At times I see heavy hard-disk activity slowing down system.I have enough RAM and enough of it free.Apparently I am not doing anything that should cause this.'vmstat' shows high numbers for "bi bo" I want to find out which processes are doing "bi bo".How can I zero in on the particular processes?What command?
View 3 Repliesuser@user-laptop:~$ sudo dd if=sd_backup of=/dev/sdd bs=4M conv=noerror,sync
205520896 bytes (206 MB) copied, 28.564 s, 7.2 MB/s
247463936 bytes (247 MB) copied, 57.1285 s, 4.3 MB/s
260046848 bytes (260 MB) copied, 73.2388 s, 3.6 MB/s
289406976 bytes (289 MB) copied, 104.121 s, 2.8 MB/s
[Code]....
How come dd gets slower after copying this 8GB file? What can I do about it?
I've been able to get access to our Netgear NAS, I can browse it, copy files etc. just fine. But I don't have "direct access" in as far as, Open Office won't open any files residing on the NAS, neither can I save directly to the NAS form a program and when I get a "Browse for File" form field on a website (eg attachments in GMail etc.), I can't browse to the NAS either. My XP box does do all of this, either through my mapped network drive or even through browsing the network. How can I make openSuse 11.2 use the NAS with my login credentials as if it was a local disk?
View 4 Replies View RelatedI've used ext2ifs drivers to mount my ext3 partition in winxp, but I don't have write acces, it's mounted in a read-only mode, and i didn't check the rad-only box during the installation of the drivers. [URL] It's a straithfoward proces so I dont understand what I did wrong. I'm using fresh xp install with (more or less) all the updates and ubuntu 10.04 Also the partition is mounted at /home, so I dont know if that makes any difference.
View 1 Replies View RelatedI've used ext2ifs drivers to mount my ext3 partition in winxp, but I don't have write acces, it's mounted in a read-only mode, and i didn't check the rad-only box during the installation of the drivers.I've used help from the official site http://www.fs-driver.org/and this tutorial http://www.dedoimedo.com/computers/l...s-windows.html
It's a straithfoward proces so I dont understand what I did wrong.I'm using fresh xp install with (more or less) all the updates and ubuntu 10.04Also the partition is mounted at /home, so I dont know if that makes any diferance.
My main workstation incorporates a mixture of ext3, ext4, and NTFS partitions scattered across a number of hard drives. Several of the ext4 partitions are encrypted, and I intend to encrypt the rest of the Linux partitions in the near future.I run VMware workstation, with several Windows OS guests, including Win2K, WinXP and Win7. My Win7 VM is installed on a virtual hard disk, and that virtual hard disk is encrypted using VMware facilities.So this leaves me with a bunch of NTFS partitions that are not encrypted. These are physical partitions on a couple of different hard drives. The reason I have them is ancient and historical, and as I have upgraded my system over time I have maintained the architecture due to the extreme difficulty of rearranging Windows systems.I still need to maintain Win2K and WinXP support, and rearranging those virtual machines would represent a hideous nightmare for me; I really want to maintain the same hard drive partition architecture.But I want to encrypt the NTFS partitions, in a fashion that can be handled by any of the Windows operating systems, AND can be accessed for read and write from Linux.Is this possible? If not using Windows facilities (I don't think ntfs-3g handles encryption, and there are known backdoors in the Windows facilities anyway), is there any third party solution that would work? Would True Crypt do the job in a fashion that would permit access from all the various operating systems, as required? I do generally mount the NTFS partitions in whichever Windows VM is appropriate, then share them out via SMB, but there are circumstances (like when a VM is not running) where I will directly hit them from Linux. So, it is possible for me to contemplate a solution that only works from Windows, but this would cost me the ability to repair/modify those filesystems directly from Linux, which under certain circumstances (a malfunction of the VM, for instance) could be a problem.
View 2 Replies View RelatedI am about to write a program to listen and read data from /dev/ttyS0 and write the data to /dev/ttyS1 after processing. Also, the same time I need to listen to /dev/ttyS1 and write to /dev/ttyS0 if any data arrived at /dev/ttyS1.
View 9 Replies View RelatedReading and writing text files in C?
View 9 Replies View RelatedI would like to write a program that can read every ethernet frame arriving on a specific hardware NIC, without a TCP/IP stack otherwise doing anything on that NIC. Likewise I want to be able to write out to that NIC. So every arriving ethernet frame, of all types, would be readable (probably one at a time to preserve frame boundaries). And every write of exactly that same data would send frames out. The data read and written would be the whole ethernet frame. The kernel would do nothing else with this data, but other NICs would still operate as usual.
What I would be doing is that on 2 separate NICs, copying frames from one to the other, as in bridging. But I would also be doing modifications per what my program needs to do (not at liberty to say what that would be). What facility would I need to be looking at to do this? There is no ethernet device file. Would raw sockets be able to do this? The programming language will be C.
