IO or I/O is a common shorthand for referring to Input and Output

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What is I/O? How does it affect PC operation? [on hold]

I see this I/O abbreviation a lot, what does it mean? How does it affect Computer operation?
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How Memory Mapped I/O works in x86 architecture?

If we use "mov" instruction between the address range of "0x000A0000 - 0x000BFFFF",how cpu understands that the data will be going to video card memory not to main memory?
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28 views

Memory Mapped vs I/O Mapped Input Output

I'm currently reading a computer organization book and i'm so confused about Input/Output mechanism and have lots of questions in my mind. As i understood there are two concepts for communicating ...
0
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0answers
28 views

NFS writes to md-raid extremely slow with busy jbd2

As far as I can remember, this problem appeared after upgrade from Debian Squeeze to Wheezy. The symptom is extremely slow write performance on the server's dmraid exclusively if written via nfs ...
2
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1answer
61 views

ls -l but not ls --color=never slow on nfs-mounted directory, if simulatenously writing to that directory

when I dump data into an NFS-mounted directory, reading files modes (e.g. ls -l) is several orders of magnitude slower than a plain file listing (e.g. ls --color=never). I would like to understand ...
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30 views

Monitor disk I/O used by specific command

I know that there are various tools for monitoring disk I/O, but I am wondering specifically if there is something equivalent to time for disk usage? For example, I am benchmarking a specific command ...
2
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1answer
30 views

Windows: Wide Variation in Read Performance

I'm new when it comes to measuring i/o performance. I found a tool called HDTune Pro, which according PCWorld is a good tool for i/o benchmarking. This tool attempted to read 40GB, on the first ...
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1answer
19 views

How can I debug IOZONE over the network?

I'm working on a mac and I have a vm running ubuntu server. I created a file vm_client.iozone that looks like: vm /path/to/test /usr/bin/iozone I have configured iozone to work over ssh using ...
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2answers
104 views

hard drive - How type of I/O access influences access time?

I am trying to better understand how the type of I/O access influences the access time. Can a conventional HDD perform both random and sequential access ? If so why would you want to keep provisions ...
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2answers
43 views

How is it possible for me to hear the audio of multiple different videos on my computer? [closed]

I am reading this book and so far, being in chapter 3, I understand that multiprogramming and multiprocessing allows for faster execution of multiple existing processes/threads. I am reading into all ...
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3answers
52 views

Find which process uses on average the most CPU, Memory and IO on Windows 7

I'd like a way to monitor processes on Windows 7 for average CPU, Memory and IO since last boot. I would love it if it was a nice UI friendly tool that could sort processes by Average CPU, Average ...
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0answers
59 views

Can anyone assist me in determining why my ssds are running so slowly please?

I have an MSI GT 680 Gaming laptop that I use for data analysis work. History: Originally I had a pair of 128GB Kingston Hyper X SSDs in the system in RAID 0. I put these in place (when I bought the ...
2
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1answer
224 views

Why does synchronizing 1.4 TB of data with my Dropbox account result in over 28 TB of IO read?

I tried to sync 4.4 millions of files (totaling ~1.4 TB) with my Dropbox account. I noticed a pretty high amount of IO read (28 TB) when the files were being synchronized, is there any reason why? ...
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0answers
99 views

Thinkpad Yoga “Disk I/O Error” (Linux)

My machine is sporadically remounting the SDD readonly due to a "Disk I/O Error". This seems only to happen when I connect to the laptop to a power source or after resuming from suspend. The SSD ...
0
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1answer
108 views

Mac SSD freezing & I/O error

6 months ago I've added a SSD (Samsung 840 Pro 512GB) on the back of the superdrive and enabled TRIM. It's still as fast as it was when I bought it. Since some days my mac randomly freezes twice a ...
6
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1answer
7 views

Writing to subfolder is faster than writing to its parent

I use dd to measure write perfomance and observed something strange: writing to /data/emzed2 is faster than writing to /data. This is the way I measured the performance: $ dd if=/dev/zero ...
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44 views

limit/cap total disk I/O to temporarily improve Windows stability on faulty hardware

