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Questions tagged [io]

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

272 questions
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3 answers

Linux: Is there something similar to "top" for I/O?

My disk often is utilized, but top (and htop, a custom replacement) show nothing suspicious. Is there a way to sort processes by I/O (more specific: disk) utilization? EDIT Found out using iotop that those strange processes are flush-8:16 and…
java.is.for.desktop
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60
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4 answers

How do I find out what processes are accessing the hard disk in a GNU/Linux-based system?

I'm looking for the equivalent to top for disk access, so I can tell which process(es) are currently reading and/or writing to disk. I'm currently using Ubuntu, but I imagine there's a standard tool that's available as part of the GNU toolset.
Olivier Dagenais
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52
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5 answers

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 specifying a specific process (-p pid), I get all…
Mark Ebbert
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36
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4 answers

How to change I/O priority of a process or thread in Win7?

Process Explorer is able to show the effective IO priority of a given thread, but not change it. Seeing as IO priority support is a comparatively new feature, most programs don't set their own IO priorities. It appears that by default the IO…
RomanSt
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1 answer

Full list of top-like tool family for perfomance monitoring in linux: iftop iotop htop atop more?

Top-like utilities are extremely handful in my work and I want to make sure I am not missing any of them. Please extend the following list of performance monitoring (top-like) family of linux tools: top - original tool htop - adds support to…
Yauhen Yakimovich
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32
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3 answers

Are there any Pros/Cons to the /j Robocopy option (unbuffered copying)

Robocopy has a /J command line option recommended for copying large files (it copies using unbuffered I/O). What (if any) downsides are there? Any reason this isn't enabled by default? (That's what made me think there MIGHT be downsides.)
Clay Nichols
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29
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4 answers

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, 75, or 100 percent, even though there's scarcely any…
ecapstone
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26
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3 answers

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 there any reason many architectures use both?…
user291288
25
votes
3 answers

Task Manager shows 100% disk usage at just 0.5Mbps

My PC shows 100% disk usage though Task Manager lists down only 0.4Mbps as the total usage and the PC freezes. At other times, I can see disk I/O going upto 7 Mbps, but PC does not freeze. I have drilled down into Resource Monitor as well, but I…
user1880957
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23
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1 answer

diagnosing 100 percent disk usage in windows 10

Since updating to win 10, I'm experiencing issues with my disk usage. From time to time (sometimes every 10 minutes, sometimes once every few hours) my system becomes unresponsive because the disk usage is 100%. It usually takes one or two minutes…
klmdb
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20
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4 answers

Should I store my code/projects on my SSD or my secondary drive?

I just got a new box. It has an SSD for the primary drive and a 1TB SATA hard disk for the secondary drive. I'm going to run Windows OS and my binaries on the SSD and keep all my downloads/documents/music/etc on the secondary drive. My question…
fr0man
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2 answers

How to monitor which files lots of data is being written to on Linux?

I can monitor I/O with tools such as iotop. It allows me to identify which processes do how much I/O. Now I'd like to know which files those processes write all that data to. How would I do that? E.g. something like "ok I know Tomcat is doing a lot…
Johannes Ernst
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13
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3 answers

Debugging Linux I/O latency

I'm having some I/O problems on a couple of Linux systems that I administer. They manifest in that processes often block for up to several seconds in such simple syscalls as open(), unlink() or close() on files (which is a problem because some of…
Dolda2000
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11
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2 answers

When a disk read or disk write occurs, where does the data go?

I understand that there is such a thing as a disk controller which contains a buffer, but was wondering if the CPU reads directly from this buffer, or whether the data must first go to a specific location in memory, and then allow itself to be read…
Kaitlyn Mcmordie
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Is it bad if millions of files are stored in one NTFS folder?

I have a very large NTFS volume with more than 20TB capacity and containing millions of files. If I put all of the files in the same folder, I know the performance is bad when I open the folder in Windows Explorer. Is the performance still bad if I…
flypen
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