I just want to read and write some values (integer) to my driver. I used put/get user but always getting errors.
driver
Quote:
int Wert;
static int device_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsinged long arg)
int ret;
[code]...
Quote:
int WERT
ret=ioctl(fd, SETIT, WERT)
ret=ioctl(fd, GETIT, WERT)
if i say in C++ WERT is 5 the value arg of the driver becomes 5 but not WERT the returnvalue of get and put user is -1 so it failed.
I want to be able to access my email account from the console. I'm reading all day about fetchmail, postfix, sendmail etc. but all the stuff I found is related to building whole mail system. All I want to do is to read my emails and write some. Which is the painless way to do this? I successfully configured Evolution for this purpose but I want to do that from the console.
View 10 Replies View RelatedI am trying to read a file character wise and trying to write the same character to another file. In this process, I unable to read and write white spaces successfully to the new file. The script reads the white spaces but while writing the white space is lost. The section of the code, is given below. Please advice how can i read and retain the white space while writing to a new file.
Code:
if [ -s f_test.txt ] && [ -f f_test.txt ]; then
echo "File Exists !!"
while read -n1 char; do
[code]....
There is the Archive::Zip I think I can use with Perl 5.10 but I don't know how. I don't want to read or write any files, just zip something in memory, with best compression, like
$text = "this is a test";
$zippedtext = &Zip($text);
sub Zip {
[code]...
I guess it's only a few lines.
It it safe to read a shared integer while another thread is writing to it on a multicore system?
View 3 Replies View RelatedHere the description of the issue I am having.I am writing a bash test script which reads lines from a file, builds ISO messages, sends them to a server, reads the response with response code and reports the result of the test to a file or on the screen.The message that I need to send is 94 characters long.Here's the portion of a code that I initially wrote:
~ Open socket.
exec 3<>/dev/tcp/172.26.0.25/9991
#~ Send msg.
[code]...
Samba seems to crash and come back after some seconds if I copy a lot of small files in a short period of time over the network. How do I fix it?
I have Ubuntu 9.10 Server 64bit running on a D945GCLF2 board sharing two 1TB ext4 formatted HDDs to my Windows PCs using samba. I've been having an issue with reading or writing files through samba. It happens during copying operations or checksumming, anything that reads or writes MANY small files in a small amount of time. I am pretty sure the problem has to do with my server because the server has run on two different LANs in different homes and will crash from activity with any of several other PCs. There is no crashing if I access the files through SSH, although when I do that the max transfer speed is less than 1MB/s.
When I induce the crashing, there is absolutely no output to the server terminal.
As an easy access example of something that will crash samba, extracting Cinebench R11.5 to the server will do the job. It always fails.
Whenever I am busy reading or writing large files, or large sum of files, my computer is unresponsive. Screens are getting greyed-out and I just can sit there and wait until the reading/writing is done.
This is not caused by the CPU which is overstressed because it is not. Look at the attachments and you will see the CPU is used for about 20%. When these pictures were captured the computer was using hellanzb to unrar a long list of rar-files.
When you look at my signature you see the computer is not bad at all, just disk-access is slow. I can transfer files with a maximum speed of 30MB/s. Is that normal or is it very slow? I don't know the numbers. I have 2 SATA disks.
O.S. is Mint 9-Isadora, based on Ubuntu 10.04 and I use the 64-bits version.
Am interested in using MT29F2G08AABWP NAND Flash memory for a new embedded design and I couldn�t find a clear specification regarding how reliable is the NAND flash vs. NOR for reading operation.If I program successfully a NAND block, read back and verify successfully the information and never erase or program that particular block again, can I assume that block will remain a good block and the information written there is safe for READING, roughly as safe as a NOR sector?
View 1 Replies View RelatedI just replaced a DVD-RAM drive in one HP server, The drive is recognized by the OS:
Code:
# lshw -class disk
*-cdrom UNCLAIMED
description: SCSI CD-ROM
product: DVDRAM GSA-T50L
[Code]...
Is there anything I should do when replacing a drive? Didnt think so, but this is going nowhere.
I just replaced a DVD-RAM drive in one HP server running CentOS5 (2.6.18-164.11.1.el5PAE #1 SMP )
The drive is recognized by the OS:
# lshw -class disk
*-cdrom UNCLAIMED
description: SCSI CD-ROM
product: DVDRAM GSA-T50L
[Code].....
I synthesized a seismogram by using Fortran codes, I need plot the synthesized seismogram and the data together, so I can verify the accuracy of code. Now I encounter a question: how to read the SAC data by Fortran code, I have searched some codes on Internet, the details as follow:the velr12a.sac is my data file.
