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Re: Live Fille System Backup



On Sat, 06 May 2017, tomas@tuxteam.de wrote:
> Hm. That just means that the file will change after being copied.

There can also exist busy file *sets*, which need to be atomically
snapshotted (this is, of course, application specific).

"busy", as far as backups go, means:

1. a file changes [either in memory/buffer cache, or in the backend
   storage] *while* being copied (so it is internally inconsistent) --
   backup will have sections of the old file, and sections of the new
   file.

2. one or more components of a set of several files change *during*
   backup (files may be internally consistent, but the set of files
   itself isn't).

In some cases, (1) and (2) can manifest as files missing from the
backup, or being zero-sized.

-- 
  Henrique Holschuh


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