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| dcore:swap_partition_or_file [2016/08/09 02:08] – [Swap Overview] nitram | dcore:swap_partition_or_file [2017/09/17 09:20] (current) – internal links corrected sm8ps |
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| ===== dCore Swap Partition or Swap File ===== | ===== dCore Swap ===== |
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| ==== Swap Overview ==== | ==== Overview ==== |
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| A swap primer for dCore users with minimal Linux or no Tiny Core Linux experience. | A swap primer for dCore users with minimal Linux or Tiny Core Linux experience. |
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| Depending on intended use, a [[https://www.linux.com/news/all-about-linux-swap-space|Linux swap partition or swap file]] is recommended for systems with < 1-2 GB RAM. Swap is especially useful on low RAM systems to import/update large extensions, run numerous/heavier applications, compile software or set up hibernation. | Depending on intended use, a [[https://www.linux.com/news/all-about-linux-swap-space|Linux swap partition or swap file]] is recommended for systems with < 1-2 GB RAM. Swap is especially useful on low RAM systems to import/update large extensions, run numerous/heavier applications, compile software or set up hibernation. |
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| By default, dCore will seek and utilize any existing swap partition at boot. To confirm whether a swap partition is being utilized, run ''cat /etc/fstab'', ''free -m'' and/or ''cat /proc/swaps'', examples: | By default, dCore will seek and utilize any existing swap partition at boot. It also by default utilizes [[https://en.wikipedia.org/wiki/Zswap|zswap]] at boot. A boot code is necessary to enable a previously set up swap file. Review the swap related [[dCore:swap_partition_or_file#boot_codes|boot codes]] below for more information related to enabling a swap file or disabling swap and zswap. |
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| | The following commands are useful to confirm swap utilization: |
| | cat /etc/fstab |
| | cat /proc/swaps |
| | dmesg | grep swap |
| | free -m |
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| | Example outputs outlined below utilizing a system with 512 MB RAM, 729 MB swap partition plus zswap. Note total swap indicated by ''free -m'' includes all available swap (eg. swap partition + zswap). |
| <code> | <code> |
| tc@box:~$ cat /etc/fstab | grep swap | tc@box:~$ cat /etc/fstab | grep swap |
| /dev/sda5 none swap defaults 0 0 # Added by TC | /dev/zram0 swap swap defaults,noauto 0 0 |
| | /dev/sda5 none swap defaults 0 0 |
| </code> | </code> |
| <code> | <code> |
| tc@box:~$ free -m | tc@box:~$ cat /proc/swaps |
| total used free shared buffers cached | Filename Type Size Used Priority |
| Mem: 500 484 15 73 37 267 | /dev/zram0 partition 116524 5224 -1 |
| -/+ buffers/cache: 179 320 | /dev/sda5 partition 746984 0 -2 |
| Swap: 729 1 727 | |
| </code> | </code> |
| <code> | <code> |
| tc@box:~$ cat /proc/swaps | tc@box:~$ dmesg | grep swap |
| Filename Type Size Used Priority | [ 2.968436] Adding 116524k swap on /dev/zram0. Priority:-1 extents:1 across:116524k SSFS |
| /dev/sda5 partition 746984 0 -1 | [ 10.644207] Adding 746984k swap on /dev/sda5. Priority:-2 extents:1 across:746984k FS |
| </code> | </code> |
| | <code> |
| | tc@box:~$ free -m |
| | total used free shared buffers cached |
| | Mem: 500 484 15 80 62 233 |
| | -/+ buffers/cache: 188 311 |
| | Swap: 843 5 838 |
| | </code> |
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| | ==== Swap Partition ==== |
| | Setting up a swap partition during a fresh installation using [[http://tldp.org/HOWTO/Partition/fdisk_partitioning.html|fdisk]] is outlined in the [[dCore:installation_from_iso_without_boot_loader#partition_hard_drive|Partition Hard Drive]] and [[dCore:installation_from_iso_without_boot_loader#create_hard_drive_file_systems|Create Hard Drive File Systems]] sections of [[dCore:installation_from_ISO_without_boot_loader|dCore Install from ISO to Hard Drive Without Pre-Existing Boot Loader]]. For systems with a pre-partitioned drive, it may be easier to use a [[https://livecdlist.com/|Linux LiveCD]] that contains [[http://gparted.org/|GParted]]. Alternatively set up a swap file, outlined below. To confirm the swap partition is being used, reboot system and run the commands outlined above. |
