[CentOS] why i can not put my swap files in /dev?
I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? -- Tang Jianwei ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
2010/7/6 Tang Jianwei myh...@gmail.com: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. /dev/* is virtual directory containing all devices, not files. create your swap on disk devices (/dev/sdXX, not in empty space) -- Eero, RHCE ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
On 07/06/2010 12:41 PM, Tang Jianwei wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. Does the file exist after reboot? I think the /dev directory is made in a RAM disk (tmpfs), not a useful place to put a swapfile. Mogens -- Mogens Kjaer, m...@lemo.dk http://www.lemo.dk ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
Thank you and Mogens. and I also think this is the cause. Tang Jianwei On 07/06/2010 06:50 PM, Eero Volotinen wrote: /dev/* is virtual directory containing all devices, not files. create your swap on disk devices (/dev/sdXX, not in empty space) ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
At Tue, 06 Jul 2010 18:41:06 +0800 CentOS mailing list centos@centos.org wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? /dev is mounted from a *ramdisk* -- swapping to a RAM disk makes really no sense. With a modern (eg 2.6 kernel w/udev), /dev is created fresh at boot time and only contains device node files, generally created on-the-fly by udevd. -- Robert Heller -- Get the Deepwoods Software FireFox Toolbar! Deepwoods Software-- Linux Installation and Administration http://www.deepsoft.com/ -- Web Hosting, with CGI and Database hel...@deepsoft.com -- Contract Programming: C/C++, Tcl/Tk ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
On Tue, Jul 06, 2010 at 06:41:06PM +0800, Tang Jianwei wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? /dev is not a real directory for data files. You should actually make a separate partition for swap Otherwise, you can put it in some real file spaca such as in /usr or where you left a lot of space.That is often done to increase available swap space when the originally created swap partition is not large enough - add some from file space. jerry -- Tang Jianwei ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
Jerry McAllister wrote: On Tue, Jul 06, 2010 at 06:41:06PM +0800, Tang Jianwei wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? Well, /dev is *not* a good place for anything but device files. /dev is not a real directory for data files. snip Um, er, what do you mean about it not being a real directory? mark -- When I hear about object oriented systems, I think of one that's been around for about 40 years: *Nix. Everything's a file, er, object, and you pipe, er, message from one object to another ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
In the past I only heard that /proc and /sys are RAM directories, now I get /dev as well. thank you. Tang Jianwei On 07/06/2010 10:14 PM, John Kennedy wrote: On Tue, Jul 6, 2010 at 10:01 AM, m.r...@5-cent.us mailto:m.r...@5-cent.us wrote: Jerry McAllister wrote: On Tue, Jul 06, 2010 at 06:41:06PM +0800, Tang Jianwei wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? Well, /dev is *not* a good place for anything but device files. /dev is not a real directory for data files. snip Um, er, what do you mean about it not being a real directory? mark I would say he means real as exists on a hard drive like /home of /var as opposed to virtual as exists in RAM like /proc. John -- John Kennedy ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
At Tue, 6 Jul 2010 10:01:10 -0400 CentOS mailing list centos@centos.org wrote: Jerry McAllister wrote: On Tue, Jul 06, 2010 at 06:41:06PM +0800, Tang Jianwei wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? Well, /dev is *not* a good place for anything but device files. /dev is not a real directory for data files. snip Um, er, what do you mean about it not being a real directory? It is not 'persistent' across boots. It is not backed by actual hard disk space. Any *data* files (including swap files) will be gone at the next reboot. The *device* files are re-created by udevd during the boot process (and later on by the hotplug / HAL subsystem). mark -- When I hear about object oriented systems, I think of one that's been around for about 40 years: *Nix. Everything's a file, er, object, and you pipe, er, message from one object to another ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos -- Robert Heller -- 978-544-6933 Deepwoods Software-- Download the Model Railroad System http://www.deepsoft.com/ -- Binaries for Linux and MS-Windows hel...@deepsoft.com -- http://www.deepsoft.com/ModelRailroadSystem/ ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
On Tue, Jul 06, 2010 at 10:14:19AM -0400, John Kennedy wrote: On Tue, Jul 6, 2010 at 10:01 AM, m.r...@5-cent.us wrote: Jerry McAllister wrote: On Tue, Jul 06, 2010 at 06:41:06PM +0800, Tang Jianwei wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? Well, /dev is *not* a good place for anything but device files. /dev is not a real directory for data files. snip Um, er, what do you mean about it not being a real directory? mark I would say he means real as exists on a hard drive like /home of /var as opposed to virtual as exists in RAM like /proc. John Yup. jerry -- John Kennedy ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
Re: [CentOS] why i can not put my swap files in /dev?
At Tue, 06 Jul 2010 22:30:10 +0800 CentOS mailing list centos@centos.org wrote: In the past I only heard that /proc and /sys are RAM directories, now /proc and /sys are psuedo directories -- they hook into kernel data structures. I get /dev as well. thank you. With 2.6 kernels and udev, /dev has become a RAMDISK that is freshly populated at boot time by udevd and related code (HAL and the hotplug system). Tang Jianwei On 07/06/2010 10:14 PM, John Kennedy wrote: On Tue, Jul 6, 2010 at 10:01 AM, m.r...@5-cent.us mailto:m.r...@5-cent.us wrote: Jerry McAllister wrote: On Tue, Jul 06, 2010 at 06:41:06PM +0800, Tang Jianwei wrote: I tried to create some swap files in /dev directory for my desktop. the dd and mkswap were ok. but when I try to swapon it, i get this: # swapon /dev/myswap swapon: /dev/myswap: Invalid argument but when I mv the file to some other directory like /mnt or /, the swapon works. could sb. tell me why? Well, /dev is *not* a good place for anything but device files. /dev is not a real directory for data files. snip Um, er, what do you mean about it not being a real directory? mark I would say he means real as exists on a hard drive like /home of /var as opposed to virtual as exists in RAM like /proc. John -- John Kennedy ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos MIME-Version: 1.0 ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos -- Robert Heller -- 978-544-6933 Deepwoods Software-- Download the Model Railroad System http://www.deepsoft.com/ -- Binaries for Linux and MS-Windows hel...@deepsoft.com -- http://www.deepsoft.com/ModelRailroadSystem/ ___ CentOS mailing list CentOS@centos.org http://lists.centos.org/mailman/listinfo/centos