Is there a way to limit/cap total disk I/O on a Windows 7 system? Processes like git and McAfee sporadically crash with InPageError (for files on different physical drives), seemingly most often when ...
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42 views

List contents of zip archive via stdin

Is there a "magic" way to list the contents of a Zip archive piped in via stdin? For instance: $ some_process_sending_files_in_one_zip_stream_to_stdout | gunzip -l - ... listing of files ... When ...
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1answer
457 views

Linux BFQ Scheduler with SSD

In the past I had always been advised by resources that I can get a performance boost when using SSDs by switching from the default Linux scheduler CFQ to one such as deadline or noop. Today after a ...
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1answer
38 views

Converting multiple files using programs that accepts stdin and output to stdout

I want to convert a list of files in a directory to another directory using some preprocessing programs. I know I can do this for one file: cat "$INDIR/$file" | ./program > "$OUTDIR/$file" And ...
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1answer
51 views

How long does it take for Linux to drop caches?

I run the following to clear cached files from the filesystem/system memory: # echo 3 > /proc/sys/vm/drop_caches I'd like to do this on a scripted basis, so that when I do I/O testing to compare ...
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78 views

Understanding iotop

I have a postgresql select query that consumes only 12% CPU, and little to no memory, but it still takes about a minute to run. I immediately tried to check the IO, using iotop. Sure enough, in ...
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1answer
193 views

Optimal cluster size for random I/O

I'm specifically interested in the answer for NAND storage (SD cards, memory sticks). I have a Windows 7 laptop where I run 2 VM's inside VMWare, as well as multiple programs in the host OS. VM disk ...
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171 views

Redirect output to console I/O on IAR Embedded Workbench

I have coded a project of mine in C on a Windows machine in the software IAR Embedded Workbench IDE. The project compiles and runs fine. I have a couple of printf functions in my code. But the thing ...
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1answer
129 views

How to lower I/O priority for file copying operations under Linux Mint?

Whenever I copy files from a disk to another on my personal Linux system, the OS stops responding appropriately, the UI starts behaving erratically, any movies I'm playing will freeze and continue ...
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1answer
78 views

i/o Bus Standards & Device Controllers

I'm really confused about bus standards like ide,ata,sata,pci etc. I have just read this article :When a disk read or disk write occurs, where does the data go? So if we talk about hard disk drive; ...
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1answer
40 views

Why do subsequent reads of a multi-gigabyte file run faster?

I have some algorithm test software running on a Windows 7 machine which, when run the first time on any given data file, runs ~3-5x slower than on subsequent runs. Our algorithm simply reads the file ...
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60 views

Can random writes to a non-formatted raw partition from linux corrupt the boot loader?

In brief: suppose I create a non-formatted raw partition on my hard drive, and read and write block IOs to and from it using the standard c interface: open, pread, pwrite, etc. Is there any reason why ...
3
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1answer
3k views

Difference between port mapped and memory mapped access?

Can anyone explain what's the difference between port mapping and memory mapping, and what having both accomplishes? Why is there port mapped, how does it differ in structure from memory maps, and is ...
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8 views

OSX tilts on creating new dirs, allows new files on external drive

I've an external drive that was working fine until this morning. Now, I'm able to create new files (with copy, touch whatever), but I can not create/move new directories. Any ideas? $ mount ...
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3answers
98 views

What is consuming my disk?

I have a Win8 64bit Dell XPS One computer that continuously has trouble operating because the disk I/O is at >99%! I need a way to find out what is causing this. The Task Manager is no help because ...
4
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1answer
162 views

No performance increase on I/O intensive operation after symlink to ramdisk

We have a system that transforms a set of several thousand multi-MB files. After every step in the transform, it writes the intermediate file to disk. The concept is similar to a scratch disk. We ...
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110 views

circumvent directory I/O error

I recently recovered a large amount of data from a failed external hard-drive with ddrescue, which did an excellent job. However, after running the tool several times and with different options, it ...
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1answer
30 views

Windows 7 printing “io” infinitely in all focused input areas

A few weeks ago, my computer started doing this strange behavior. All I did was click into a window that allowed for user input and the computer began printing "io" over and over again (no error, but ...
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4answers
213 views

How can RAM contain a “memory map” if RAM is unaware of the overall system?

