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1
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1answer
385 views

Speeding a find rm command with test through parallelization

I want to recursively delete all files in directories and subdirectories with number of lines less than 10, and am currently using the following command find . -type f -name "*.txt" | while read; do ...
1
vote
1answer
440 views

vmstat on virtual machine and large values

Hi I'm using vmstat to track machine performance during some tests (jmeter). This is virtual machine running on a big machine where lots of other virtual machines are installed (about 20 virtual ...
3
votes
1answer
723 views

Measure hard-disk read(), write() speed without caching in QNX 6.5

I am working on QNX 6.5 Operating system. QNX 6.5 supports POSIX APIs. I am trying to build an application which is used to evaluate performance of hard-disks. My application will read/write/read ...
1
vote
1answer
117 views

How to configure Linux to run benchmarks as stable as possible?

I have several long running benchmarks (SPEC CPU 2006 benchmarks) to run on a Linux server. The server is running Gentoo Linux with a Linux Kernel 3.6.11. I saw some big differences between ...
1
vote
2answers
116 views

When all hardware resources are free what would cause linux to run slowly

Sometimes, after a few hours, my system works slowly. I have checked status of these resources: Hard disk using iotop Ram usage using free CPU usage using top None of them are busy. top also shows ...
2
votes
1answer
240 views

Alix Board write performance

I have an alix board on which I have installed debian4alix (sqeeze). After using it for a while I noticed that the write performance of the board was pretty low. I ran the following test: dd ...
1
vote
2answers
571 views

btrfs performance

I decided to mess around with btrfs and found some weird performance anomalies. The tests I've done are with with two external hard drives one formatted with ext4 the other btrfs. ext4 performance ...
2
votes
0answers
340 views

Local disc copy at 10MB/s! What could be the problem?

I am running a Debian 6.0.6 (before you ask). I have a regular desktop computer, nothing fancy... but when I copy a file using nautilus I am getting 10MB/s copy speed and the system is completely ...
2
votes
1answer
550 views

Why is connecting to Oracle Express 11 is very slow on Fedora 17?

I installed oracle-xe-11.2.0-1.0.x86_64.rpm on Fedora 17-64-bit. I was wondering why it is very slow, for example when I want to connect to it using Oracle SQL Developer or JDBC in my web application. ...
5
votes
2answers
835 views

Linux (3.4) SSD swap partition usage causes extreme latency - how to eliminate?

I'm running on 4G RAM with an extra 6G swap partition, SSD is a pretty decent SAMSUNG MZMPA128HMFU model. System responds very well to workloads when things stay in RAM, but as soon as things reach ...
9
votes
2answers
2k views

echo vs <<<, or Useless Use of echo in Bash Award?

By now the Useless Use of cat Award is very well known, and there's also a mention of a Useless Use of echo (not relevant for this question). I'm wondering if there should be a "Useless Use of echo in ...
3
votes
2answers
2k views

Optimal SSD configuration

I am thinking about buying an SSD for my Debian system. However, because I don't know what is the optimal arrangement (i.e. what goes on the SSD), I am not sure what is the optimal size. Obviously I ...
0
votes
1answer
588 views

Rygel slowing down my Debian system

Recently I noticed that a process called rygel is taking a lot of IO resources every time I am starting something on my home system. What is this process doing and how can I disable it?
3
votes
3answers
2k views

Performance virtualbox diskfiles vs rawdisk

Pros and cons with this two ways to make disk for virtual machines on virtualbox $ vboxmanage createhd --format VDI --size ${SIZE} --filename /path/to/disk.vdi and # vboxmanage createrawvmdk ...
0
votes
2answers
2k views

Console CPU utilisation chart

I need to monitor CPU and network utilisation from a terminal. For network traffic, I have found the perfect tool: slurm It gives me a moving chart. It gives me an nCurses-like UI I can use from ...
3
votes
1answer
1k views

Linux disk I/O performance issue — what config options to look at?

