Re: Supermicro X8DTH-6: Only ~250MiB/s from RAID<->RAID over 10GbE?

[Julian Calaby]

On Mon, Feb 7, 2011 at 09:01, Stan Hoeppner <stan@xxxxxxxxxxxxxxxxx> wrote:
> Justin Piszcz put forth on 2/6/2011 4:16 AM:
>
>> Workflow process-
>>
>> Migrate data from old/legacy RAID sets to new ones, possibly also 2TB->3TB, so
>> the faster the transfer speed, the better.
>
> This type of data migration is probably going to include many many files of
> various sizes from small to large.  You have optimized your system performance
> only for individual large file xfers.  Thus, when you go to copy directories
> containing hundreds or thousands of files of various sizes, you will likely see
> much lower throughput using a single copy stream.  Thus if you want to keep that
> 10 GbE pipe full, you'll likely need to run multiple copies in parallel, one per
> large parent directory.  Or, run a single copy from say, 10 legacy systems to
> one new system simultaneously, etc.
>
> Given this situation, you may want to consider tar'ing up entire directories
> with gz or bz compression, if you have enough free space on the legacy machines,
> and copying the tarballs to the new system.  This will maximize your throughput,
> although I don't know if it will decrease your total work flow completion time,
> which should really be your overall goal.

Another option might be to use tar and gzip to bundle the data up,
then pipe it through netcat or ssh. When I have to transfer large
chunks of data I find this is the fastest method. That said, if the
connection is interrupted, then you're on your own. rsync might also
be a good option.

Thanks,

-- 
Julian Calaby

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