Questions tagged [io]
I/O is an acronym for input/output, which refers to the mechanism or process for the transfer of information between one system or component and another.
646 questions
3 votes
1 answer
63 views
What is the best way to detect busy CPU cores for blk-mq request steering in Linux kernel?
I am trying to implement request steering in Linux kernel’s blk-mq layer to distribute I/O requests across CPU cores based on load. My goal is to redirect requests from busy cores to less busy ones to ...
- 31
0 votes
2 answers
127 views
when opening a FIFO for reading+writing, and blocking - how to tell if other side opened for reading or writing?
If I open a fifo for reading+writing in blocking mode: fd = open("foo", "O_RDWR"); Then it blocks until someone on the other end opens it for either reading or writing. But how do ...
- 117
2 votes
0 answers
65 views
dm-crypt IOPS amplification
I have a ZFS pool comprising a mirror comprising two partitions encypted with dm-crypt. $ zpool list -v data2 NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP ...
- 1,403
2 votes
1 answer
88 views
Which is better when using a program that produces output to STDOUT the program's output option or output redirection
Is there any advantage/disadvantage to using a commands output option (usually -o) if you can just use output redirection (>). Originally this question was specifically pertaining to cURL but after ...
- 23
1 vote
1 answer
448 views
Slow write operation on NFS volume
I have a problem on NFS volumes that appeared two days ago. The problem seems related to write operations, with the following taking a longer time (10s of seconds) to complete : sed -i rm Editing and ...
- 11
2 votes
1 answer
312 views
Automatic flush of stream when reading input
I read in Advanced Programming in Unix Environment this: Line buffering comes with two caveats. First, the size of the buffer that the standard I/O library uses to collect each line is fixed, so I/O ...
- 135
1 vote
1 answer
232 views
Understanding `pgpgin` in `/proc/vmstat` as I/O Counters: Relationship with I/O Bandwidth Measurements
Hi Kernel I/O Experts, I have a question regarding the pgpgin and pgpgout counters in /proc/vmstat, specifically focusing on pgpgin. I’ve been exploring performance monitoring tools like vmstat and ...
- 161
0 votes
0 answers
37 views
How can I get the _real_ progress of dd, ignoring fast/staging buffers? [duplicate]
I'm using the dd command to write to a USB stick. My command is pretty straightforward: dd if=myimage.iso of=/dev/sdd bs=1M status=progress and indeed, I seem to be getting the progress reported: ...
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