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On 2012-12-16, Bruce Hill wrote: |
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> On Sun, Dec 16, 2012 at 05:10:43PM +0200, Alan McKinnon wrote: |
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>> |
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>> That was the original reason for having / and /usr separate, and it |
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>> dates back to the early 70s. The other reason that stems from that time |
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>> period is the size of disks we had back then - they were tiny and often |
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>> a minimal / was all that could really fit on the primary system drive. |
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>> |
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>> Gradually over time this setup became the norm and people started to |
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>> depend on it, and more importantly, started to believe it was important |
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>> to retain it. It's their right to believe that. |
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>> |
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>> Recently I decided to measure if I still needed a separate /usr (I was |
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>> a long time advocate of retaining it). I'm in the lucky position of |
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>> having ~200 Linux machines, all distinctly different, at my disposal, |
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>> so I trawled through memory and incident logs looking for cases where a |
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>> separate /usr was crucial to recovery after any form of error. To my |
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>> surprise, I found none at all and those logs go back 5 years. |
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>> |
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>> So I got to change my mind (not something I do very often I admit) and |
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>> concluded that separate base and user systems (/ and /usr) was no |
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>> longer something I needed to do - the "system" - disks, hardware and |
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>> the software on the disks - was very reliable, and what I really needed |
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>> was ability to boot from USB rescue disks. I did find, not |
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>> unsurprisingly, that I also really needed /usr/local on a separate |
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>> partition but that's because of how we install our in-house software |
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>> here, plus our backup policies. |
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>> |
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>> It also goes without saying that these days we |
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>> need /home, /var, /var/log and /tmp to all be on their own filesystem, |
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>> and we need that more than ever. |
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>> |
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>> I thought I should just toss that in the ring for people who are |
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>> undecided where they stand on the debate of separate / vs /usr. It's |
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>> what I found on our production, dev and staging servers, plus a whole |
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>> lot of people's personal workstations (sysadmins and devs). The |
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>> environment is a large corporate ISP that defies categorization, we |
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>> almost have at least one of every imaginable use-case for running on |
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>> Linux except something in the Top 100 SuperComputer list. I reckon it's |
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>> about as representative as I'm ever gonna see. |
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>> |
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>> People are free to draw their own conclusions as always, and real data |
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>> is valuable in arriving at those conclusions. YMMV. |
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> |
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> Thanks for sharing your experience, and not just your emotions. One of my |
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> favorite quotes is, "A man with an experience is not subject to a man with an |
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> argument." |
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My thanks, too! There's nothing like reading on some actual experience |
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with this. So this was once the reason to keep / separate. Not that |
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important anymore (but this is still no excuse to force people to keep |
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/usr in the same filesystem). |
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|
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-- |
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Nuno Silva (aka njsg) |
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http://njsg.sdf-eu.org/ |
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