Re: [Networker] Bootstrap and Index Question
2008-07-15 07:32:07
I will attempt to summarise all the options regarding index and
bootstrap backups, since it seems to be causing Bruce some confusion.
(1) Creating indices for backups (setting on pools called
"Store index entries"). This is nothing to do with backing up the
indices, just whether you have indices in the first place.
Pros: You will be able to restore individual files.
Cons: You will only be able to do save set recoveries unless you
later scanner the tape.
(2) When to save indices to tape?
* Immediately after backup (with original groups).
Pros: Indices backed up as soon as possible.
Cons: NW server may be mounting/unmounting tapes much more frequently.
If a client is in multiple groups you will backup its index
many times.
* At a later time using savegrp -O (may need to select
"no index saves" in group resource).
Pros: All indices backed up together - better for DR of server.
Cons: Delay in backing up.
Possible to omit adding a client to index group.
* Both immediately after backup AND later with savegrp -O.
Pros: Best of both worlds:
Cons: Uses more media than strictly necessary.
(3) Whether to use a dedicated index pool?
Pros: Server backs index up to a small number of tapes, minimising
mounts and unmounts. If you don't do this, all the pools need
to have volumes available on the server as well as the
storage nodes which means you will have very many
under-utilised tapes.
Cons: All eggs in one basket. If an index tape goes bad you may lose
many days of indices (can be overcome by cloning).
Note that if you are only using savegrp -O method, your indices will
go to one pool in any case, so this is unnecessary.
(4) Whether to backup your bootstrap with every group?
Pros: None.
Cons: Media DB locked while bootstrap backup in progress causing
potential backup failure.
If you are backing up bootstrap with every group your server is
probably mis-configured such that your NW server is not being
backed up. It could be that you are using an external scheduler,
in which case you probably need to schedule a dummy group
including the server to prevent this happening.
(5) Whether to suppress your bootstrap backups?
Trick question, because you can't actually do this from NetWorker.
However, there have been cases where a NetWorker server suffers many
backup failures due to the media DB being locked during a bootstrap
backup. This occurs when the NW server has many local backups to do. The
only way to stop the bootstrap backup is to replace the save command
with a wrapper script that selectively omits the bootstrap backup. This
is a very rare situation, but has happened.
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