I'm looking for a program that can measure disk latency. I would prefer one that could do it on a raw device. Also reporting average and max latency would be a plus.
Anyone know a program that can do this?
Program code as how to measure interrupt latency..
View 2 Replies View RelatedI'm just wondering what the limits for time are. I have a program that always takes exactly 20 ms, so I assume this is the lowest it can measure, but I want to see if there's some sort of documentation of this.
View 3 Replies View RelatedI have to shred a disk from a custom program. Now I open the disk (/dev/sdaX) from a C program and write /dev/urandom to it. But, most of the time the disk is being used by other programs. At least a 5-10 programs will have files opened on that disk. I cannot kill all the programs as some of them are critical. (Now, don't ask me why I am trying to overwrite a disk which is live and being used by some critical programs. Some moron designed it that way and gave me to implement). Sooner or later, write to /dev/sdaX will fail.
Is there any way (may be some flags that I can pass to open while opening a disk for writing) that I can use so that my overwrite continues even if other program is using the disk? (I am not bothered about what will the other program read and process from the disk when this happens)
How do I find out the memory bandwidth/latency to RAM of the machine?
View 3 Replies View RelatedI'm getting close to ordering the components for a new machine based on the AMD Deneb quad core and had one last question.I'd like to try a little careful overclocking, not only for the performance increase but also to learn how. Nothing extreme, no gaming, just whatever I can get with good stability with the stock heatsink and fan.I was going to get 8GB on 2x4GB strips but they are all CAS latency 9. The MB has 4 slots for a total of 16GB capacity. Would I be better off going with 4x2GB strips and try to get a lower latency strip like maybe 7?
View 5 Replies View RelatedI am having a problem finding a piece of software. I've searched a lot and still have not come up with an answer. My situation is as follows: I have an image file the I wish to restore to my USB flash drive but so far I've had no luck doing this. I was wondering if there was a program/command that could help me restore the disk image.
View 4 Replies View RelatedAs I am trying to understand if there are any advantages using a kernel optimized to have low latency for the desktop, it would very helpful if anyone using one could give me his opinion. I read about the liquorix kernel and found a controversy and used google to find more information.
View 2 Replies View RelatedI tend to use commands like 'aptitude search $something' or 'dpkg -S /usr/bin/command' (some command/variable in both) or 'apt-file search $something' and all/or many of its brethen. I do run updatedb every now and then but that command is for the overall health of the system similar to tracker perhaps (but not running continously like tracker and the daemon).
What I'm looking for is, if there is a way to get the package list (installed and otherwise) updated aggressively so that whenever I use any combination of aptitude or dpkg I get better response from the system. From what little I understand, aptitude or dpkg or somewhere there would be some sort of index/database where the current state of package availability and system state would be recorded. If there is a way that this could be improved upon would be nice to know. If there is some experimental package or road which the debian folks are looking for in the future so this latency can come down.
is there a realtime or low-latency kernel in a repository somewhere for OpenSUSE 11.4? I know I can just compile a rt kernel, but that's a bit tedious and I'd like to avoid it if possible.
View 9 Replies View Relatedwe are setuping high-performance web farm with 4 ubuntu servers (all 10.14 LTS 64bit, i5Core CPU, 16GB Ram). One server is "database" server with mysql installed, three servers are "webservers" with tomcat installed. All three webservers have public IP and are connected directly to internet by eth0 (onboard network card) and are connected to switch that is connected to database server by eth1 (pci network card). All servers has stardard instalation with no special modules/programes installed.
Web servers are already under load, but only on about 10 requests/minute. After several hours in production, strange thing happened - one of the web servers (each time another one, so it is happening to all of them but not at once) starts to have pings to database (that is connected directly on LAN) = 100ms (other two servers still has like 0,02ms). Pings stay high until we do /etc/init.d/networking restart, after that it is fixed and pins are again low again. Another strange think is, that when we let ping running for some time, it is slowly dropping from 100ms to 1 ms and then again jumps to 100ms (exactly to 100ms always) and again starts dropping - so it is cycling over and over again (one cycle takes about 2 minutes).
We were trying reconfigure network, play with switch (the same situation was happening even without switch when there was only one webserver and one database server directly connected), disable IPv6 but nothing helped. The only thing that we discovered is that it has to be caused by network configuration.Do you have any idea what can cause it? We went through systems logs but found nothing suspicious (at least according to our understanding).
It's an eMachines T2899 desktop, FIC AU31 motherboard, nForce2 chipset, AC97 sound (integrated), running Xubuntu 10.04 (wubi install), 2.6.32-22.I've got terrible sound latency (about one second between actions and sound) in some programs.Flash in both firefox and chrome (including ..... videos) and ZSNES (SNES emulator) are two offenders, as is Audacity.Videos played in the default "movie player" and VLC play with no delay, though.I've been told it could be an issue with the ALSA buffer size, or pulseaudio introducing latency... but I've no clue how to go about fixing it.Upon using the SNES9X emulator (which allows for choice of sound system)... Portaudio causes laggy emulation and bad sound latency. Open Sound System plays fine. SDL causes laggy emulation and bad sound latency. ALSA plays fine. Pulse Audio plays fine."sudo apt-get remove --purge pulseaudio" did nothing, so I reinstalled it just in case.
