Linked Questions

15
votes
2answers
122k views

How to clear memory cache in Linux [duplicate]

Is there any command that by using I can clean the cache in RHEL? I used this command: sync; echo 3 > /proc/sys/vm/drop_caches but it didn't work.
9
votes
1answer
7k views

What is equivalent to Mac's purge in Linux? [duplicate]

In Mac I use purge to free up some memory. What is equivalent to it in Linux(Ubuntu Server)? apt-get install purge gave me nothing. If you are no familiar with Mac's purge here is it's man page: ...
0
votes
2answers
483 views

Is there a way to free memory? [duplicate]

I remember, back from my days with Windows Vista/7, that there was a tool called memclear or memclean that would free some memory by invoking the NT garbage collection API. Probably it cleared cache ...
63
votes
5answers
59k views

Does rsync verify files copied between two local drives?

I want to make a fresh new copy of a large number of files from one local drive to another. I've read that rsync does a checksum comparison of files when sending them to a remote machine over a ...
72
votes
1answer
144k views

Setting /proc/sys/vm/drop_caches to clear cache

As part of doing some cold cache timings, I'm trying to free the OS cache. The kernel documentation (retrieved January 2019) says: drop_caches Writing to this will cause the kernel to drop clean ...
38
votes
6answers
3k views

How do I use swap space for emergencies only?

I have a Debian (Buster) laptop with 8 GB RAM and 16GB swap. I'm running a very long running task. This means my laptop has been left on for the past six days while it churns through. While doing ...
11
votes
2answers
3k views

Need something that is faster than “wc -l”

For a really big file like 1GB wc -l happens to be slow. Do we have a faster way calculating the number of newlines for a particular file?
31
votes
2answers
2k views

Why did powering down my machine after a bad `rm` save my files?

Classical situation: I ran a bad rm and realized immediately afterwards that I had removed the wrong files. (Nothing critical and I had tolerably recent backups, but still annoying.) Knowing that ...
17
votes
2answers
8k views

Linux: Total swap used = swap used by processes +?

So, I'm trying to do some investigation on where does swap use come from in a system with high swap usage: # free total used free shared buffers cached Mem: ...
6
votes
1answer
13k views

What does -/+ buffers/cache means in the output of free? [closed]

I know this is a lame question, but I want to understand why CentOS consumes my Physical memory when certain process stopped. Suppose I have opened a file of 10GB then it consumes 10GB in ram and ...
5
votes
2answers
11k views

Memory runs full over time, high “buffer/cache” usage, low “available” memory

Whenever I reboot my laptop, everything runs amazingly and I have a maximum of 40% memory usage (out of 8GB). However over time (~ 1 day of usage), memory usage goes up to 90%+, and the system starts ...
8
votes
1answer
5k views

List all files that are present in the cache

This question answers to the question on how to find the what is part of cache. However, in the fincore executable you have to pass the filename to check if it is part of cache. Is there a tools or a ...
3
votes
3answers
1k views

When is there a need to flush caches in Linux ?

I came across this . And then remembered seeing this something back. Could anybody elaborate is there any need for a user to ever flush the caches or it's only need is when you want to benchmark ...
2
votes
3answers
1k views

Does sync command remove the dirty cache in the memory?

I am aware that sync command flushes the dirty cache into disk. I have run free command first, then sync, and then free again. The result of latter free command shows more free memory available than ...
3
votes
2answers
665 views

Pipe Viewer - Progress monitor performance consequence

I am writing a batch script to sort through gigs and gigs of data. All of the data is text but the script will take a long long time to execute. I would like to give some visual indication that the ...

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