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3
votes
1answer
659 views

How does irqbalance determine which package to use?

irqbalance --debug shows the following: Package 0: Core 0, 2, 4, 6, 8, 10, 12, 14 Package 1: Core 1, 3, 5, 7, 9, 11, 13 When I run network applications, it seems like IRQs are being handled by ...
2
votes
2answers
399 views

why is filesystem intensive script not faster on ram disk

I have a script which creates a lot of files and directories. The script does black box tests for a program which works with a lot of files and directories. The test count grew and the tests were ...
2
votes
1answer
1k views

Does encrypting my whole Lubuntu slow running programs down?

During the installation of Lubuntu I chose to encrypt my whole HDD (not just the /home folder). Now it feels like my system has slowed down a lot. Especially the startup time of programs increased. ...
0
votes
1answer
139 views

udevadm slow boot

After I upgraded from Slackware 13.70 to 14.0, when the machine is booting, it takes it 15 seconds to execute this line: /sbin/udevadm trigger --action=add I understand, that it tries to detect ...
0
votes
1answer
196 views

Open screen in terminal after user login [duplicate]

When a user logins to my Debian server using e.g. Putty, I need to perform the following: It will automatically execute command screen -r MyWindow, and the user won't be able to leave the screen ...
6
votes
1answer
544 views

Determining LVM Extent numbers for given file

I'm currently engaged in a non-work related homework exercise. I have an ext4 filesystem sitting on a logical volume. I'm testing different performance tuning strategies and this idea occurred to me. ...
1
vote
1answer
130 views

Establishing I/O Patterns for an Application

Are there any system tools that allow you to profile an application's usage of storage? Basically, I'm looking for information on determining whether there are more large sequential reads, tiny ...
0
votes
1answer
339 views

USB Drive Software Disk Mirroring - Is this the right approach?

I have a 1TB NTFS USB Data Drive (no boot, etc...) that I would like to keep a mirror of as a backup in case of hardware failure. It is always connected to my raspberry pi running the raspbian ...
2
votes
1answer
513 views

Best way to encrypt my system on an ssd

I consider to buy an ssd for my laptop (something like Samsung 830 or 840) to make the system more responsive. I want my system (at least my home partition) to be encrypted. However I know about ...
4
votes
4answers
289 views

Grep of many keywords over many files: speeding it up

I am currently facing a "performance problem" while using grep. I am trying to locate the occurrences of many (10,000+) keywords in many (think Linux kernel repository size) files. The objective is to ...
0
votes
1answer
494 views

NFS server optimization for maximum performance

I'm looking for maximum of performance for a NFS mount. I'm on local network, it could be completly unsecure, the performance is the most important in my case. What I already found : In /etc/export ...
9
votes
7answers
3k views

Processor usage increases with 4GB RAM installed

I have an Intel Atom D2700 (Synology NAS DS412+) with 4GB RAM running kernel 3.2.30 x86_64. This unit has a single DIMM slot. One thing I, and other's have found, is that when adding a 4GB DIMM ...
2
votes
1answer
850 views

Huge page and performance improvemnt

How can using huge page improve performance? I have read that huge pages improve performance by reducing TLB lookups and reducing the size of the page table. Can someone tell me how this helps with ...
4
votes
2answers
718 views

Is there any performance penalty to having multiple segments for one volume in LVM?

We have a big drive that we've split up using LVM. We allocated one segment to the root filesystem and several other segments to other filesystems. Then we wanted to add more space to the root ...
1
vote
1answer
410 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
457 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
743 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
118 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
117 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
246 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
589 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
351 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
579 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
875 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
627 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 a ...
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
713 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
200 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
454 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
221 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
988 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
323 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
203 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
139 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
152 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
989 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
268 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
880 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
945 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
678 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
171 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
2k 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
248 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 ...