We all know...
nice -n19
for low CPU priority.
ionice -c3
for low I/O priority.
nocache can be useful in related scenarios, when we operate on very large files just a single time, e.g. a backup job. It advises the kernel that no caching is required for the involved files, so our current file cache is not erased, potentially decreasing performance on other, more typical file I/O, e.g. on a desktop.
http://askubuntu.com/questions/122857
https://github.com/Feh/nocache
http://packages.debian.org/search?keywords=nocache
http://packages.ubuntu.com/search?keywords=nocache
To undo caching of a single file in hindsight, you can do
cachedel <OneSingleFile>
To check the cache status of a file, do
cachestats <OneSingleFile>
Found here: http://ubuntuforums.org/showthread.php?t=589975
Best result when file size less than half of RAM size
Ever gone to a site that has an MP3 embedded into a pesky flash player, but no download link? Well, this one-liner will yank the names of those tunes straight out of FF's cache in a nice, easy to read list. What you do with them after that is *ahem* no concern of mine. ;) Show Sample Output
Grab a list of MP3s (with full path) out of Firefox's cache Ever gone to a site that has an MP3 embedded into a pesky flash player, but no download link? Well, this one-liner will yank the *full path* of those tunes straight out of FF's cache in a clean list. Shorter and Intuitive version of the command submitted by (TuxOtaku) Show Sample Output
Occasionally, to force zone updating, cache flush is necessary. The use of this command is better than restart the Bind9 process.
Occasionally, to force zone updating, cache flush is necessary. This command is better than restart the mydns daemon.
"That's it. Not much to see here. The first command writes any cache data that hasn't been written to the disk out to the disk. The second command tells the kernel to drop what's cached. Not much to it. This invalidates the write cache as well as the read cache, which is why we have the sync command first. Supposedly, it is possible to have some cached write data never make it to disk, so use it with caution, and NEVER do it on a production server. You could ... but why take the risk? As long as you are running a post 2.6.16 kernel,..." Source: http://ubuntuforums.org/showpost.php?p=3621283&postcount=1
Clear Cached Memory on Ubuntu based distributions, and also display memory status. Please do not use this on a production machine unless you really really know what you are doing. Echo 3 is a kinder way of purging the memory, you can also use 'echo 2' or 'echo 1' if #1 You know what you are doing, and #2 refer to number 1 :-)
commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.
Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.
» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10
Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):
Subscribe to the feed for: