From: Marco Atzeri <marco.atzeri@gmail.com>
To: cygwin@cygwin.com
Subject: Re: tar incremental backups and ctime problem
Date: Mon, 23 May 2016 15:35:00 -0000 [thread overview]
Message-ID: <b2009993-f09a-c07f-f524-34266334c151@gmail.com> (raw)
In-Reply-To: <CAOKAGPOVnU1Lr2od-UbtRAeZHFKjnNC2jOmmGouVotSYMxbokw@mail.gmail.com>
On 23/05/2016 16:57, x y wrote:
>> mtime is fakeable, ctime is not. Using only mtime makes it likely that
>> your incremental backup will miss files. I don't have any good reason
>> to differ from upstream behavior here.
>
> Hi Eric,
>
> The problem is not faking time stamps. Even commercial Windows backup
> programs are checking the modification time to identify the modified
> files.
>
> Consider that you have a lot of files opened and closed without any
> modification in your company. Because of the priority of the ctime
> time stamp, reintroducing all of those files to the incremental backup
> does not make any sense. tar has also the capacity to create
> differential backups with the condition of taking care of the snapshot
> file. The ctime issue can result in unnecessarily big differential
> backups filled with unmodified files.
>
> Cygwin tar can be a good alternative for Windows users to do
> differential \ incremental backups but the ctime problem must be
> solved.
>
It is always possible to create file list with find and use that
to tar whatever using --files-from=FILE option
I don't see the need to change tar behaviour to meet your wish.
Regards
Marco
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next prev parent reply other threads:[~2016-05-23 15:35 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-23 8:40 x y
2016-05-23 8:47 ` Marco Atzeri
2016-05-23 8:54 ` x y
2016-05-23 9:06 ` Marco Atzeri
2016-05-23 9:18 ` x y
2016-05-23 14:29 ` Eric Blake
2016-05-23 14:57 ` x y
2016-05-23 15:24 ` Vince Rice
2016-05-23 15:35 ` Marco Atzeri [this message]
2016-05-23 16:56 ` x y
2016-05-23 19:02 ` Eric Blake
2016-05-23 17:19 ` Erik Soderquist
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