Messages in this thread | | | Date | Mon, 19 Jan 1998 11:27:17 -0500 | From | John Kodis <> | Subject | Atime behavior. Was: Re: 3.0 wishlist |
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On Mon, Jan 19, 1998 at 10:00:05AM +0100, Mikael Abrahamsson wrote:
> I would like to be able to set noatime as a mount option so I can > choose what filesystems I want noatime on and not.
Rather than just setting atime to on or off, it would be useful to allow an atime delta, to specify how accurate an atime value was required. For example, if a file system were mounted with adelta=86400, the atime value of the files on this file system would only be updated if the current atime value is more than 86400 seconds (i.e., one day) ago.
This would avoid the need to perform an inode write each time a file is accessed, while still providing a good indication of which files can be safely rolled off to a tape archive after having not been accessed for 6 months. Setting adelta=1 would yield the current behavior, and adelta=0 could be interpreted as 'no atime'.
VAX/VMS provided such a capability, so there's some past practice with such a scheme. On VMS, IIRC, the adelta value was settable on a file-by-file basis, with newly created files inheriting a default from their parent directory. Given the current inode space shortage, this would have to wait for ext3. However, providing this feature on a file system basis seems like something that could be added to the existing no-atime code fairly easily.
-- John Kodis.
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