Hello,

maybe someone could explain this to me. I'm curious about the three
different times the ls command shows to me. What I've learned from the
man page so far is:
ls -lu -- shows time of last access
ls -lc -- shows time of last modification of the inode

so, this is clear for me. But what time shows the ls -l command?

f.e.:
#ls -l xxx.html
-rw-rw-r-- 1 woma test 9886 Jun 23 16:17 xxx.html
#ls -lu xxx.html
-rw-rw-r-- 1 woma test 9886 Jul 17 08:32 xxx.html
#ls -lc xxx.html
-rw-rw-r-- 1 woma test 9886 Jul 11 13:15 xxx.html
#

And which time would be important for a incremental backup

Thank you

Wolfgang

Wolfgang Mair wrote:
>
> Hello,
>
> maybe someone could explain this to me. I'm curious about the three
> different times the ls command shows to me. What I've learned from the
> man page so far is:
> ls -lu -- shows time of last access
> ls -lc -- shows time of last modification of the inode
>
> so, this is clear for me. But what time shows the ls -l command?
>
> f.e.:
> #ls -l xxx.html
> -rw-rw-r-- 1 woma test 9886 Jun 23 16:17 xxx.html
> #ls -lu xxx.html
> -rw-rw-r-- 1 woma test 9886 Jul 17 08:32 xxx.html
> #ls -lc xxx.html
> -rw-rw-r-- 1 woma test 9886 Jul 11 13:15 xxx.html
> #
>
> And which time would be important for a incremental backup
>
> Thank you
>
> Wolfgang


Hi,

three timestamps exist for a file :
- the "atime" : time the file was last accessed (typically read)
- the "ctime" : time the file was last changed (i.e. datas in the file were changed)
- the "mtime" : time the inode of file was last modified : datas were changed (i.e. mtime and ctime are changed together) or inode was changed (changing owner, group, permissions, ..., changes the mtime.

Backup tools are usually based on mtime, which one can easily understand as mtime reflects all possible changes made to a file.

Be careful : some tools, as Netbackup, change mtime when backuping (by default, NBU saves atime and mtime, then backups the file - which modifies the atime, as backup is a read operation - and then restore the atime and mtime to the file, which modifies the ctime ...). Such a behaviour can be changed using the following options in bp.conf :

USE_CTIME_FOR_INCREMENTALS
DO_NOT_RESET_FILE_ACCESS_TIME

Hope tis helps,
Anthony

In <HI5v3J.GH7@approve.se> hoh@invalid.invalid (Goran Larsson) writes:

> Wrong, this is "mtime". The "ctime" is when file status was last
> changed. Changed by the following functions: chmod(), chown(), creat(),
> link(2), mknod(), pipe(), unlink(2), utime(), and write().

acl()