[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
As for encrypting swap created by swapspace, I have a question: http://askubuntu.com/questions/726577/how-can-you-setup-encrypted-swap- with-swapspace -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
Dropping this as won't fix. ** Changed in: livecd-rootfs (Ubuntu) Status: Triaged => Won't Fix -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
Let's not move forward with this right now. This decision needs more data and more consensus before being actioned. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
If user has chosen encrypted home directory during installation of Ubuntu, he/she probably wants encrypted swap, too. I am not sure, if that is possible with swapspace. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
swapspace sounds cool. I'll try it on my next installation of Ubuntu instead of reserving a separate partition. I think the Ubuntu installer could have an option for making /tmp a tmpfs and for making suitable swap configuration for that thus adapting to all needs. I use noatime option for filesystems that may have read operations on SSD to reduce wear, but that might not work in every setup. I think also notebooks benefit from such optimizations, as they tend to have more often only SSD as local mass storage. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
** Description changed: In Ubuntu, we have always cleared /tmp on every boot. As such, on servers, by default /tmp should actually be a tmpfs entirely in RAM, when there is enough memory in the system. This threshold should be configurable by the end user (in cloud-init?), and default - threshold of ~2GB. + threshold of ~3GB. Read about tmpfs here: https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt This has several advantages, mainly: * Performance - much faster read/write access to data in /tmp -- especially if your disk is spinning media -- and if you're on SSD, this feature extends the life of your flash by reducing your NAND flash writes + - especially if your disk is spinning media + - and if you're on SSD, this feature extends the life of your flash by reducing your NAND flash writes * Security - sensitive data would be cleared from memory on boot, rather than written (leaked) to disk -- important for encryption scenarios * Power consumption - storing information in memory is more energy efficient than reading and writing to disk In scenarios where more space in /tmp is needed than available, one can compliment that tmpfs with 'sudo apt-get install swapspace' which will dynamically create/delete swapfile as necessary. See: http://manpg.es/swapspace -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
** Description changed: In Ubuntu, we have always cleared /tmp on every boot. As such, on servers, by default /tmp should actually be a tmpfs entirely in RAM, when there is enough memory in the system. This threshold should be configurable by the end user (in cloud-init?), and default threshold of ~2GB. Read about tmpfs here: https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt This has several advantages, mainly: * Performance - much faster read/write access to data in /tmp +- especially if your disk is spinning media +- and if you're on SSD, this feature extends the life of your flash by reducing your NAND flash writes * Security - sensitive data would be cleared from memory on boot, rather than written (leaked) to disk -- important for encryption scenarios * Power consumption - storing information in memory is more energy efficient than reading and writing to disk In scenarios where more space in /tmp is needed than available, one can compliment that tmpfs with 'sudo apt-get install swapspace' which will - dynamically create/delete swapfile as necessary. + dynamically create/delete swapfile as necessary. See: + http://manpg.es/swapspace -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
** Description changed: - In Ubuntu, we clear /tmp on every boot. + In Ubuntu, we have always cleared /tmp on every boot. As such, on servers, by default /tmp should actually be a tmpfs entirely in RAM, when there is enough memory in the system. This threshold should be configurable by the end user (in cloud-init?), and default threshold of ~2GB. + + Read about tmpfs here: + https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt This has several advantages, mainly: * 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 * Power consumption - storing information in memory is more energy efficient than reading and writing to disk In scenarios where more space in /tmp is needed than available, one can compliment that tmpfs with 'sudo apt-get install swapspace' which will dynamically create/delete swapfile as necessary. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
** Description changed: In Ubuntu, we clear /tmp on every boot. As such, on servers, by default /tmp should actually be a tmpfs entirely - in RAM. + in RAM, when there is enough memory in the system. This threshold + should be configurable by the end user (in cloud-init?), and default + threshold of ~2GB. This has several advantages, mainly: * 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 * Power consumption - storing information in memory is more energy efficient than reading and writing to disk In scenarios where more space in /tmp is needed than available, one can compliment that tmpfs with 'sudo apt-get install swapspace' which will dynamically create/delete swapfile as necessary. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
** Description changed: In Ubuntu, we clear /tmp on every boot. As such, on servers, by default /tmp should actually be a tmpfs entirely in RAM. This has several advantages, mainly: - * 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 + * 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 + * Power consumption - storing information in memory is more energy efficient than reading and writing to disk ** Description changed: In Ubuntu, we clear /tmp on every boot. As such, on servers, by default /tmp should actually be a tmpfs entirely in RAM. This has several advantages, mainly: * 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 - * Power consumption - storing information in memory is more energy efficient than reading and writing to disk + * Power consumption - storing information in memory is more energy efficient than reading and writing to disk + + In scenarios where more space in /tmp is needed than available, one can + compliment that tmpfs with 'sudo apt-get install swapspace' which will + dynamically create/delete swapfile as necessary. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
This doesn't sound like a good idea to me, given the prevalence of running Ubuntu on virtual machines with less than 4GB of RAM. I'm thinking specifically of hosting providers like Linode, AWS, DigitalOcean, etc., as well as tools like Vagrant, all of which are extremely popular right now. Using tmpfs on a machine with so little RAM doesn't sound like it will really help performance because the gain in speed accessing /tmp is offset by having to swap to disk. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
Can we publish some test images? Instead of guessing at this, we can benchmark this. In general swapping ram-based for what is almost always disk-based is going to impact applications/deployments using tmp and expecting enough space there. It's not uncommon for large ISO or other image downloads to reside in this location and this change would break smaller instances which are memory constrained from doing these sorts of tasks without changing where things are stored. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
> The big disadvantage of a tmpfs /tmp is that it cannot be paged out My mistake, this is untrue if you have swap enabled (and enough swap available). I was thinking of ramfs. I still wonder what any performance gain would be, though. Using tmpfs will still limit size to available RAM + available swap space. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
I'd also add that the cloud image build process isn't the right place to make such a change, I don't think. It should be cloud-init or some system boot script that is shipped by a package in the archive. -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
> and then killing the system due to memory starvation Actually I think tmpfs is limited to 50% of system RAM or something by default, but that brings up another issue. By doing this we're severely limiting the available disk in /tmp. Or does that not matter in the cloud image case because / is expected to be smaller than 50% of RAM anyway? -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
[Bug 1533639] Re: [ubuntu-cpc] please make /tmp a tmpfs in RAM
> * Performance - much faster read/write access to data in /tmp Is this really true? Writes to /tmp will go to the page cache, which I believe is an identical path whether /tmp is backed by disk or by tmpfs. Similarly reads from /tmp will come from the page cache except where pages have been evicted in the case of a disk-backed /tmp, which cannot happen with tmpfs. fsyncs on /tmp will be slower. Whether that's a problem depends on the application. But do we need to use tmpfs to eliminate that? Is there a better way of just swallowing syncs (eatmydata style), which would have the same effect? The big disadvantage of a tmpfs /tmp is that it cannot be paged out, and thus puts pressure on available system RAM. One failure case is a sysadmin expecting it to be backed to disk (and therefore be big), using it for something temporary, and then killing the system due to memory starvation. > * Security - sensitive data would be cleared from memory on boot, rather than written (leaked) to disk -- important for encryption scenarios If this is important then surely the user is encrypting the filesystem on disk anyway? -- You received this bug notification because you are a member of Ubuntu Server Team, which is subscribed to the bug report. https://bugs.launchpad.net/bugs/1533639 Title: [ubuntu-cpc] please make /tmp a tmpfs in RAM To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/livecd-rootfs/+bug/1533639/+subscriptions -- Ubuntu-server-bugs mailing list Ubuntu-server-bugs@lists.ubuntu.com Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-server-bugs