We discovered an I/O related performance problem when using the default SLES11 SP2 kernel. Our same application on the same hardware had no issue with (the admittedly ancient SLES9 SP3). We had a ...
2
votes
0answers
694 views

Send print job to printer immediately without queueing, aka increase print performance

I have a ruby/rails web application, one action of which sends PDF files that have been generated by the app to a Xerox 4127 printer on the network. This is accomplished via shelling out and running ...
1
vote
1answer
189 views

Does symlinking from Drive A to Drive B affect I/O on Drive A?

I was wondering if IO through a symbolic link affects IO on the host drive even if it points to a seperate drive? My setup is, /dev/sdb2 1.8T 443G 1.3T 26% /home1 /dev/sda3 1.8T 1.7T ...
2
votes
1answer
448 views

Why if I don't disable nm-applet and xfce4-volumed my startup slows down?

I'm running Xubuntu 12.04, and after I ran the update, my login started slowing down big time. I've dabbled a little bit with the programs in Settings -> Settings Manager -> Session and Startup, and ...
0
votes
2answers
213 views

Is it against linux ethos to provide a progress indicator for running commands? [duplicate]

Possible Duplicate: Why doesn't cp have a progress bar like wget? Lately I have been dealing with rather large files in Linux. I often use commands like sed, cut, sort, uniq, awk, and ...
4
votes
2answers
961 views

Does the filesystem influence flash drive speed?

I'm currently filling up an empty 16GB flash drive which gives me a lot of time for imponderables. It's formatted as fat32 or whatever it came with (and I'll probably leave it that way for ease of ...
2
votes
1answer
313 views

Book or online article on analysis and tuning Linux system performance [closed]

I am looking for a good book or online article on analysis and tuning Linux system performance. So far I've found openSUSE 12.2 System Analysis and Tuning Guide which looks promising. Any other ...
4
votes
1answer
200 views

Linux mutex spins [closed]

On Solaris I can use mpstat to see the smtx (i.e., spins on mutex or in other words locks not acquired on the first try) value. This value increasing indicates that swap is being hit too frequently ...
5
votes
1answer
2k views

Fast elimination of duplicate lines across multiple files

I have a huge amount of data in which each (data-)line should be unique. There are a lot of files in one folder in which this is already true. It is about 15GB splitted into roughly 170 files with ...
2
votes
1answer
134 views

Read only new parts of a file?

I have a large CSV file, that grows by some entries every day (created by an external software which writes always to this one file, no splitting possible). For performance reasons and further ...
9
votes
1answer
3k views

Defragmentation of LVM2 logical volumes

Question: Is there a tool supporting de-fragmentation of LVM2 logical volumes ? (Making their extents into consistent sequences) Preferably by defining desired order of extents (something like ...
2
votes
1answer
150 views

How to have find only search for files in changed directories?

Currently I'm repeatedly doing a 'find' that's too slow. I'm searching for non-hidden executable files within "$root", excluding "$root/bin": find "$root" -type f -perm -o+x -not -path "$root/bin/*" ...
7
votes
2answers
924 views

Replace require statements by autoload in .emacs file to improve performance

According to these posts: How can I make emacs start-up faster a-nickels-worth.blogspot.de/effective emacs one can somehow replace require and load statements in the .emacs file to speed up the ...
3
votes
1answer
260 views

Tweak gimp for performance

I just realized that I can start gimp (version 2.8) via gimp -d to reduce startup time on an old system. Are there other tweaks to speed up the startup time of gimp and reduce memory usage?
3
votes
2answers
844 views

What could cause a NAS mount to respond slowly?

I've a directory on a NAS mount (from NetApp), that contains ~6300 image files, total size of this directory is ~ 300 MB. I get two different performances of time ls: First time (or after waiting 5-7 ...
8
votes
2answers
914 views

What keeps one side of an rsync so busy?

I've got a Debian machine on my LAN serving as a backup server for the others. It has four HDDs combined into a software RAID 5 md device, on that an LVM, and on that btrfs. Backups are made using ...
7
votes
1answer
2k views

Why is ping so slow?

My setup: Server in the cellar + GBit switch. Long cable to the roof. GBit switch. I have three computers in the roof. One has only 100MBit ethernet, one laptop with GBit and a new computer. Ping ...
6
votes
2answers
648 views

Does the position of partition on disk affect speed?

