From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Masover Subject: Re: snapshot, checkpoints Date: Wed, 09 Jun 2004 17:21:58 -0500 Message-ID: <40C78D86.2060305@slaphack.com> References: <20040527065259.99429.qmail@web51306.mail.yahoo.com> <1085641393.1915.199.camel@tribesman.namesys.com> <20040527092727.GO4990@nysv.org> <20040604131005.hmvps8wcw4sccgcs@www.wagland.net> <200406041925.i54JPZgp025255@turing-police.cc.vt.edu> <40C14E9C.4000706@slaphack.com> <116CD3CA-B709-11D8-A933-000A95CD704C@kungfoocoder.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <116CD3CA-B709-11D8-A933-000A95CD704C@kungfoocoder.org> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Paul Wagland Cc: reiserfs-list@namesys.com, tdwebste2@yahoo.com, Vladimir Saveliev , Markus TXrnqvist , Valdis.Kletnieks@vt.edu -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Paul Wagland wrote: | At least with LVM, and therefore I assume with device mapper, the | "snapshot" only stores changed blocks. From what I understand, this | means that when you take a snapshot, if you change a block in the | original, it first copies it to the snapshot, and then writes the new | block to the original system. Of course, you will run into a problem if | more changes are made than the snapshot partition size, but AFAIK it | then just disables the snapshot. Good, then we don't have to immediately rewrite the wheel. But I still would rather that we do this eventually. My concept has the changes stored on the same partition, seems like it may be faster, and opens the door for a filesystem-based cvs. Think about that! I mean, if copy-on-capture is what I think it is, then things like 'cp' could be extended to copy using a system call (similar to how 'ln' works). Probably a few utilities would have to be extended, but the net result is, you don't have to say you're doing something in a cvs dir for it to be cosidered a cvs action (just do 'cp' instead of 'cvs cp' or whatever). You don't "check out" different versions, you just look in different folders. (I'm using 'cvs' in the generic sense -- could work as easily for bittorrent or anything else.) -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iQIVAwUBQMeNhngHNmZLgCUhAQLe6w/+I5Emoxp6pLDA+9Ncd7UK0ZSkQsT0lwqu jofkphMJ6hKZhE4KSB5IYup7Xh2ZqUZu1v+9gj0d/tLHatpCfLLklZJn0gKRA9+f wUBY5VD18VmuWO0Zhi1R7QGAzijCThvyJTmhlu56E6dXEaQTxu7OufLmwfGDFgeT LN3I/diPXVPp4AihzeFqT7F3/cYQgK/6wYgx9kB8QWsq9qcRzXY1XghuPgyoWJ9Y AtIFmHmKLu9vP2S0mh7u6sv9R1UlzwdKZhpdxESytMqOV1m1xQbLdi5wLkS37i9l Y9oxuhXXjiK+bkEwwdr+7/Ide1CzaRDthlBUMT+jy+zKekQLRLJtiZi3IhZeRb6V UbO5SmHUqTxBltMEmp5zDMTX7QtT+n663GQCBzepMX55u9VWGTKrGYuSxDeJF5T7 5BT+FZ/UtY9ONL3hFFzMwAtaiI4r7rEIx0t2R1TVhsUhV69KmUXs4A2I0WOXPG4i wFIQAjyX6BQtP3nn1QKIfeqpTRSHO2wPBC8dEAL8fFiiEBh/HEQdbbWCVCD3hj7G 0iNoLvL6w3qfPG+rRZtRdIn0apyd4zus0vWNpWWT8jh/QUeHGp97kzoEP3MQUlYk kyVdFgwiX63l1AtJh6MWTDA2iVvegiaCY9Uuna5H77yJkV7uw8vc+TfRGRiq2otU N7AQvJK8OBU= =Nr9u -----END PGP SIGNATURE-----