View 4 Replies View RelatedI have a four-cores machine (core1,core2, core3, core4 ). I want to test the communication or latency between two cores (for example, core1 and core2; core3 and core4). Does anyone know how to write a code to test it under linux operating system?
View 1 Replies View Relatedi need to get the hard disk serial number of my machine using a C++ program.
View 11 Replies View RelatedI am trying to load vmware server. When running vmware-install.pl it asks where to load the bin files. Default is /usr/bin. Cool with me, so I accept then get the error:
"There is insufficient disk space available in /usr/bin. Please make at least an additional 5924k available or choose another directory."
Ok, so in my searches, most cases people actually do have a full disk. I have 30gb free. Another post somewhere stated it could be the file system used, so I tried different file systems. Now I am back on etx3. What's odd is when I blow away the OS and reload and try to install VMware again, I get a different number to be "freed" in the error. Choosing another directory only yeilds a different disk space request.
K3b provides a comfortable user interface to perform most CD/DVD burning tasks. While the experienced user can take influence in all steps of the burning process the beginner may find comfort in the automatic settings and the reasonable K3b defaults which allow a quick start. If you want to install K3b goto ubuntu software center and type K3b in such box and press install button After installation is over open K3b when you open for first time you will see a box called "Did you know...? read that and press Next button. After reading all close that box and use K3b for CD/DVD burning tasks. You want to Add-ons for K3b select six add-ons and press Apply Changes button that all you can use it now. If you want to install K3b through Terminal window follow the this commands To install K3b
sudo apt-get update sudo apt-get install k3b Preview audio tracks withing the playlist editor is one of the features in K3b, you need to install and start arts sound server for this sudo apt-get install arts artsd & you may need to install mp3 plugin for built-in decoding software. sudo apt-get install libk3b2-mp3 Enjoy now.
My large ext4 / filesystem seems to cause huge latency problems when writing a large file. For example, if I use split to break up a 40GB file into DVD-sized chunks, my browser becomes unresponsive, and it can take several seconds for Gnome terminal to respond to a mouse click.
I installed LatencyTOP, and it shows jbd2_log_wait_commit as the big offender, with Chrome waiting on that function for over 31000ms (or 31 seconds). I tried remounting / with barrier=0, but that didn't help. My hard drive is a WD20EARS-00MVWB0 2TB SATA disk. I recently switched my BIOS from IDE emulation to AHCI mode, but that didn't help. I tried running split with ionice, and that does help, but the system still isn't responsive as it should be, and I'd hate to have to remember to ionice every large write. Here is some relevant stuff from dmesg:
Code:
[ 1.294068] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[ 1.294096] ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[ 1.294119] ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
[code]....
I'm running kernel version 2.6.38.8-35.fc15.x86_64.
I have a Macbook running Ubuntu Karmic and I have been asked to DJ (amateur to the MAX) a friend's wedding next weekend. I don't have the coin to spend on a Mixer so I can run my mic and laptop through my amp so I figure I'd just run the Mic into the mic input on my Macbook and let the laptop do the mixing for me.Well, I added the loopback module to Pulse and inserted a command to have it auto start:
Code:
pactl load-module module-loopback
Code:
[code]....
I'm looking for an open source/free network emulator tool that I could use on Mac OS X, to simulate a slow network connection, limited bandwidth and other network characteristics such as dropped packets etc for both UDP/TCP connections (or even on the physical layer).
I'm looking for the simplest solution that would allow me to run TCP/UDP servers and have a few clients connect to them on localhost emulating various network connections. I'm mainly wondering if I can use something like Linux's netem on Mac OS X (or even better cross-platform Windows/Linux/Mac). Perhaps I can run VirtualBox and a Linux kernel running netem, has anyone had luck with that?[URL]...
I'm hoping to find an existing Linux tool for measuring latency:
I'm trying to diagnose how much latency my OS and NIC card are adding to TCP latency in Linux. I looked at the following tools but all (at least at the surface level) measured bandwidth (Mbps/sec) rather than latency (nanoseconds for transmition of 1 packet of size x).
If I were to write a custom test, it would likely do the following:
Client:
Create a fake message of the specified length with some padding for an incrementing identifier. Open a TCP connection (with the right parameters like TCP_NODELAY, etc) Loop and send messages containing an incrementing identifier. Store the current system time (in nanos) associated with the identifier. Listen for responses, record the current time and record the latency of that identifier asynchronously Server Listen for a connection Echo back any message received
Assuming both boxes had the same setup (configs, cards, OS, CPU, etc), are relatively close to eachother in the network, and one knows roughly the network's latency contribution, one could get a rough estimate of the OS + NIC contribution and begin testing various configurations.
