how to know if noatime or relatime is default mount option in kernel?
Solution 1
This should list all the options a file system was mounted with:
cat /proc/mounts
Solution 2
This question is pretty old, but you can look at default mount options for an ext filesystem with:
tune2fs -l /dev/<device>
Solution 3
nfsstat -m
will give you a listing of all NFS mounts and flags.
With that said, I had to use cat /proc/mounts
on an older 2.6.5 kernel, since nfsstat -m wasn't supported then.
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user368507
Updated on September 18, 2022Comments
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user368507 over 1 year
I was trying to know if relatime or noatime was set on a filesystem, but i didn't found the information, neither in /etc/fstab, neither in kernel boot options.
First of all, it seems clear that i don't have the "normal" behaviour on atime:
root@antec:/tmp# rm -f test.txt; echo a>test.txt root@antec:/tmp# stat test.txt | \grep -i 2011 Access: 2011-08-01 21:54:30.000000000 +0200 Modify: 2011-08-01 21:54:30.000000000 +0200 Change: 2011-08-01 21:54:30.000000000 +0200 root@antec:/tmp# cat test.txt > /dev/null root@antec:/tmp# stat test.txt | \grep -i 2011 Access: 2011-08-01 21:54:53.000000000 +0200 Modify: 2011-08-01 21:54:30.000000000 +0200 Change: 2011-08-01 21:54:30.000000000 +0200 root@antec:/tmp# date Mon Aug 1 21:55:00 CEST 2011 root@antec:/tmp# cat test.txt > /dev/null root@antec:/tmp# stat test.txt | \grep -i 2011 Access: 2011-08-01 21:54:53.000000000 +0200 <--- atime not modified Modify: 2011-08-01 21:54:30.000000000 +0200 Change: 2011-08-01 21:54:30.000000000 +0200 root@antec:/tmp#
I have two questions:
- Is noatime or relatime a default mount options, and if yes, from which kernel release ?
- Is there a way to see the default mount options (ie: how can i see why i don't have the "normal" atime behaviour ?)
Many questions but i think they are related. Feel free to edit the title if you have a more explicit title.-
Admin almost 13 yearsmaybe ask at serverfault.com
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Admin almost 13 yearsthanks. I see that "mount" does not show everything! Do you know where do the "additionnal" mount options (ie: those shown in /proc/mounts but not in /etc/fstab) come from ? I mean, where the kernel reads them ?
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Clarus almost 13 yearsThe kernel contains the default values appended as file system options if no particular value is specified. The exact values of the default options are contained in the kernel config when you compile the kernel.
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Admin almost 13 yearsgoogle returns nothing on "CONFIG_ relatime" and
grep -i relatime .config
returns nothing on my machine. What did i miss ? -
Clarus almost 13 years
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Admin almost 13 yearsThe link talks about a "CONFIG_DEFAULT_RELATIME" kernel option, but i cannot find this option, it is not in the kernel sources (I have check in 2.6.36 and 3.0), neither in my .config. I don't understand why CONFIG_DEFAULT_RELATIME does not exist in the kernel sources
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underscore_d over 8 yearsAnd how would someone install that program, since it does not appear to be a standard inclusion?
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Peter Hansen over 8 years@underscore_d use "apt-get install e2fsprogs" or the appropriate local equivalent.
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Csaba Toth almost 8 yearsOr just type
mount
without any parameter, that's gonna basically do acat /proc/mounts
but it's a nice shorthand.