a cache stores temporary data nearby so that it can be retrieved much more quickly than fetching it from the real backing store (disk, network), or recalculating some result all over again

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78
votes
4answers
63k views

Is it okay to delete ~/.cache?

When I use disk usage analyzer and scan my home folder .cache always shows up with a decent bit of things in it. Would it be okay for me to delete the contents of this folder or would it damage ...
74
votes
5answers
27k views

Drawbacks of using preload? Why isn't it included by default?

I would like to know what are the drawbacks of using preload? If there would be no downside, preload would be enabled by default, so I guess there are some. Okay you need a bit more RAM, but most ...
50
votes
4answers
29k views

How do I install and use flashcache/bcache to cache HDD to SSD?

I want to know if there is anyone who has tried installing and running their kernel built with flashcache or bcache for SSD caching? How did you manage to do it?
30
votes
4answers
72k views

How do I clean or disable the memory cache?

After the system starts, in a few minutes my memory cache fills up and it starts using the swap. Here's a screenshot of /proc/meminfo. However, if I can disable this process / clean the cache once ...
27
votes
3answers
13k views

What is safe to exclude for a full system backup?

I'm looking for a list which paths/files are safe to exclude for a full system/home backup. Considering that I have a list of installed packages. /home/*/.thumbnails /home/*/.cache /home/*/....
26
votes
4answers
14k views

Computer freezing on almost full RAM, possibly disk cache problem

The problem I think is somewhat similar to this thread. It doesn't matter if I have swap enabled or disabled, whenever the real used RAM amount starts going close to maximum and there is almost no ...
16
votes
3answers
16k views

How to clean var/cache/apt in a way that it leaves only the latest versions of each package

I want to know a way to clean the var/cache/apt folder in a way that it only leaves the latest version of a package if it has several versions or it leaves a package if it is the only one of that ...
15
votes
2answers
15k views

How do I reset the thumbnail cache?

I have a lot of images on my laptop as I work in graphics. On the same system, I also have a folder containing my family pictures. I would like to do two things: Empty the already cached images ...
15
votes
2answers
8k views

Can I copy large files faster without using the file cache?

After adding the preload package, my applications seem to speed up but if I copy a large file, the file cache grows by more than double the size of the file. By transferring a single 3-4 GB ...
14
votes
6answers
38k views

Best way to set up DNS caching?

In order to speed up DNS lookups, I want to install a DNS cache or proxy. I can see at least three programs I think will do the job: bind9, pdnsd, or dnsmasq. I would like to make sure that if I ...
12
votes
6answers
24k views

Errors in dmesg - Test WP failed, assume Write Enabled [duplicate]

I'm experiencing some problems with drive cache and I don't know what's causing these problems. This is my dmesg: [11690.011238] sd 6:0:0:0: [sdb] Asking for cache data failed [11690.011248] sd 6:0:0:...
10
votes
3answers
28k views

Why is the cache in my memory always full?

I have 6GB RAM, i5 2.4GHZ Processor running Ubuntu 11.10. I partitioned my HD so that I have 8GB swap. When streaming online or opening several tabs in Chromium I soon have 4GB Memory in the cache. ...
10
votes
2answers
7k views

How can I clear my cached gpg password?

I've tried: the SIGHUP method --> no succes the cache timeout in gpg-agent.conf --> it seems that this file is not read, althougt I have the 'use-agent' line in gpg.conf What should I do ?
10
votes
3answers
8k views

How to clean caches in my homedir

My home directory is getting huge (100GB plus). When backupping it I notices that there are quite some caches there. Which important caches are there in my homedir and how should I clean them? One ...
10
votes
2answers
27k views

How do I correctly enable PHP 5.5's OPCache in Ubuntu 14.04?

I'm setting up a local server to test configurations; it's a clean 14.04 LAMP server, as selected during OS install. If I understand correctly, OPCache comes with PHP 5.5 (php -v confirms this) but ...
9
votes
3answers
1k views

Would there be any negative side-effects of sharing /var/cache/apt/ between two systems?