If I put /var as first partition, then /home and /, will the partition for /var have better performance than if I put other partitions close to head of the disk? Will the disk sector position matter? ...
2
votes
1answer
169 views

How to find what's hogging what resources? [closed]

I've found lots of similar questions, but nothing that's exactly right. I'm trying to figure out what's making one server run slower than another. I'm hoping for something that would say something ...
4
votes
2answers
1k views

Linux running slow with 0 swap left

Our Linux server is responding very slowly. top doesn't show any excessive CPU usage. I noticed that even though there's about 5GB of free memory, the system is using all of swap with no free swap ...
0
votes
0answers
241 views

write file to NFS speed issue

I have a big data file need to write to NFS directory which is mapped under a Windows system. I had 2 different approaches to achieve this. I wrote (using the “save as” command) from the app directly ...
5
votes
4answers
2k views

How to get better desktop performance in linux?

Normally I do not care much about desktop - performance, since my servers do not run any gui. But at home I run some older hardware (Pentium) which gets sometimes very sluggish (mouse-movements in ...
4
votes
2answers
995 views

Is it possible to trigger OOM-killer on forced swapping?

Is it possible to have the system preemptively swap out inactive pages (vm.swappiness), but invoke the oom-killer when the system runs out of RAM (as opposed to running out of memory) and is forced to ...
3
votes
2answers
1k views

NFS Option Reload without Service Restart

What do I need to do to change the RPCNFSDCOUNT setting without a full service restart? I need to reload the NFS configuration without restarting the service. The RPCNFSDCOUNT thread count is too low ...
3
votes
1answer
483 views

How do I tell if a Wine application uses hardware or software rendering?

I'm building an appliance/kiosk-type machine which is going to run a single fullscreen Wine application (Synthesia). I'm using Arch Linux running LXDE on an original 7-inch EeePC (well, souped up to ...
13
votes
1answer
2k views

Is disabling barriers for ext4 safe on a laptop with battery?

The manual page says about the barrier option for ext4: Write barriers enforce proper on-disk ordering of journal commits, making volatile disk write caches safe to use, at some performance ...
2
votes
0answers
507 views

“Remote function call interrupts” (CAL in /proc interrupts). What is it?

I'm running a test program which generates a large number of threads and asynchronous I/O. I'm seeing very high counts of these interrupts in /proc/interrupts, the program cannot scale beyond a ...
6
votes
1answer
6k views

How to configure a filesystem+LVM for effective usage of SSD?

ext4 is one of the filesystems recommended for using on SSDs (with a number of built-in techniques and advices how to tune it for better performance and wear-levelling of SSDs). I want to install a ...
7
votes
1answer
2k views

Throttling web crawlers

My website is being DoS'ed by Google webspiders. Google is welcome to index my site, but sometimes it is querying a tagcloud on my site faster than my webserver can produce the results, making my ...
0
votes
2answers
398 views

Optimize command yum

I would like knowing if there is a way to increase the performance of the command yum to install and search packages. I'm a very happy new user of Fedora 16.
2
votes
0answers
223 views

Connected external HDD slows down system

I need to connect large external hard disks (with many many files) to a system running Ubuntu. I have no idea how the Linux kernel is treating the inodes for the external drives, but attaching huge ...
2
votes
0answers
230 views

Perform test of aes-ni and aes module in linux kernel

Since both aes-ni and aes module are available in linux kernel , how can I give it a performance test , to decide which one's faster ?
2
votes
1answer
267 views

How do I record disk performance on slow hardware and then replay it to faster hardware and benchmark it?

I am currently performing various development tasks that are slow on my current system because of IO performance. Is there a way to record disk operations while performing IO consuming tasks, ...
4
votes
1answer
2k views

What's faster, dd 1.5TB or rsync 500GB?

I need to save data from a failing hard drive. Sounds like ddrescue or myrescue (or maybe clonezilla?) will be my best friends here, but I'm just wondering what will likely be faster: using ...
2
votes
0answers
305 views

Software raid checksumming slow

On my new 24 disk array I get 900 MB/s of raw read or write using dd to all the disks. When I set the disks up as a 24 disk RAID6 I get 400 MB/s write and 600 MB/s read. It seems to be due to ...