[clug] fastest way to copy a fs

Tony and Robyn Lewis beakysnugger at yahoo.co.uk
Thu Jan 18 21:39:49 GMT 2007


Brett Worth wrote:
> What I normally do is and in initial rsync while the source filesystem
> is live then take it down and do a final rsync before cutting over to
> the new disk.  The first one can be done over a longer period and you
> can  lessen the load its putting on the source system with the --bwlimit
> option. The final rsync is the only one that causes downtime so makes
> the total downtime lower.  If I don't even want an outage to install the
> target disk for the initial rsync I do it with the target attached to a
> different machine.
>   

I'm not sure this is going to save you anything.  Each run of rsync is 
going to completely read both source and dest, in order to checksum all 
the chunks.  So unless your reads are significantly faster than your 
writes, you're not going to save anything in your downtime.

I could be wrong though...

Tony



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