Once upon a time, Valeri Galtsev galtsev@kicp.uchicago.edu said:
On 4/3/20 8:34 AM, John Pierce wrote:
Do note, backup systems that use rsync or similar file by file copies of a running system do not make coherent atomic snapshots, so things like relational databases should be excluded from those, and backed by database tools
Long ago I learned to back up databases by dumping them (with a flag "lock" or similar to make sure no changed are made during dump), and backing up dump file.
It isn't just databases - there are other things that backing up individual files one at a time is not so good. The best way to handle that is to freeze/snapshot the whole filesystem, and then back up the snapshot. This can be scripted pretty easily if the filesystem is on LVM.
Even better is to freeze _all_ filesystems simultaneously - this is usually easiest if the system is a virtual machine and/or the storage is on a SAN with snapshot capabilities.