If you are running on Solaris, there is a known issue (starting in 7.5.x) that
is causing slowdowns in all cloning. The release notes stated this, on page
46...
>
> Solaris 9 users who upgrade from NetWorker 7.2.x may notice errors during
> cloning operations
> LGTsc07111
> Customers upgrading from 7.2.x may notice errors similar to the following
> during
> cloning operations:
> 38758 11/27/08 16:21:45 2 0 0 1 23334 0 <hostname> nsrd media
> warning: /dev/rmt/0cbn writing: posix async write: Error 0
> 42506 11/27/08 16:21:45 2 0 0 1 23334 0 <hostname> nsrd media
> notice: LTO Ultrium-4 tape 64U00S00 on /dev/rmt/0cbn is full
> 42506 11/27/08 16:21:45 2 0 0 1 23334 0 <hostname> nsrd media
> notice: LTO Ultrium-4 tape 64U00S00 used 89 MB of 800 GB capacity
> Workaround
> These issues may be related to a Solaris operating system limitation. If you
> experience these errors, disabling asynchronous I/O capability may resolve the
> problem.
> To disable async I/O capability:
> 1. Shut down NetWorker
> 2. Set the DISABLE_SOL_ASYNC_IO environment variable in the NetWorker
> startup script. The default location of the startup script is
> /etc/init.d/networker.
> 3. Re-start NetWorker using the NetWorker startup script
> Note: With Async I/O disabled, performance impacts may be noticed during
> cloning
> operations.
>
> Slow performance on Solaris 10 because asynchronous I/O is disabled
> LGTsc24548
> Due to a Solaris 10 operating system issue, asynchronous tape input/output
> operations are disabled by default. As a result, some I/O intensive
> operations such
> as cloning will be slower.
>
--TSK
Eileen Su wrote:
> Some interesting things:
>
> 1. I did some tests by creating another Networker v7.3.3 server, adding
> some adv_file devices and a storage node. When I run cloning from the
> server to the SN through network, the speed is about 26.6 MB/s.
>
> 2. I upgraded the server to v7.5.1, but leave the SN unchanged, run
> cloning again, the speed dropped to 18MB/s.
>
> 3. Upgraded the SN to v7.5.1, so both the server and the SN are in v7.5.1.
> Run cloning again, the speed is even lower, 15.2MB/s.
>
> So cloning in v7.5.1 is denifitely slower than in v7.3.3.
>
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