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ninefathom | 3 years ago
This capability was something of which the lack on Linux has long puzzled me. Solaris actually implemented a very early incarnation of this ability (called "live upgrades" at the time from its original use case) back in the early '00s- in Solaris 8, and on top of UFS no less, if I recall correctly. It evolved over the next decade first adding ZFS into the mix, then finally morphing from the early "live upgrade" stuff into the full "boot environment" concept around 2010 with Solaris 11. FreeBSD implemented it around 2012, in the early days of their ZFS work. More than a decade ago. That puts Linux at least ten years behind the curve here, and arguably closer to twenty.
I'm a fan of using the right tool for the right job, and jumping freely between Solaris (or OpenIndiana nowadays), Linux, and FreeBSD for any given deployment is par for the course. Until now, all other things being equal, FreeBSD or Solaris would often win out if minimizing downtime* was a much higher priority than ease of replacing admins. Assuming that BE support in Linux matures quickly, that calculus has now swung strongly in Linux's favor.
*Re: minimizing downtime, if somebody is puzzled as to what I mean, think of the last time that you had a Linux installation fail to come back up to full operation after a borked round of package upgrades. It's not often, but it does happen occasionally. Now imagine that the time you spent getting back up and working, whatever it might have been, was reliably less than sixty seconds. Now imagine it's 2am, you're not even fully awake following a panicked phone call from the operations night shift, and your job hangs in the balance. Makes quite a difference.
ploxiln|3 years ago
There just hasn't been much demand for it. There are a bunch of other mechanisms used instead, like redundant systems and gradual rollouts, working with full system images (or container images) instead, etc.
For personal-ish systems, things are reliable enough, and if there is a problem you can't just stop updating, you'll need to fix it soon anyway. I've been updating a debian install on my home fileserver for 3 major debian releases, 5+ years ...
nortonham|3 years ago
>This capability was something of which the lack on Linux has long puzzled me.
Agreed. I recently tried out OI "hipster" and the way boot environments are integrated into caja (the file manager) with Time Slider was so smooth it got me thinking why something like it wasn't more popular in linux.
ninefathom|3 years ago
I find that it's a good fit for quite a few things, but if you're looking for a specific example: clustered Java application stacks, like ELK or Hadoop.
Zones, crossbow networking, SMF, and ZFS w/ BEs all working seamlessly together is a fantastic combination for easy-button admin of low- or zero-downtime clustered applications.
contingencies|3 years ago
I definitely recall using ZFS on FreeBSD in 2010, and no part of the experience suggested it was immature at that point. Full disclosure: used it explicitly for ZFS, and haven't used it since.