Various notes on /usr unification

Posted Feb 28, 2012 8:51 UTC (Tue) by pflykt (subscriber, #2757)
Parent article: Various notes on /usr unification

When we focus on /usr, we tend to keep forgetting the trend of moving the old role of / into initramfs. The role of / has been a minimal system that contains enough tools to initialize a "multi-user" system, including a /usr partition that was not readable by the boot loader. With more complex setups reaching beyond RAID 1 on the / partition, initramfs has come to our rescue.

I don't see any signs of getting rid of / anytime soon, it just moves over to initramfs instead. And when all necessary repair tools are usable from an initramfs shell, it will all look just too familiar like the way it was in 1992.

Various notes on /usr unification

Posted Feb 28, 2012 22:03 UTC (Tue) by rvfh (guest, #31018) [Link] (1 responses)

On Xstations, / would be the strict necessary software to boot, and /usr would be mounted from THE server.

That also lead some embedded systems to making / the core boot stuff that remains read-only (with proper links in /etc such as /etc/mtab) and /usr where the real stuff takes place and upgrades can occur.

Various notes on /usr unification

Posted Aug 19, 2021 9:17 UTC (Thu) by immibis (subscriber, #105511) [Link]

And now initramfs would be the strict necessary software to boot, and / would be mounted from THE server.

I actually have one system which has a real partition instead of an initramfs. It works fine. Apparently the only problem is that the tools to maintain it don't exist.

initramfs typically terminates by mounting something else over / using the pivot_root syscall. But there's no reason only an initramfs can do that! You are free to install a minimal system locally and then have its init set up the network and NFS and then pivot_root to NFS.