maintained anywhere.

Before remote management, 'patching' was the only way of making many important changes. Rebooting was either impracticable or undesirable, but often necessary. And the only system persistence was provided by the boot medium.