Run a pre- script on remote source? about btrfs-sxbackup HOT 5 OPEN

to elaborate why it's bad to do it remotely, you cannot reliably perform series of commands (lock -> flush -> backup -> unlock) as the connection may terminate in between and your lock may stay in place indefinitely.

if you need such logic, you can use a local script combining btrfs-sxbackup push job with anything else you need. simple and reliable.

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I didn't understand this. Do we already support pre/post scripts?

no. and it most probably won't be.

PS: except someone makes a good case for it, but I didn't hear any just yet.

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Good case of pre-post commands is flushing database caches to disk, for example in mysql:

1. SQL FLUSH TABLES WITH READ LOCK
2. Do the snapshot
3. SQL UNLOCK TABLES

We can do this via separate calls before and after btrfs-sxbackup, but with remote ssh connection it will require separate ssh connections and slows down the whole process.

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Good case of pre-post commands is flushing database caches to disk, for example in mysql:

imho it's not and it's usually bad practice to do so.
some databases can be configured to work well with (lvm or btrfs) snapshots and if it cannot, a filesystem snapshot tool is probably not the right tool for the job.

eg for mariadb you don't need flush when using innodb https://serverfault.com/questions/805257/backing-up-a-mysql-database-via-zfs-snapshots

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