rm -fr not deleting stuff

[Rashkae]

On 15-02-23 06:17 PM, Karl Auer wrote:
> Got a weird one here.
>
> Not entirely an Ubuntu question, but it is Linux. I have a Synology NAS,
> and I wanted to delete some old backup directories off it. I create
> backup directories using rsync, hard-linking to unchanged files in
> previous backups. This reduces the size of each backup by re-using an
> existing copy if a file hasn't changed. Read the man page for rsync and
> look at the --link-dest option.
>
> Anyway, when I tried removing a backup using rm -fr dirname it deleted
> heaps of files out of the directory and its many subdirectories, but
> also issued lots of messages about being unable to delete directories
> because they were not empty.
>
> I tries rsyncing (with --delete) an empty directory into the directory I
> wanted to delete, and rsync complained about being unable to remove
> non-empty directories as well. Oddly though, it seemed to be able to
> delete *some* of the directories that rm had not been able to remove. On
> a hunch I re-ran rm -rf on the directory, and it was 8also* able to
> remove some more directories, that botyh it and rsync had previously
> refused to delete! So I just ran rm -fr four or five times more and
> eventually it deleted everything including the topmost directory that I
> was trying to remove.
>
> So I tried on the next backup directory that I wanted to remove, this
> time just using rsync, and sure enough the same trick worked - I had to
> run rsync about five times, but eventually it removed everything.
>
> My googling suggests that a corrupted disk can have files that rm won't
> remove, but this disk is just fine. Nothing in the log files about
> errors, fsck says the disk is good, SMART says the disk is good.
>
> So I'm very puzzled. What would cause a directory to be not removed the
> first time through, but removed the second time through?
>
> Then I had a panic attack - what if it was the hard links? Maybe each
> time I did a rm, another link was removed? That would mean I had not
> just deleted the oldest backups, I had also deleted files I wanted to
> keep, that were hard-linked to in younger backups! So I checked - but
> even ancient files in the younger backups had been preserved - files
> that would certainly have been present in the older backups. Phew!
>
> But I am mystified. Any ideas, people?
>
> Regards, K.
>

The only thing I can think of is that rsync is copying directories 
without full permission. (directories missing the user execute or Write 
permissions)

Did you try your rm -rf with sudo?

I generally do my rsync backups without ownership or permissions (--no-o 
--no-g --no-p) to avoid these unintentional odd hiccups in my hard link 
directories.  If I need to preserve permission info from a source I'm 
backup up, I export those seperately with a getfacl -R > perms.file