- It might be advantageous to reduce the amount of swap space to 1 GB, since the larger 2 GB could be wasting disk space. You have three options: remove an entire LVM2 logical volume used for swap, remove a swap file, or reduce swap space on an existing LVM2 logical volume.
- It has a very clean and simple interface with options to set memory size to be freed and free RAM. You can view the total free memory, so that you can manually boost RAM whenever required. An option available frees up RAM automatically whenever free memory goes below 5MB.
- Here “sync” will clear the file system buffer, “dropcache” will clean cache without killing any other application or service and “.echo 2.” will clear PageCache as well as Dentries and Inodes. Clear Swap Space in Linux: To Clear Swap Space in Linux you should run the following command.
- Right click the Windows task bar and select Task Manager. Click on the Processes tab. Sort the processes by Memory and look for programs at the top of the list that you don’t recognize. If you spot any problem applications, go into the Control Panel, click on Programs and Features, and uninstall those problem applications.
Clearing RAM Memory Cache, Buffer and Swap Space on Linux. Memory management like Clear RAM Memory Cache, Buffer and Swap Space in Linux will be discussed in this article. To Clear Cache in Linux. Generally all the Linux System will have three options to clear cache without interrupting any services or processes.
Like any other operating system, GNU/Linux has implemented a memory management efficiently and even more than that. But if any process is eating away your memory and you want to clear it, Linux provides a way to flush or clear ram cache.
How to Clear Cache in Linux?
Every Linux System has three options to clear cache without interrupting any processes or services.
1. Clear PageCache only.
2. Clear dentries and inodes.
3. Clear PageCache, dentries and inodes.
Explanation of above command.
sync will flush the file system buffer. Command Separated by “;” run sequentially. The shell wait for each command to terminate before executing the next command in the sequence. As mentioned in kernel documentation, writing to drop_cache will clean cache without killing any application/service, command echo is doing the job of writing to file.
If you have to clear the disk cache, the first command is safest in enterprise and production as “...echo 1 > ….” will clear the PageCache only. It is not recommended to use third option above “...echo 3 >” in production until you know what you are doing, as it will clear PageCache, dentries and inodes.
Is it a good idea to free Buffer and Cache in Linux that might be used by Linux Kernel?
When you are applying various settings and want to check, if it is actually implemented specially on I/O-extensive benchmark, then you may need to clear buffer cache. You can drop cache as explained above without rebooting the System i.e., no downtime required.
Linux is designed in such a way that it looks into disk cache before looking onto the disk. If it finds the resource in the cache, then the request doesn’t reach the disk. If we clean the cache, the disk cache will be less useful as the OS will look for the resource on the disk.
Moreover it will also slow the system for a few seconds while the cache is cleaned and every resource required by OS is loaded again in the disk-cache.
Clear Swap Memory Centos
Now we will be creating a shell script to auto clear RAM cache daily at 2am via a cron scheduler task. Create a shell script clearcache.sh and add the following lines.
Set execute permission on the clearcache.sh file.
Now you may call the script whenever you required to clear ram cache.
Now set a cron to clear RAM cache everyday at 2am. Open crontab for editing.
Append the below line, save and exit to run it at 2am daily.
Clear Swap Memory Windows
For more details on how to cron a job you may like to check our article on 11 Cron Scheduling Jobs.
Is it good idea to auto clear RAM cache on production server?
No! it is not. Think of a situation when you have scheduled the script to clear ram cache everyday at 2am. Everyday at 2am the script is executed and it flushes your RAM cache. One day for whatsoever reason, may be more than expected users are online on your website and seeking resource from your server.
Clean Swap Memory Card
At the same time scheduled script run and clears everything in cache. Now all the user are fetching data from disk. It will result in server crash and corrupt the database. So clear ram-cache only when required,and known your foot steps, else you are a Cargo Cult System Administrator.
How to Clear Swap Space in Linux?
If you want to clear Swap space, you may like to run the below command.
Also you may add above command to a cron script above, after understanding all the associated risk.
Now we will be combining both above commands into one single command to make a proper script to clear RAM Cache and Swap Space.
Clean Swap Memory Foam
After testing both above command, we will run command “free -h” before and after running the script and will check cache.