Date: Fri, 1 Oct 2021 00:48:36 +0100 From: tech-lists <tech-lists@zyxst.net> To: freebsd-questions@freebsd.org Subject: zfs q regarding backup strategy Message-ID: <YVZM1HnPuwIUQpah@ceres.zyxst.net>
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--boN+YW9GFVkJSx36 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, This is a bit chicken-and-egg for me, in that I might be formulating the wrong question, and so getting wrong answers, so I apologise in advance=20 if I'm being dense. Basically the end result I want is to be in a position at a backup site with full backups that can be restored to the live site if needed,=20 or even to get just one required file from that backup, given the filename= =20 and modification time. The backup site has very much more diskspace than the live site. I know how to make the full backup and to send it. What I'm looking for is incremental (or would it be differential) zfs backups (snapshots).=20 So let's say an incremental/differential backup to the remote site=20 happens every 6hrs. If 10 incremential backups happen after the full one, and on the live service someone loses a few files, later adding another few, maybe a couple of those have the same name as before just with a different modification time, all the while this is happening 24hrs pass. How are the accumulated differential/incremental snaps incorporated into the main backup? Would I need to run something else on the backup server to integrate the snaps with the full backup? Or would all=20 the snaps need to be kept?=20 How would one tell if the required files in this example are in one snap and not in the others? If the policy was to keep everything in backup regardless of whether it was deleted or not from the live service (so the backup is like a=20 write-only representation) I guess the approach would be different=20 to say if the backup just had to be the latest representation of the=20 data on the live server. But if it's "keep everything" then what happens if the live server makes foo.txt then deletes it then makes foo.txt 10 days later in the same place? All the while these (incremental/differential) snaps have been arriving every 6 hrs. Additionally the live site is the old zfs on releng/12.2-p10 and=20 the backup site is with the OpenZFS on stable/13 which might be an issue if they handle things significantly differently. thanks advance for any suggestions or any scripts/tools you can recommend. --=20 J. --boN+YW9GFVkJSx36 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE8n3tWhxW11Ccvv9/s8o7QhFzNAUFAmFWTMwACgkQs8o7QhFz NAUdHg/+IDQBKwdvpa9M1MpQcswefXin+QwdFJBhrcklnu84pWa2hVZvi/gLNJUe KIGvoTpRHQe8cGOiKoqJs7seazUp8IP7UN90h117feUKAZfBTqtWMl7IjyN4F05Z 9RhudykJ6YUIyVTzmXC/ZZOpaBTENaeIJkthofKekVKyMZhJ/35MBSfWno0GOqbS MzwNxk/g+vMIRHWRnZEB00DceCPwd6qYypnBFBNWojf6Bvc9V4S9muUTvO2ubUFL nr+7/2GqiJvKYC2rk/huYzjHdSR5gF50pEyENDWyw0MDNk6a44T9/ByZokVup3V3 oEUXcBIYlT+AaO93qJbHGZg6aj62l4JXZxX8h/MhuU5cn0WSw/YEI8btNN3m/SI9 L2o54MT3Eev0E1YDcSVuTqVdVdPzKCH82rkbY8jF39XkpVpQG+A9lMYAgMb0oJCM KrrrZ5NOMwqGr+jIZhDllIqTTTxrDDiWrjxdBo9irw5YeIg7OPilLBn4qzX7/If9 EAi0O9BTl2nGt75SkvpIAMcbLwj93CCocCPUDq9G3A5Bc7ww9gNELALHl0eZDIUa F/L5m99KWT+/L9w8n4ZdvWb7p+8JRieYRALMUOB4ee92+P+ogPCSzcLQa7e6uNzi hg9D5FERLbUrKRYVHwKAtyY2hIOFQS5ocdPtBMS0tMNGMQFhuLA= =1jSr -----END PGP SIGNATURE----- --boN+YW9GFVkJSx36--
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