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27
votes
4answers
11k views

Is there a way to determine the optimal value for the bs parameter to dd?

On occasion I've seen comments online along the lines of "make sure you set 'bs=' because the default value will take too long," and my own extremely-unscientific experiences of, "well that seemed to ...
5
votes
3answers
1k views

Fast way to build a test file with every second listed in YYYY-mm-dd HH:MM:SS format

I want to create a large test file with lines containg dates listed by the second, but my method is taking inordinately long... (or at least, that's how it feels :) ... 43 minutes to create only ...
-1
votes
3answers
272 views

Improving OpenOffice speed [closed]

I'm looking for some tips and tricks on how to improve the performance of OpenOffice on my desktop. Any ideas, tutorials or articles on this? Thanks in advance!
1
vote
1answer
519 views

what could cause large pagefault latencies in linux?

I'm running a Linux netbook with an SSD. Since the SSD is slow (and I don't want to wear it out) I've been running without swap. So far this has been great, but I recently put a new kernel on (2.6.37) ...
9
votes
1answer
2k views

How to make dpkg faster?

Package (un)installation on a Debian system is horribly slow, partly because it works with a whole bunch of (small) files. Short of getting faster storage, how do I speed it up? I'm thinking maybe ...
4
votes
1answer
545 views

“Split I/O”s on a Linux VM, disk alignment

I'm trying to figure out if there's some way I can tell if a system is being adversely affected by disk misalignment -- i.e. when I do a disk I/O operation, it actually needs to request extra blocks ...
21
votes
6answers
6k views

Force directory to always be in cache

I've been testing out different methods to improve the time it takes to compile my entire c++ project. Currently it takes ~5 minutes. I experimented with distcc, ccache, and others. Recently, I ...
11
votes
4answers
7k views

Use of O_DIRECT on Linux

If this question is too programmer oriented, let me know. I wonder if there are people familiar with the O_DIRECT flag for the open() system call on Linux 2.6? Linus disparages its use, however high ...
2
votes
1answer
418 views

xorg performance in openoffice

I've just been monitoring my cpu usage in openoffice calc when cells have been copied vs when they haven't and seen a dramatic increase in cpu usage for the Xorg process. The additional rendering ...
14
votes
2answers
5k views

Why does high disk I/O reduce system responsiveness/performance?

I never quite understood why high disk I/O slowed the system so much. It's strange to me because I would expect the slow-down to affect only those processes dependent on the hard/optical drive data, ...
9
votes
1answer
1k views

What's the progress regarding improving system performance/responsiveness during high disk I/O?

Whenever there is high disk I/O, the system tends to be much slower and less responsive than usual. What's the progress on Linux kernel regarding this? Is this problem actively being worked on?
10
votes
1answer
5k views

How can I configure cgroups to fairly share resources between users?

There used to be a kernel config option called sched_user or similar under cgroups. This allowed (to my knowledge) all users to fairly share system resources. In 2.6.35 it is not available. Is there a ...
6
votes
3answers
717 views

zsync vs. jigdo

What's the difference between zsync and jigdo? Their core functionality seems the same, so I'm curious on things like performance, file size, and ease-of-use. Would also be interesting to know why one ...
7
votes
6answers
3k views

Sync writes very slow. Ubuntu 10.10, 32 bits, ext4

I am running ActiveMQ on my Macbook Pro that runs Ubuntu 10.10, 32 bits with an ext4 partition. Linux iker-laptop 2.6.35-23-generic-pae #40-Ubuntu SMP Wed Nov 17 22:32:51 UTC 2010 i686 GNU/Linux If ...
6
votes
2answers
802 views

I/O-overhead of dm-encrypted device?

What would be the Read-/Write-overhead when using dm-crypt (LUKS) as full disk-encryption (including root partition) on a Linux-Desktop (Ubuntu)? I plan to stack it like so: LUKS > LVM > ext4 The CPU ...
15
votes
5answers
7k views

Is there a parallel file archiver (like tar)?

Is there something out there for parallel archiving of files? Tar is great, but I don't use tape archives, and it's more important to me that the archiving happens quickly (with compression like ...
79
votes
7answers
22k views

Why use swap when there is more than enough free space in RAM?

Using swap space instead of RAM can drastically slow down a PC. So why, when I have more than enough RAM available, does my Linux system (Arch) use the swap? Checkout my conky output below: Also, ...
2
votes
4answers
6k views

What is “System Memory ” displayed in nmon in AIX?

I have a host with AIX 6.1 (6100-04-02-1007) upgraded from AIX 5.1 with Veritas Storage Foundation 5.1. Since the upgrade from AIX 5.3 to 6.1, Run vx services means a lots of memory consumed that I ...
6
votes
4answers
209 views

Quantify unix responsiveness

I am one of the n users of a shared unix machine. For reasons unknown, the machine is not "responsive" enough. For example, it is slow on interactive commands, it takes few noticeable moments for any ...
6
votes
2answers
6k views

Diffing two big text files

I have two big files (6GB each). They are unsorted, with linefeeds (\n) as separators. How can I diff them? It should take under 24h.
3
votes
2answers
759 views

Does the Linux PreemptRT patch benefit desktop users?

Does the PREEMPT_RT patch (real-time kernel) have any benefit for regular desktop users?
16
votes
2answers
3k views

Measure pipe throughput in the shell

There is a shell command that allows to measure how fast the data goes through it, so you can measure the speed of output of commands in a pipe. So instead of: $ somecommand | anothercommand you ...
21
votes
11answers
7k views

the lightest way to have a GUI in Linux?

I have been using Gnome and KDE for a while, and I am now running Compiz standalone... Regarding system resource, I think the most heavy ones are feature-rich desktop environments (Gnome, KDE), then ...
10
votes
2answers
1k views

Heavy write activity on SSD nukes system performance

I've noticed that when I do heavy write applications, the whole system slows down. To test this further I ran this to do a (relatively) low-CPU, high disk activity: john -incremental > file_on_SSD ...
6
votes
5answers
7k views

Why is this network connection so slow?

I am having some problems with network performance speed on a Linux server running Ubuntu 9.10. Transfer speeds on all types of traffic are around 1.5MB/s on a 1000mbit/s wired ethernet connection. ...
5
votes
5answers
2k views

How do you free up resources in Ubuntu?

What steps do you take to make a vanilla Ubuntu system run faster and use less memory? I'm using Ubuntu as the OS for my general purpose PC, but it's on slightly older hardware and I want to get as ...
11
votes
1answer
531 views

How do I go about tracking down IO usage in Linux and other *nix OS'?

Occasionally, something on my system starts hammering the disk. I would like to log data that would let me know about I/O usage per process, then I could go back to it later and see what keeps doing ...
7
votes
2answers
913 views

Has anyone got any performance numbers comparing IIS and .NET to Cherokee and Mono?

I am setting up a development server and want to set it up to serve ASP.NET pages using Mono. I am planning on using Cherokee and Mono (http://www.cherokee-project.com/doc/cookbook_mono.html) and ...
25
votes
12answers
3k views

How can I tweak my Linux desktop to be more responsive?

I have the experience that Linux works fine until the physical memory is exhausted. As soon as swap space is used the performance is severely degraded and the GUI becomes unresponsive. This problem ...