Which do you prefer and why for HDD or SDD hard disks ? And how is Ext4 with power failures nowadays ? iirc a few years ago there were issues with Ext3 (Yes, Ext3) and I remember a no barrier option was needed ? Is Ext4 much better ? And what FS do you prefer on usb storage ?

  • @Echedenyan@lemmy.ml
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    13 years ago

    Don’t use rsync. I do them with Nextcloud or Syncthing and sometimes manually.

    For other cases, I use a manager for an Hypervisor for VMs to make programmed backups, also including snapshots.

    For me, an snapshot is a backup method.

    • Jakob :lemmy:
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      13 years ago

      BTRFS-snapshots only is no backup-method. Only if you send them to an external Store (external HD, SAN, NAS…) In case of deduplication and Copy-On-Write, a snapshot is physically the same store-location as the original. Only the few changed parts of the whole filesystem are stored on another physical place on the same HD.

      So if you use BTRFS-snapshots you MUST send/receive the snapshots to another medium, if you want to use snapshots as backup. Data-loss is so a big danger.

      • @Echedenyan@lemmy.ml
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        3 years ago

        I think you understand backup not as the real abstract concept but as a sub-class called “a secure way to make a backup”.

        If you copy a file to other folder to the same hard drive it is still a backup.

        The same happens with the btrfs-snapshots if the idea are for the files or changes you made in an Operating System installation (OpenIndiana with ZFS snapshots made for every system upgrade).

        • Jakob :lemmy:
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          23 years ago

          In BTRFS if you copy a File to another folder, only the reference is created. The physically information, what IS the file, is still the same. If you use [code]cp --reflink=always[/code] for sure.

          So if you make a Snapshot with BTRFS, it’s almost like a hardlink. The file disappears, when the last reference gets deleted. But al reference-files break, if the physically location on the HD breaks.

          So… making a snapshot in btrfs is not a backup for me. It is a good way for a fast rollback. It is a good way for deduplication. It is a good way for daily work. But a real backup for me is a physically separated store for the information.

          Make snapshots on a computer for fast rollback, or after system upgrade - even here for fast rollback. Or if I’m working on my photos, i do automatically every 10 minutes a snapshot. So a wrong command does only destroy the work of maximum 10 minutes… never the whole work.

          But backup… i make differential snapshots and send them with btrfs send/receive to another drive, so the snapshot is pyhsically duplicated on a separate store. One HD can break… i have a backup.

          Do you understand, what i mean?

      • @Echedenyan@lemmy.ml
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        3 years ago

        Maybe the example I gave was not enough.

        The point of snapshots is serving as some kind of incremental backups always dependent of a main backup or the main instance.

        Always the changes are copied, it is valid, even if a delta of a file was the only thing saved.

        This applies to systems with deduplication enabled and COW.