CentOS - Feb 2022 - Any downside to mount -o noatime?

On Thu, Feb 10, 2022 at 05:32:05PM -0800, Kenneth Porter
wrote:
>--On Thursday, February 10, 2022 8:03 PM -0500 Matthew Miller
><mattdm at mattdm.org> wrote:
>
>> relatime has been the default for a long time -- that only updates
atime
>> once per some reasonable timeperiod. The wear and tear from that is
>> negligible and you can still get a basic idea of when files where
>> accessed.
>
>According to the man page for mount, relatime updates atime whenever mtime
>or ctime are updated, or if neither has been updated in the last 24 hours.
>Which is still prohibitive if you're doing an incremental (rsync) backup
>and checking file contents on the "full" backup weekly or monthly.
>
>The only apps I've found that need atime are tmpwatch and biff, neither
of
>which I use.
atime updates that occur when {m,c}time are updated add
no additional burden.

So you are concerned about a single "possible" inode update
once a day?

jl

-- 
Jon H. LaBadie                  jcu at labadie.us

--On Thursday, February 10, 2022 8:49 PM -0500 Jon LaBadie <jcu at
labadie.us>
wrote:
> atime updates that occur when {m,c}time are updated add
> no additional burden.
Understood. If that's the only time it happened, I would be happy with that.
> So you are concerned about a single "possible" inode update
> once a day?
I'm using BackupPC to do rsync-based backups of all my systems. The 
"incremental" backups look only at size and timestamp changes. The 
less-frequent "full" backups checksum all my files. That means an
extra
write for every file that gets checked.

I'd love to have a version of relatime that only did the first kind of 
update, when ctime or mtime changed but not when 24 hours had passed.