Re: [Networker] Query in Staging from adv

Let me share some of my experiences regarding the X4500 performance as astoragenode with you.


We have recently made a benchmark with the following configuration:

- 8 NW clients with Sol.10, each connected with 1 GbE to a Cisco networkswitch- X4500 Sol.10 with 48x1TB disks as storagenode, with 6 RAIDZ pools (2disks for OS, 4 spares and 6 x (6+1) RAIDZ pools)

- each RAIDZ pool connected as AFTD, total netto usable 36TB out of 48
- Sun 10 GbE network card connected to the Cisco switch
- 2 dual-channel 4GbE FC HBAs connected to 4 LTO4 drives in a library

We tested the throughput in different B2D and B2D2T scenarios with thefollowing main results:- Filesystem backups from one client to one AFTD up to 75 MB/s (1GbElimited)

- 4 clients to one RAIDZ pool up to 200 MB/s
- 8 clients to all 6 RAIDZ pools up to 400 MB/s

- staging data from one RAIDZ pool to one tapedrive up to 140 MB/s (LTO4compressed limit here)

- staging data from 4 RAIDZ pool to all tapedrives about 400 MB/s

- mixed B2D and D2T from all pools around 400MB/s together (notrecommended as you can not really balance the R/W ratio)

- less than 50% CPU usage in all cases

As you can see, the practical performance you can get is about 400 MB/ssustained either read or write to the disks, assumed you can deliver thedata from the clients or consumed from the tapedrives. If only using theX4500 onboard 4 x 1 GbE interfaces as a trunk, don´t expect more than300 MB/s when doing backups.


Hope this helps a bit when setting expectations.

regards  -attila

--
********************************************************************
Attila Mester                           5 Digit Sun internal: x62534
Data Protection Architect                  Tel: (+49 89) 46 008 2534
Sun Microsystems GmbH                      Fax: (+49 89) 46 008 2583
Sonnenallee 1                                Mobil: +49 172 812 5947
85551 Heimstetten / Germany              mail: attila.mester AT sun DOT com
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Stan Horwitz schrieb:

On Aug 20, 2008, at 9:41 PM, Peter Viertel wrote:

Getting back to the subject at hand, one thing confuses me
about using
an ADVFS. We have a Sun X4500 with Solaris 10 as a storage
node that's
fibre channeled into a large tape library that's shared by our
NetWorker server. I routinely see speeds writing to that device of
around 70-90MB/s but usually when it dumps to Sony S-AIT1 tape, the
tape's throughput hovers around 45MB/s. While a staging
process is in
progress, no data can be recovered from the device. Our X4500 has a
1Gige line going into it, as does our NetWorker server.

I have two questions to follow up on what was said earlier.
Is 45MB/s
reasonable to write to tape and am I wrong in assuming that one can
never recover data from an ADVFS while its busy staging data
to tape,
or have I misconfigured this set-up?



Two answers for you, both leave us with questions however:

1. staging...

One thing we discussed a couple of months back was that if you are
restricting pools to devices - like you do when you have adv_file and
tape devices is that you need to make sure that both the real device and
the RO device are owned by the same pools. If you don't do this then
there will be contention between restores and cloning operations.

Or that was my recollection of this at least...   I have yet to sit down
with a test system and nut out the mechanics behind this - has anyone
else worked through the different configs?

2. AIT-1

I know nothing much about AIT - so I went looking on the sony website...
Here's what it tells me...   AIT-5 is the latest generation of this
technology - the drives can sustain data transfer rates around 80MB/sec
and they store 400G native - so these are roughly equivalent to LTO3.
you say you have AIT-1, the spec sheet says the tapes only store 40GB
native, the transfer rates is a measly 6MB/sec - which makes them the
equivalent of DLT8000, in other words AIT-1 drives should be in a
museum... If you're seeing 45MB/sec then either you've got later drives
and tapes than AIT-1, or the compressibility of your data is very good.

If you really do have AIT-1 drives then they are a mismatch for your
nice thumper system, if you want read-compatibility you can upgrade as
far as AIT-3T, it looks like AIT-4/5 can read 1...

I got all this from here.... http://sony.storagesupport.com/node/7176
I shall remain happy that we went with LTO.

I am using SAIT-1, not AIT-1. I routinely see 70-90MB/s on my tapedrives when doing direct backups (no advfs involved) for multiplesessions. The RO and writable parts of the advfs are both owned by thesame tape pool.

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Re: [Networker] Query in Staging from adv_file, X4500 experiences