Thanks for the information. I had forgotten some of the Linux terms, such as swap file or partition. How do I go about setting up a tmpfs? The installation will be command-line only Braille only Debian. I might add a desktop later, but I don't want it to be automatically loaded at boot time. What CPU would be appropriae. I would guess something recent, but not the latest. Thanks, John On Sat, Jul 16, 2016 at 02:06:45PM -0400, Sam Hartman wrote: > >>>>> "John" == John J Boyer <john.boyer@xxxxxxxxxxxxxxxxx> writes: > > John> I've more or less decided to replacer my ten-year-old Linux > John> machine. It is giving error messages intermittently. Most of > John> them are about sector errors, but others seem to have nothing > John> to do with the hard drive. It may be more and more > John> troublesome, even if the hard drive is replaced. Besides, it > John> would be nice to get more up-to-date hardware. > > John> I'm thinking of getting 32 GB of ram. 8 GB will be for normal > John> use. The other 24 GB will be in a ramdisk. > > I think you must have a DOS background here. > An explicit RAM disk is rarely if ever useful on Linux. I'm tryinfg to > remember if I even know how to create a block device backed by RAM... O, > yeah, I can think of a way, but you probably don't want to do that. > > Instead, you probably do want to create something called a tmpfs. > That's a filesystem backed by RAM. When your computer reboots all its > contents go away. > > There are important differences between a tmpfs and a RAM disk. > The biggest is that Linux will only use as much RAM as is needed by the > tmpfs to store what currently lives in it. > (You can set a maximum size, but with 32g I wouldn't bother) > > So, you can get the best of both worlds, storing your temporary files in > RAM, but using RAM for RAM if you don't have 24G of temporary files at > the moment. > > > John> Do I need a paging > John> file? 8 GB of available ram should be more than enough. The > John> paging file on my present machine always shows 0 usage, even > John> with only 4 GB of ram. > > > Having a paging file has a couple of affects even if it is not used, but > no, you probably don't want a swap partition or file (linux names for > paging) > > John> How do I avoid setting up a paging file > John> during installation? I'm using Debian Jessie. > > In expert mode, avoid creating a swap partition and if asked don't > create a swap file. > If you don't want to use expert mode, don't worry about it; having a > swap partition won't be a problem. > > John> How do i set up the ramdisk? I want to assign the temp > John> directory to it. > > I think the installer will do that by default. > But in /etc/fstab you want a line like > > none /tmp tmpfs defaults 0 0 > > John> It might be nice if the > John> bin, sbin and usr > John> directories were loaded onto it at boot-up. > > No need for that. > Linux is also smart enough to cache files as they are used, storing > copies in memory, so no value in moving them to the tmpfs. > > The file will be loaded the first time it is used. > You could do that at boot for /bin, /sbin and /usr, but you probably > don't want to. The reason is that the system is fairly busy at boot, > and it would probably slow down things like bringing up your desktop and > starting system services. The only advantage of pre-caching files on > boot would be faster performance the first time you accessed a program > after pre-caching is done. However you get slower boot times and slower > performance during the pre-caching. -- John J. Boyer; President, AbilitiesSoft, Inc. Email: john.boyer@xxxxxxxxxxxxxxxxx Website: http://www.abilitiessoft.org Status: 501(C)(3) Nonprofit Location: Madison, Wisconsin USA Mission: To develop softwares and provide STEM services for people with disabilities which are available at no cost. _______________________________________________ Blinux-list mailing list Blinux-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/blinux-list