In the interest of conserving bandwidth, I'm considering mounting a VirtualBox host's /var/cache/apt as /var/cache/apt in the guest. Both host and guest are Ubuntu 10.10 32-bit. Would there be any ...
9
votes
3answers
22k views

How do I increase cache size in Chrome?

is there any way to increase the cache size of google chrome in ubuntu 11.10 so that frequently visited pages load faster, im using a very-slow internet connection so i badly need this
9
votes
3answers
1k views

How to add packages to a squid-deb-proxy cache?

To save bandwidth and data on my Internet plan, I have installed squid-deb-proxy on a desktop, and the client on it and a few other machines I've got. However, based on the post that put me onto this ,...
8
votes
3answers
2k views

Why does /var/cache/apt/archives keep deleting files

I normally download all .deb packages and just copy the packages from /var/cache/apt/archives directory to the rest of the computers, saving me to have to download all the updates and programs again. ...
8
votes
1answer
5k views

How to move the user cache directory [~/.cache] out of the /home directory to another partition

The .cache directory is full of volatile, non-essential files. I would like to move it to a more appropriate partition, i.e. faster and not backed up. I believe that ~/.pam_environment file is ...
8
votes
1answer
6k views

What is icon-theme.cache?

When I run the following command on my Lubuntu 12.10 [11:09 PM] ~ $ find /usr/share/icons/ -iname icon-theme.cache -type f I get the following (after adding the last modified date and size): /usr/...
7
votes
3answers
4k views

How do I tell what type of CPU cache is in my laptop?

Is there an application for Ubuntu that could tell me details about CPU, CPU cache memory, memory hierarchy, cache architecture implemented in my system, cpu cache size, cpu cache, access cycle and ...
7
votes
1answer
7k views

What Does Cached Memory Mean when Viewing htop?

While viewing the reports of htop, I would like to know what the orange/brown 'cached memory' bars actually indicate. Really I'm looking for a more practical explanation of what I'm looking at, rather ...
7
votes
2answers
263 views

Does Ubuntu store data of external media/drives?

I keep confidential data (docs, spreadsheets, images, etc) on USB sticks or discs. I plug/insert them to access the data when I need, and put them back in a drawer when I'm done. Does Ubuntu store ...
7
votes
2answers
3k views

How to make ubuntu use more RAM to cache a specific set of binaries?

After 2 weeks of trying, failing, trying again, still failing, I finally got Ubuntu stable and operational. My hard disk is quite old and slow but I have excessive RAM (16 GB 2133 mhz), so I was ...
7
votes
2answers
874 views

Get flash drive to cache disk reads to primary partition

Basically I'm looking for a way to mimic Windows' ReadyBoost. I asked this question on Unix.SE to get an idea of whether this was even possible and it seems like it is. Appparently there is a cachefs ...
6
votes
3answers
4k views

How can I disable the prefetch cache?

I run a few Ubuntu servers that have a load of django sites running on them. The sites and the httpd start at boot and after that (apart from me SSHing in to update it or using bzr to update websites) ...
6
votes
1answer
698 views

Does dnscache really improve the surfing speed?

I have installed dnscache (dnscache-run) from Ubuntu repositories and I have increased the CACHESIZE and DATALIMIT to 256MB (268435456). Today I have tested it with one domain: google.es. I have ...
6
votes
2answers
702 views

Tell the kernel to strongly cache a particular directory

This question is a rephrasing of Optimizing EXT4 performance. I have a directory that contains build files, most very small, but totaling 5.6G. I usually access the same subset of files (some ...
6
votes
1answer
470 views

Disable filesystem read cache

How can I disable the Linux file system read cache for Ubuntu 12.04? I don't want to only free the actual cache. echo 3 > /proc/sys/vm/drop_caches but disable the read cache completely.
5
votes
2answers
46k views

How to clean /var/cache?

When I woke up this morning, I found my root had filled overnight du -hx --max-depth=1 / 132M /boot 4.0K /media 16K /lost+found 16M /root 702M /lib 4.0K /OLDHOME 8.2G /usr ...
5
votes
2answers
2k views

Can an external flash or hard drive be used to boost performance, similar to Windows' ReadyBoost?

I have a number of spare external hard disk drives lying about the place and I was wondering if there is any practical way of using an external hard drive or USB flash memory drive to boost ...
5
votes
1answer
2k views

Retrieve Google Chrome Ubuntu favicon

Where the favicon .ico file is stored in Ubuntu 11.10? How can I extract the .ico file from the chrome cache?
5
votes
1answer
808 views

How to preload programs?

