On Thu, Jan 14, 2016 at 6:49 AM, Steve Langasek <[email protected]> wrote: > On Wed, Jan 13, 2016 at 11:00:16PM +0100, Martin Pitt wrote: >> Ben Howard [2016-01-13 14:26 +0200]: >> > On the Ubuntu Cloud Images, we have a request to make /tmp a tmpfs. The >> > rationale, from the bug: >> > * Performance - much faster read/write access to data in /tmp >> > * Security - sensitive data would be cleared from memory on boot, >> > rather than written (leaked) to disk -- important for encryption >> > scenarios > >> > Since the Ubuntu Cloud Images are used by a wide number of users, I >> > wanted to gather feedback and gather consensus on whether or not we >> > should make this change. > >> I really wish we would do this in general for new installs, at least >> as the first thing after releasing 16.04 LTS. I also do this on my >> boxes, not only for the reasons above [1], but also because it is much >> more power efficient -- as I literally work in /tmp a lot of my time >> the disk doesn't need to spin up often. > >> The main reason AFAIK why we didn't yet do that was the concern that >> there is some broken software out there which potentially dumps really >> large files into /tmp (yes firefox, I'm looking at YOU!). These would >> need to be fixed to go to /var/tmp. This is a chicken-and-egg problem, >> though: We won't find out what's broken until we actually enable it on >> real-life installations. This problem applies to cloud image use cases >> just as much as desktop or "classic" servers. > >> My gut feeling is that we should do it if there is ≥ 4 GB RAM, so that >> /tmp as at least 2 GB of space (That should be a rather simple >> installer/cloud-init decision?). We don't want to do this on small >> embedded devices with 512 MB of RAM or so, but there is absolutely no >> reason to not do it on beefy servers or laptops. > > As a data point, I used to have my /tmp on tmpfs while I still had a > spinning disk, in order to address the power usage issues of disk flushing. > I found it to be a least-bad option which led to serious degradation of > desktop interactivity in the face of even moderate memory usage (at the > time, with 4GB RAM), and not because of excessive /tmp usage. > > And as others in this thread have noted, this same problem can occur in > cloud instances.
Definitely. /tmp on tmpfs saves energy when you have a spinning HDD, and extends the life of your SSD by reducing the number of NAND flash writes! -- ubuntu-devel mailing list [email protected] Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel
