Seems like the Linux style O_NOATIME flag (usable only by root - or on Solaris derivatives, possibly with a fine-grained permission) might be a useful addition to the OS, so that system programs that read a lot of files can avoid causing massive time updates that either generate excess I/O and obscure meaningful atimes, or have one mounting with the noatime option that makes them useless entirely.
Needless to say, programs like pkg would have to be modified a bit to use it on whatever they opened read-only that they didn't want to cause the atime to be updated on. I think there are some things like old fashioned style mail directories where one really needs atime updates; and over and above forensics or similar situations, there are a fair number of other cases where it might be useful, such as to find and possibly get rid of unused files in certain directories. > On Aug 21, 2021, at 07:36, Peter Tribble <peter.trib...@gmail.com> wrote: > > On Sat, Aug 21, 2021 at 10:32 AM James <l...@xdrv.uk> wrote: > >> On 19/08/2021 23:58, Carl Brewer wrote: >>> Further to this - is it worth disabling atime on the ZFS root pool >>> that's on the SSDs? I don't imagine it's a lot of data, but it would add >>> up over the years. >> >> Do you ever look at the access times? >> > > On some occasions, this is very useful - you can work out what > software installed is actually in use, and it's a way of detecting > unexpected things running. > > We turn it off at $WORK because of two things - we run pkg > verify every night, which means the access times are meaningless > because we read every file daily anyway, and we hold a lot of > regular snapshots and the atime writes end up consuming a significant > amount of snapshot space. > > -- > -Peter Tribble > http://www.petertribble.co.uk/ - http://ptribble.blogspot.com/ > _______________________________________________ > openindiana-discuss mailing list > openindiana-discuss@openindiana.org > https://openindiana.org/mailman/listinfo/openindiana-discuss > -- eMail: mailto:rlha...@smart.net _______________________________________________ openindiana-discuss mailing list openindiana-discuss@openindiana.org https://openindiana.org/mailman/listinfo/openindiana-discuss
