backups & cloning

Warren Block wblock at
Wed Sep 30 03:20:59 UTC 2009

On Tue, 29 Sep 2009, PJ wrote:

>>> $ newfs -U /dev/ad2s1a
>>> $ mount /dev/ad2s1a.... /target
>>> $ cd /target
>>> $ dump -0Lauf - /dev/ad1s1a  | restore -rf -
>> dump is reading /dev/ad1s1a and using stdout for output.
>> restore is writing to the current directory (/target) and is reading
>> from stdin.

> But what does that mean? But ad2s1a has just been newfs'd

No.  Exact details are extremely important here.  ad2 is the target, 
dump is reading ad1.

> And what exactly does stdout mean?  What is dump doing? outputting 
> what to where exactly? I don't see it or should I say, understand this 
> at all.and then the restore is from what to where?

The man page system is there to help you with this.  man dump and man 
restore show examples.  man stdout will help explain that.  Trying to do 
advanced operations without understanding these basics is going to be 
difficult, frustrating, and ultimately dangerous to your data.

>> A long pause while the system makes a snapshot is normal.
> And what's this about a snapshot? AFAIK, I'm not making a snapshot;

But you are.  That's what the -L option to dump means, as described in 
the man page.

-Warren Block * Rapid City, South Dakota USA

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