interpreting iostat output

I'm running mojave on a macbook pro

If i run

iostat -d -c 3

from the command line, I get

disk0 disk2 disk3 disk4

KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s KB/t tps MB/s

40.58 43 1.69 17.56 0 0.00 24.95 0 0.00 25.60 0 0.00

0.00 0 0.00 0.00 0 0.00 0.00 0 0.00 0.00 0 0.00

How do I map the disk numbers shown above to actual devices?

MacBook Pro 15″, macOS 10.13

Posted on Nov 28, 2020 8:57 AM

Similar questions

What apps are doing I/O on external disks I am running Mohave 10.14.6 on a Mac Mini. At times, I see the I/O lights flashing excessively on my G Drive disks. I know that I can tell if MacOS is indexing those disks by using Spotlight, but when Spotlight does not show indexing, I don't know how to determine what is causing all the I/O. I have explored Activity Monitor but that does not specify which disks are being accessed. Is there a Bash UNIX command or shell script that will display which apps or processes are accessing specific disks?
444 1
How to measure individual disk activity...? Hi all, I have one internal HDD, "Macintosh HD". I also have some external drives that are used for Time Machine backup. I would like to measure disk activity per disk. That is, I would like to be able to see what the "data" and "io" activity is that Activity Monitor report but per disk (Activity Monitor gives a cumulative average across all devices). I am happy to use the Unix shell command set. Just throw it at me. Actually, I'd prefer to have the detail that the good ol' Unix shell commands provide. Thanks in advance,
953 7
Can I know which process is using the kernel ? Hi, every morning at around 8AM my Mac connected to my NAS for about 1hr, using the disk like crazy. I have tried to understand which process is doing what, but despite I was using instruments or Activity Monitor or Little Snitch, in the end I can only understand the following: data is transferred from the IP address of my Mac to the IP address of my NAS using NFS the process involved is kernel (id 0) whose ppid is launchd (id 1) Of course, this is not enough because I would like to understand which process is invoking the kernel system calls to access the disk. Is there any tool that can help me? Wireshark tells me which files are accessed (read, mainly), but of course it doesn't tell me who is doing that. The NAS (with iotop, for instance) shows me nfs is the main process using disk, but I cannot go any further. So basically I am blind and so far, what I used just tells me what I already see by myself. Any help would be appreciated. Thanks! Luca
502 8

1 reply

BDAqua

Level 10

250,259 points

Nov 28, 2020 10:55 AM in response to red_wood

In Terminal...

diskutil list

This thread has been closed by the system or the community team. You may vote for any posts you find helpful, or search the Community for additional answers.

interpreting iostat output

Welcome to Apple Support Community

A forum where Apple customers help each other with their products. Get started with your Apple Account.

Learn more Sign up