What I want to do is open some programs in the boot sequence so Ubuntu loads them into memory. I'm already using the preload package and it's not helping in that part. Thanks.
5
votes
2answers
3k views

Install deb package with all dependencies in same folder?

I need to install multiple deb files of same software from apt cache in another ubuntu installation. For example, I have all deb files of vlc in same folder(/var/cache/apt/archives). I need to ...
5
votes
2answers
1k views

Ubuntu tweak and Mozilla (firefox and thunderbird) cache

I usually use Ubuntu tweak to do cleanup jobs on my PC. This includes apt and program cached data and old kernels. This goes alright for most programs except Mozilla based application - Firefox and ...
5
votes
2answers
1k views

Safe to remove…?

I'm trying to customize a LiveCD, but I can't manage to fit it on a normal CD. So I investigated, and came across a few files of which I don't know if it's safe to remove them. Maybe you can help me ...
4
votes
2answers
629 views

Is it advisable to delete ~/.cache files?

~/.cache/* Is it good to delete all the files in .cache folder?
4
votes
1answer
9k views

Can I cache an mdadm raid with an ssd?

I have a 1TB array set up in raid 1 using mdadm on Ubuntu 8, to store mission-critical files. I'd like to speed up read/write, especially for large files by caching to an SSD. Is this possible? Does ...
4
votes
3answers
19k views

Where does my browser store temporary data?

How can one look at content of temporary cache of his computer ? After something not actually downloaded (just pressing the button to open data not download) to any directory, this data temporarily ...
4
votes
3answers
7k views

No window manager after Ubuntu update (e.g. 13.10 to 14.04)

Machine is a single boot Linux. After upgrading from 13.10 to 14.04 today, my son's account starts without a window manager. He has his desktop icons and can click them but no menu and no launcher. I ...
4
votes
1answer
252 views

When running locally, does Juju use the host machine's APT cache?

When juju fetches packages for a unit, does it make use of the host system's APT cache? I'm asking this because in my case, bandwidth is limited and I am doing some charm development. It is not ...
4
votes
1answer
124 views

Is it possible to recover unflushed data from the disk/page cache?

In Ubuntu, I move some file to a USB stick, using mv dir/file /media/7EXXX/swap/. When finishing this, I forget to "safely remove" before physically removing usb stick. Now, the file is not shown in ...
4
votes
2answers
905 views

Possible to use ureadahead to cache frequently used programs?

EDIT I kinda answered my question with the help of this. The only question remaining is how to make the changes permanently stay in the pack-file and not be lost on reprofile. I'll leave the question ...
4
votes
1answer
121 views

How do I partition my SSD to benefit of the speed?

I've watched a few videos on Youtube and read a little bit on the internet about partitioning. But it is still unclear to me how to partition my 4 drives. Besides a Raspberry Pi and VM I have no Linux ...
4
votes
0answers
46 views

What is the optimal configuration for a laptop with a 24GB SSD cache? [duplicate]

I have a Sony Vaio ultrabook that contains a 24GB ssd drive and a 750GB hard disk. What is the optimal configuration for installing ubuntu on this to get the most out of the hardware? Would I be ...
3
votes
3answers
4k views

Why does my system use so much cache?

Previously, on my desktop computer running Ubuntu 14.04, I had 4GB RAM, which I thought should be plenty. However, after being on for a while, my computer would seem to get slow. I have a system ...
3
votes
3answers
721 views

Creating tar fills system cache

My situation is pretty simple: I backup-ed some of my documents and put them on a NAS and since I rather transfer one big file instead of million small ones, I created a tar tar cf backup/2013-07-12-...
3
votes
1answer
41 views

View size of CPU cache through the command-line?

How do I view the size of my CPU cache using the command-line? I want to view information on L1, L2 and L3 cache. Also, would it be possible to ouput only information on cache, so that all other ...
3
votes
4answers
4k views

What Updated Web Cache Servers are available (Caching HTTP Proxy)

I am going to install Ubuntu 11.10 Server (And soon 12.04 Server) and wanted to know what Web Cache servers (Caching HTTP proxy) come with Ubuntu 11.10/12.04 to improve performance and reduce ...