diff --git a/sources/tech/20180328 How To Create-Extend Swap Partition In Linux Using LVM.md b/sources/tech/20180328 How To Create-Extend Swap Partition In Linux Using LVM.md new file mode 100644 index 0000000000..66d3156bf2 --- /dev/null +++ b/sources/tech/20180328 How To Create-Extend Swap Partition In Linux Using LVM.md @@ -0,0 +1,149 @@ +How To Create/Extend Swap Partition In Linux Using LVM +====== +We are using LVM for flexible volume management so, why can’t we use LVM for swap space? + +This allow users to increase the swap partition whenever we need. + +If you upgraded the RAM in your system, it is necessary to add more swap space. + +This help you to manage the system that run applications that require a large amount of memory. + +Swap can be created in three ways + + * Create a new swap partition + * Create a new swap file + * Extend swap on an existing logical volume (LVM) + + + +It’s recommended to create a dedicated swap partition instead of swap file. + +**Suggested Read :** +**(#)** [3 Easy Ways To Create Or Extend Swap Space In Linux][1] +**(#)** [Automatically Create/Remove And Mount Swap File In Linux Using Shell Script][2] + +What is the recommended swap size in Linux? + +### What Is Swap Space + +Swap space in Linux is used when the amount of physical memory (RAM) is full. When physical RAM is full, inactive pages in memory are moved to the swap space. + +This helps system to run the application continuously but it’s not considered a replacement for more RAM. + +Swap space is located on hard drives so, it would not processing the request like physical RAM. + +### How To Create A Swap Partition Using LVM + +As we already know how to create logical volume do the same for swap as well. Just follow the below procedure. + +Create a logical volume which you required. In my case i’m going to create `5GB` of swap partition. +``` +$ sudo lvcreate -L 5G -n LogVol_swap1 vg00 + Logical volume "LogVol_swap1" created. + +``` + +Format the new swap space. +``` +$ sudo mkswap /dev/vg00/LogVol_swap1 +Setting up swapspace version 1, size = 5 GiB (5368705024 bytes) +no label, UUID=d278e9d6-4c37-4cb0-83e5-2745ca708582 + +``` + +Add the following entry to the `/etc/fstab` file. +``` +# vi /etc/fstab +/dev/mapper/vg00-LogVol_swap1 swap swap defaults 0 0 + +``` + +Enable the extended logical volume. +``` +$ sudo swapon -va +swapon: /swapfile: already active -- ignored +swapon: /dev/mapper/vg00-LogVol_swap1: found signature [pagesize=4096, signature=swap] +swapon: /dev/mapper/vg00-LogVol_swap1: pagesize=4096, swapsize=5368709120, devsize=5368709120 +swapon /dev/mapper/vg00-LogVol_swap1 + +``` + +Test that the swap space has been added properly. +``` +$ cat /proc/swaps +Filename Type Size Used Priority +/swapfile file 1459804 526336 -1 +/dev/dm-0 partition 5242876 0 -2 + +$ free -g + total used free shared buff/cache available +Mem: 1 1 0 0 0 0 +Swap: 6 0 6 + +``` + +### How To Expand A Swap Partition Using LVM + +Just follow the below procedure to extend an LVM swap logical volume. + +Disable swapping for the associated logical volume. +``` +$ sudo swapoff -v /dev/vg00/LogVol_swap1 +swapoff /dev/vg00/LogVol_swap1 + +``` + +Resize the logical volume. I’m going to increase the swap volume from `5GB to 11GB`. +``` +$ sudo lvresize /dev/vg00/LogVol_swap1 -L +6G + Size of logical volume vg00/LogVol_swap1 changed from 5.00 GiB (1280 extents) to 11.00 GiB (2816 extents). + Logical volume vg00/LogVol_swap1 successfully resized. + +``` + +Format the new swap space. +``` +$ sudo mkswap /dev/vg00/LogVol_swap1 +mkswap: /dev/vg00/LogVol_swap1: warning: wiping old swap signature. +Setting up swapspace version 1, size = 11 GiB (11811155968 bytes) +no label, UUID=2e3b2ee0-ad0b-402c-bd12-5a9431b73623 + +``` + +Enable the extended logical volume. +``` +$ sudo swapon -va +swapon: /swapfile: already active -- ignored +swapon: /dev/mapper/vg00-LogVol_swap1: found signature [pagesize=4096, signature=swap] +swapon: /dev/mapper/vg00-LogVol_swap1: pagesize=4096, swapsize=11811160064, devsize=11811160064 +swapon /dev/mapper/vg00-LogVol_swap1 + +``` + +Test that the logical volume has been extended properly. +``` +$ free -g + total used free shared buff/cache available +Mem: 1 1 0 0 0 0 +Swap: 12 0 12 + +$ cat /proc/swaps +Filename Type Size Used Priority +/swapfile file 1459804 237024 -1 +/dev/dm-0 partition 11534332 0 -2 + +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/how-to-create-extend-swap-partition-in-linux-using-lvm/ + +作者:[Ramya Nuvvula][a] +译者:[译者ID](https://github.com/译者ID) +校对:[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译,[Linux中国](https://linux.cn/) 荣誉推出 + +[a]:https://www.2daygeek.com/author/ramya/ +[1]:https://www.2daygeek.com/add-extend-increase-swap-space-memory-file-partition-linux/ +[2]:https://www.2daygeek.com/shell-script-create-add-extend-swap-space-linux/