This question concerns hardware more than software. Basically, citing from this article on memory maps, it says that: In computer science, a memory map is a structure of data (which usually ...
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1answer
887 views

Keep getting i/o error 1117 while trying the file operations

I am trying to copy a huge file (around 50 GB) to external hard drive. I keep getting the I/O error. I tried all things compressing the file, trying to copy to same drive splitting the file using ...
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1answer
594 views

<1MBps 4K read/write HDD issue

I bought a netbook, Windows Starter - it seemed really slow right from the start, so I removed all the bloatware, but it remained slow still. So I tested disk I/O with CrystalDiskMark and got 4k ...
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269 views

Getting i/o statistics of a process per file

I have a process of I would like to monitor the i/o with some precision. I know the PID, but I can't really control the way it is started (so I can't really put a pv-like command in between). What I ...
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7answers
687 views

Do computers need any input or output device?

Somewhat inspired by an answer I gave about keyboard lights I now ask this: do computers actually need any sort of input (keyboard, mouse, touchpad, scanner, microphone, joystick, etcetera) or output ...
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1answer
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High Disk I/O and CPU usage of System Process in “System Volume Information”

I've a problem with high disk IO and cpu usage from the system process. With the performance monitor I can see that it writes and reads about 100MB/s froM "System Volume Information". I tried to get ...
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4answers
467 views

how much does “chown -R” affects disk IO performance? how can I test it?

I'm running a Cent OS server with a NAS storage. I have heard "rm" command makes overall disk IO slow. So, I gave up doing rm -R. I will do rm one by one with a shell script. --EDIT--> rm and sleep ...
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1answer
112 views

Windows are unresponsive for a few seconds after boot (probably IO error with HDD)

When Windows is loaded and I am logged in into my desktop, the system gets unresponsive for about 10-15 seconds. During this time, the HDD led indicator at the case is either flashing or on (solid). ...
2
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66 views

Windows 7 keyboard input hangs while reading from usb hard drive [closed]

There is a strange behavior of windows 7. I like to listen to music while coding (surprising), so I always carry with me my usb storage and play music from it. Sometimes while playing a song it kind ...
2
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1answer
267 views

What does “Disk active time” mean in task manager?

I've read online that "disk active time" means something like the amount of total time the disk spends on IO activity. I'm kind of confused about what that means. Also, on a virtual machine, what ...
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1answer
141 views

I/O error when burning Windows OS to DVD from Image Burn tool

I get the error message below from Imageburn when I try to burn Windows OS to a blank DVD. I want to know whether the cause might be the DVD writer or something else? I tried two blank discs. But I ...
2
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1answer
279 views

iotop complains “CONFIG_TASK_DELAY_ACCT not enabled in kernel” only for specific process

I'm trying to use iotop to determine whether the CPUs are waiting on I/O at any point for a specific program called bwa (it's a next-generation sequence alignment program). If I start iotop without ...
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1answer
155 views

How does the number of files in the same folder affect I/O performance in an ext4 filesystem

I'm using Kyoto Cabinet (a key-value store) for my project. The specific type of DB I'm using is DirDB which creates a lot of files in a directory to store the key-value pairs. The server I'm running ...
2
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2answers
1k views

Windows 8 System.exe writes to HDD like crazy

I have checked Application event logs and found that every second about 20 entries for MSSQL Server were recorded. Removed the server and all its components and the problem is gone... Thanks everyone ...
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1answer
447 views

How to to measure and monitor I/O performance

We have a linux cluster with worker nodes sharing a common remote file system. We want to optimize the I/O, in particular when the workers read from the remote fs. The starting point is to measure ...
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4answers
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Windows 8 extremely high disk usage and slow IO

Problem After upgrading from Windows 7 to Windows 8 Professional, there seem to be a few disturbing problems. When I have the Task Manager open, I sometimes notice the disk usage climbing to 50, ...