One could also get a more accurate picture of the latency by using a network sniffer and snooping on the lines between the two hosts, calculating the latency between the two sides for an ID, and then subtracting that from the internally measured latency.
I just installed Maverick Studio on a new hard drive, and am using an NVIDIA GeForce 7300 LE GPU. If I boot into the 2.6.35-22-generic kernel, everything runs fine, but if I try to boot into either the 2.6.35-20-Low Latency, or 2.6.33-29-Realtime kernels (installed from Synaptic), the computer boots straight to a command prompt instead of the desktop. Does anybody know what causes this? I need to be able to use one of these kernels for doing music production.
View 1 Replies View RelatedI'm experiencing massive latency/unreachable problems on my Linux machine. It's true for all network connections, here's an example of me trying to ping my router:
PING 192.168.0.1 (192.168.0.1) 56(84) bytes of data.
64 bytes from 192.168.0.1: icmp_req=1 ttl=64 time=15115 ms
64 bytes from 192.168.0.1: icmp_req=2 ttl=64 time=14107 ms
64 bytes from 192.168.0.1: icmp_req=3 ttl=64 time=13107 ms
64 bytes from 192.168.0.1: icmp_req=4 ttl=64 time=12107 ms
64 bytes from 192.168.0.1: icmp_req=5 ttl=64 time=11108 ms
[Code]...
I've tried now with both the maverick default kernel and 2.6.37-rc5 kernel (both 64 bit), same result. If I take the card up and down (ifup, ifdown) performance is restored for a little while, then it's back. I've tried changing cable, network card and router port but no luck.
i have installed ns 2.33 and added the patch mobiwan for supprting mobile ipv6. i ran some tcl scripts , and below is the trace file generated. calculate the handoff latency, and if someone has awk or perl script to do so, tcl file [URL] out.tr [URL]
View 1 Replies View RelatedI have a dedicated host on my lan to monitor other hosts/services using Nagios. I'm in the process of migrating to Zabbix on that host to perform the same purpose. Both Nagios and Zabbix monitor icmp ping latency (Nagios uses ping, Zabbix uses fping) and over time the latency to other hosts grows until threshold alarms are triggered. In one week, the average latency grows from sub-millisecond to over 100 milliseconds, and continues to grow until the Nagios host is rebooted. I have verified the latency numbers using ping/fping from the command line on the Nagios host.
The problem is that pings from the monitored hosts to the Nagios host show normal latency at the time the Nagios host is showing high latency from itself to the monitored hosts. The Nagios host and monitored hosts are all connected to the same Dell 24 port gigabit switch. I already posted this question on the Zabbix forums with a graph of the latency but there were no answers. [URL] why the icmp ping latency is growing over time and how I can fix it short of rebooting the host on a schedule.
[Code]...
Could you suggest feature-rich disk-based personal backup program for Linux (and I've seen a few)?
I want to do nightly backups of the whole system and be able to rollback to any of last 7 days. And, it must be incremental backups. What tool should I use? The tutorials I've read about rsync tell only how to store latest incremental backup and I need last 7.
adding some program packages doesn't seem to be working out of add/remove, asking me to insert Ubuntu 8.10 _Intrepid Ibex_ - Release i386 (20081030) which i believed to be the 8.1 desktop release i received with the laptop. doesn't recognize it. is this the wrong cd?
View 3 Replies View RelatedI have now almost completed my aim of using Debian and PClinuxOS on different installed hard disks. For PCLOS I use an On-Disk set of disks which I have installed on a separate hard disk which serves as a repository from Synaptic, which makes program install/remove very quick. Is it possible to do the same thing with the 5 DVD's for Debian lenny on another hard disk?
View 2 Replies View RelatedI have a lot of RAR files and ISO. Is there a program like Winrar which could open them in Linux? Cause now it only opens zip files . Also I would like to know what the best package manager is (I mean the easiest -used to use the Software Manager in Mint 9 Xfce).At last I would like to know if there is a good program to make disk images to reset the system.
View 9 Replies View RelatedI am having trouble trying to figure out how to switch over to Ubuntu. I have downloaded the OS to my computer but can't figure out how to put it on my USB flashdrive as directed. It shows how use your USB flashdrive using Windows, Mac and Ubuntu but when I read the instructions for Ubuntu, opensuse does not have the program Startup Disk Creator.
View 9 Replies View RelatedI just put 10.10 on my D830 and I love it except for a delay when I'm using the internet. When I click on a link while surfing the web it takes about 13 seconds before it responds. After that it works just fine.
My Windows 7 PC and my Macbook Pro don't do that so I'm guessing it has something to do with Ubuntu.