[Moosefs-users] Fwd: Fwd: Backing up MFS metadata

[Stas O. <sta...@gm...>]

Hi.

After reading the "Metadata files ins and outs" article, and this email
thread, I'm still left with several questions that I would like to clarify:

1) Does mfsmaster dumps to checkpoint files an up-to-date representation of
the memory, at periods of 1-2 minutes maximum?
Meaning, backing up the /var/mfs directory and restoring it back, will
provide me with a 1-2 minutes maximum of data loss?

2) Does metalogger pull an up-to-date version of master checkpoint files as
well? If I move the master to metalogger and restore the checkpoint files,
it will provide me with a 1-2 minutes maximum of data loss as well?

3) Any benefit of lowering the default 24 hours download frequency? Or the
streamed updates from master to metalogger will be enough?

4) In case I do want to backup to external storage (NAS for example), which
would be the better source machine - master (sounds more logical) or
metalogger?

5) If I have 3 metaloggers for example, how much load it will incur on the
master server?


Thanks in advance for answers, as it would clarify the backup topic for me
completely!

Regards.