2
votes
3answers
488 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 ...
2
votes
1answer
326 views

zram vs zswap vs zcache Ultimate guide: when to use which one

What the hell are they? how are they different (I've written my understanding in an answer below) In the Zswap system, when a page is evicted from the zswap to the actual swap is it stored in a ...
1
vote
3answers
136 views

Ubuntu Frozen every time when Memory usage over 80%

Ubuntu Frozen every time when Memory usage over 80%, It seems that the system hangs due to a load of disk IO - the screen is frozen and the only thing I can see is the indicator LED of disk keeping ...
1
vote
1answer
67 views

Help with ram usage

I have a dual boot laptop with 512 MB RAM running Windows XP/Xubuntu. I try to load student.portal.chalmers.se (a huge bloat site) in Firefox. On XP, I can load the site without any swapping, but ...
2
votes
1answer
162 views

Why does rsync slow down my whole computer?

My powerful Linux desktop (12 core, 32GB RAM, SSD, fast processor, ubuntu 13.10) slows down to a crawl when I rsync from my internal drive to an attached USB3 NTFS drive. Typing any command, like "df" ...
2
votes
2answers
122 views

Performance tuning - multiple swap partitions? (command-line)

SUMMARY Does Ubuntu take advantage of multiple swap partitions on separate physical media, from a load sharing point of view? i.e. if one drive with a swap partition is burdened with i/o, will it ...
1
vote
2answers
3k views

How can I enable zswap?

Ubuntu 13.10's release notes mention that it includes Linux 3.11, which supports something called zswap: Zswap is a lightweight, write-behind compressed cache for swap pages. It takes pages that ...
1
vote
2answers
729 views

defragmenting and increasing performance of old lubuntu system with swap partition

I am using the latest Lubuntu on an Intel Celeron 1.7Ghz and 512MB RAM. Lately system performance has deteriorated significantly. The hard disk is an 80GB IDE drive and we suspect it to be the ...
20
votes
5answers
15k views

Why most people recommend to reduce swappiness to 10-20?

I have seen in several site which recommend to reduce swappiness to 10-20 for better performance. http://community.linuxmint.com/tutorial/view/998 ...
2
votes
2answers
4k views

Ubuntu swappiness

I have a laptop with 4 GB RAM and i3 processor. It runs very fast when I use windows, but it keeps slowing down on my Ubuntu when I use it continuously. I noticed that 500mb+ swap is getting used even ...
0
votes
2answers
1k views

Swappiness setting ignored in systcl.conf

My Ubuntu 12.04 x64 on Dell XPS 15 with 8GB of RAM has been really sluggish. After some searching I came across post about swappiness. I noticed that swappiness on my system was reported as 0 which ...
1
vote
3answers
578 views

Disk I/O makes desktop unusable. System consumes too much memory

I have a long-term problem with my Acer TravelMate 3002WTMi (Pentium-M 1.73Ghz, 512 MB RAM) and Xubuntu 11.10. Whenever load increases machine tends to slow down to the point that it's totally ...
5
votes
3answers
2k views

Ubuntu sometimes starts swapping like crazy for no reason

Every once in a while, my Ubuntu starts using the hard disk like crazy, and for 3 minutes I can't move the mouse nor access any console, even CTRL-ALT-BACKSPACE and CTRL-ALT-F1 do nothing. It is ...
2
votes
4answers
1k views

Would I benefit from reducing, or increasing swappiness?

I've read a few articles now about changing the swappiness level on Ubuntu to possibly increase performance. But I'm very unfamiliar with how swappiness works, would I benefit from increasing, or ...
34
votes
9answers
40k views

How to empty swap if there is free RAM?

When I open a RAM-intensive app (VirtualBox set at 2GB of RAM), some swap space is generally used, depending on what else I have open at the time. However, when I quit that last application, the 2GB ...