Code:
c read sac file
PROGRAM RSAC
PARAMETER (MAX=1000)
DIMENSION YARRAY(MAX)
CHARACTER*10 KNAME
[Code]....
On a Linux CD/DVD, there are compressed filesystem images for the live version for KDE or Gnome for example, but they have no extension, but they are clearly an image file ( compressed filesystem images for the live version before installation ) !!
I was wondering, How do I mount these compressed filesystem images, after I copy the ISO content of the CD/DVD on my system .... I want to edit some files or packages and make some changes, like if I want to customize a live version of gnome for example ! ... ( I know you might be tempted to tell me to use KIWI etc to customize etc ..... ) ... but I want to be able to mount the compressed file system image, then edit it for reading and writing while it is in a subdirectory on its own ... i want to open it ! ... is there a way to do this ??? ... these type of files have no extension ...
i can open this compressed filesystem image then to edit for read & write ... before I roll it back again ..... If and when I succeed .... what should I watch out for ? ... will the same compressed file image but slightly modified work again ?
PS. that same question could be kind of translated or be extended like : how do I use unionfs/squashfs programs on the command line to mount these image files with no extension for read & write mode ???
I have a text file (myfile.txt) with columns a,b,c.
123 2 23
124 2 24
125 2 22
[code]...
Does anyone have some material about statistics using ubuntu / linux server, or a text which generally describes the ubuntu server?I need urgent, i'm writing specialization work about administration apache and ftp server on ubuntu 10:10 server, so I need something for the conclusion.
View 7 Replies View RelatedI don't understand the results of a simple performance test I ran using two basic scripts (running on a high end server):
perfVar.zsh :
#!/bin/zsh -f
MYVAR=`cat $1`
for i in {1..10}
[code]...
Performance test result:
> time ./perfVar.zsh BigTextFile > /dev/null
./perfVar.zsh FE > /dev/null 6.86s user 0.32s system 100% cpu 7.177 total
> time ./perfCat.zsh BigTextFile > /dev/null
./perfCat.zsh FE > /dev/null 0.01s user 0.10s system 91% cpu 0.118 total
I would have thought that accessing a VARIABLE was way faster than reading a FILE on the file system... Why this result ?Is there a way to optimize the perfCat.zsh script by reducing the number of accesses to the file system ?
i installed kernel 2.6.34 to fix my lid closing issue, and that went great. but now when i go to reinstall my broadcom i get this error. Code: Reading package lists... Done Building dependency tree Reading state information... Done bcmwl-kernel-source is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded. 1 not fully installed or removed. After this operation, 0B of additional disk space will be used. Setting up bcmwl-kernel-source (5.60.48.36+bdcom-0ubuntu3) ... Removing old bcmwl-5.60.48.36+bdcom DKMS files...
[Code].....
I am going to write a TCP server program using c. Can anyone give me some advices on whats and what not to do specially when using select?
There would be a lot of data to be transferred both on the server and back to the client. I already have a simple server here but the server uses a lot of resources. Maybe 3 to 4 connections and the server's load would rise to unacceptable levels.
Which do you think is better to use fork or select?
I have servers which contain SATA disks and SAS disks. I was testing the speed of writing on these servers and I recognized that SAS 10.000 disks much more slowly than the SATA 7200. What do you think about this slowness? What are the reasons of this slowness?
I am giving the below rates (values) which I took from my test (from my comparisons between SAS 10.000 and SATA 7200);
dd if=/dev/zero of=bigfile.txt bs=1024 count=1000000 when this comment was run in SAS disk server, I took this output(10.000 rpm)
(a new server,2 CPU 8 core and 8 gb ram)
1000000+0 records in
1000000+0 records out
1024000000 bytes (1.0 GB) copied, 12.9662 s, 79.0 MB/s (I have not used this server yet) (hw raid1)
[Code].....
I have/had a PC with several hard drives, and a mix of ubuntu and windows on multi boot.The old boot drive died screaming, and I need to start again. (But my data is safe! yay!)
Is there anything special about which drive can be the main drive to start booting from? Or to put it another way, can I install to any of the other 3 and expect it to work, or do I need to switch them around so a different drive is on the connections for the recently dead one?
I have running license server on my server. Right now I would like to write small status script and check if software is running.My software include 3 deamons:
1) daemonA
2) daemonB
3) daemonC
My script should check, if each of this deamon is running. If all deamons are running then script should print short output: "License server is running" if one of this daemons is not running, output should "License server is not running". Is it possible to write small loop to check it ? Let say, loop will take new daemon name from deamons pool and will check if its running. Sometimes I need to check more than three daemons of one Program and I dont know how to write good script for this. Maybe somebody could help me with this loop that in the future I could also use; daemonD, daemonE, daemonF.etc.etc. if all daemons from pool is running then..."Software is running"