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| | ==== Swap File ==== |
| | If a swap partition was not set up prior to the installation of dCore, it would be easiest to set up a swap file rather than create a new swap partition. From a graphic environment open Control Panel (cpanel) -> Swapfile Tool (swapfile) and enter the desired mounted partition to utilize along with the desired swap file size. Then add the [[http://tinycorelinux.net/faq.html#bootcodes|swapfile bootcode]] to the system's boot loader to activate upon reboot, example ''swapfile=sda1''. To confirm the swap file is being used, reboot system and run the commands outlined above. |
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| ==== Swap Partition Install ==== | ==== Boot Codes ==== |
| Setting up a hard drive swap partition during a fresh installation using [[http://tldp.org/HOWTO/Partition/fdisk_partitioning.html|fdisk]] is outlined in the [[http://wiki.tinycorelinux.net/dcore:installation_from_iso_without_boot_loader#partition_hard_drive|Partition Hard Drive]] and [[http://wiki.tinycorelinux.net/dcore:installation_from_iso_without_boot_loader#create_hard_drive_file_systems|Create Hard Drive File Systems]] sections of [[dcore:installation_from_ISO_without_boot_loader|dCore Install from ISO to Hard Drive Without Pre-Existing Boot Loader]]. Systems with a pre-partitioned drive may find it easiest to use a [[https://livecdlist.com/|Linux LiveCD]] that contains [[http://gparted.org/|GParted]] to re-partition a drive and create a swap partition. Alternatively set up a swap file, outlined below. | For more information regarding Tiny Core Linux boot codes review [[wiki:boot_codes_explained|boot codes explained]]. |
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| ==== Swap File Install ==== | The following swap related [[http://distro.ibiblio.org/tinycorelinux/faq.html#bootcodes|boot codes]] are available: |
| If a swap partition was not set up prior to the installation of dCore, it may be easiest to simply set up a swap file. From a graphic environment open Control Panel (cpanel) -> Swapfile Tool (swapfile) and enter the desired mounted partition to utilize along with the desired swap file size. Then add the [[http://tinycorelinux.net/faq.html#bootcodes|swapfile bootcode]] to the systems existing boot loader to activate upon reboot, example ''swapfile=sda1''. To confirm the swap file is being used, upon reboot run ''cat /proc/swaps''. | *swapfile: use the specified partition's swap file (eg. swapfile=sda2). |
| | *noswap: disable use of any swap partition(s) (eg. noswap). |
| | *nozswap: disable zswap (eg. nozswap). |
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| ==== Swap Boot Codes ==== | ==== Miscellaneous ==== |
| The noswap boot code can be used to disable the use of a swap partition at boot. | As outlined, dCore automatically seeks available swap partition(s) at boot. If using the swapfile boot code, a swapfile needs to be set up in advance. By default dCore uses zswap, which sets aside a block of RAM to use as compressed swap space, so systems with adequate RAM may not require dedicated swap. Review the Wikipedia zswap link above for more information, especially the [[https://en.wikipedia.org/wiki/CPU|CPU]] cycles vs [[https://en.wikipedia.org/wiki/I/O|I/O]] tradeoff. Actual system experimentation is recommended to determine which swap options or boot codes are required, if any. This [[http://www.cyberciti.biz/faq/linux-add-a-swap-file-howto/|Linux Swap File How To]] is a valuable resource for manually creating a swap file or experimenting with swappiness. |
| http://forum.tinycorelinux.net/index.php?topic=19421.0 | |
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| **[[http://wiki.tinycorelinux.net/dcore:welcome|> Return to the dCore Wiki Welcome page]]** | **[[dCore:welcome|> Return to the dCore Wiki Welcome page]]** |
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