Something else I'd like to add since the discussion moved this way a bit...
If you use the cp -rp command for a recursive copy, the owner and group are not preserved as they are set on the target side to the user who is doing the copy. Also, mtime is set to "now" on the target side. However, if you want to preserve owner, group, perms, and mtime on a copy you can do the following as root: cd /source find . -depth -print | cpio -pdm /target 1) You must hand cpio the filenames to be copied using a relative path (.) 2) For decades find did not have a default action of -print, so I still put it there out of habit. 3) You need -depth so that find starts at the bottom of the filesystem tree and works its way back up. This makes it so that cpio will set mtimes on the directories back to what they had in /source 4) The -p option on cpio is pass-through. It does not build a backup/archive file, it does a copy. The -d option is to make sub-directories as needed, and -m maintains mtimes from source to target. I used this a lot when moving directories in / into their own new filesystems after a system had been installed, say /opt, again as root: mount /dev/whatever /mnt cd /opt find . -depth -print | cpio -pdm /mnt cd / du -sk /opt /mnt <== /mnt should be slightly larger than /opt due to the /mnt/lost+found directory that was not in /opt since it is a part of / rm -rf /opt/* <== remove everything inside of /opt to free up space in the / filesystem, but leave /opt the directory for the mount point umount /mnt mount /dev/whatever /opt vi /etc/fstab <== or /etc/vfstab, or /etc/filesystem depending upon OS; and add an entry to mount /opt at boot time. Dan On Sun, May 28, 2023 at 9:25 AM Paul Boniol <[email protected]> wrote: > P.S. If you're willing to ignore matching mtime, there is a --size-only > parameter. > > On Sun, May 28, 2023, 9:17 AM Paul Boniol <[email protected]> wrote: > >> Funny you should mention rsync. That's what I'm using to copy recent >> files. >> >> You have to run root (sudo) to so some things (like preserve >> user/group/mtime). And in my case, to not get nagged about not being able >> to change user/group it needs user map and group map parameters. (Shouldn't >> be necessary going to ext4.) >> >> What I ended up choosing was >> sudo rsync -avc --usermap=*:paul --groupmap=*:paul source-dir dest-dir >> >> Obviously do n for trial run till you're sure. >> >> The checksum option obviously takes quite a while for it to start, but >> not choosing checksum, rsync wanted to copy every file, regardless. I'm >> guessing some difference in mtime storage? Idk. The user and group mapping >> were the last thing I set so possible it was something with that. >> >> ---Paul. >> >> On Sun, May 28, 2023, 7:56 AM Howard White <[email protected]> wrote: >> >>> I have struggled with a similar problem. I have directories of mp3 >>> files in two places: ntfs and ext4. With the demise of iROCK109, I need >>> to resolve all of the ntfs files as the master copied to the ext4 (on my >>> NAS) which I share in the house. rsync is messing with me over >>> permissions. >>> >>> Howard >>> >>> On 5/28/23 03:21, Paul Boniol wrote: >>> > Way back, I should have paid more attention... but I have like 3 TB of >>> > video recordings backed up to an external (exfat) hard drive (should >>> > have reformatted as ext4 first but I didn't think about it first). >>> > >>> > Now I'm preparing to do a fresh Linux install. And I'm wanting to >>> > somehow backup the user/group/permissions for the directories and >>> files. >>> > >>> > I can look and write them down as most would be the same. Just >>> wondering >>> > if there's some better way. >>> > >>> > ---Paul. >>> > >>> > -- >>> > -- >>> >>> -- > -- > You received this message because you are subscribed to the Google Groups > "NLUG" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/nlug-talk?hl=en > > --- > You received this message because you are subscribed to the Google Groups > "NLUG" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/nlug-talk/CAL9PgS1x3tG5%3DwBYi0%2BAg88mVXVX3q9pzb-Czyqw0SATBxU7gQ%40mail.gmail.com > <https://groups.google.com/d/msgid/nlug-talk/CAL9PgS1x3tG5%3DwBYi0%2BAg88mVXVX3q9pzb-Czyqw0SATBxU7gQ%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- -- You received this message because you are subscribed to the Google Groups "NLUG" group. 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