To be on the safe side, I would plan on 2:1 compression. You'll probably do
a little better than that in practice.
Below is a sample of some of our PC backup results from today. As you can
see, compression ratio varies a LOT. But we generally see at least 2:1
compression from a mixture of Win95 and WinNT 4.0 Workstations. Most are
primarily users of email, browsers, and the MS office suite, not any special
applications. (These are all ADSM Win32 client V3.1.0.6.)
Exceptions:
If a lot of the data is in .pst files (compressed mail files), they will not
compress well.
If a lot of the data is in .tif and .gif files, they may not compress well.
If a lot of the clients make heavy use of CAD/CAM, those files may not
compress well, either.
If I were you, I would pick a couple of the most "typical" clients, and back
them up to your current server as a test, even if you have to go across a
WAN and do it real slow. Then you can see for yourself what kind of
compression you'll have, before you get in any deeper.
04/25/2000 08:58:24 ANE4968I (Session: 7408, Node: ANDERFD1) Objects
compressed by: 38%
04/25/2000 08:58:44 ANE4968I (Session: 7395, Node: HORSTGM1) Objects
compressed by: 62%
04/25/2000 08:59:18 ANE4968I (Session: 7382, Node: DANZYL1) Objects
compressed by: 59%
04/25/2000 09:00:52 ANE4968I (Session: 7405, Node: POWERMM1) Objects
compressed by: 55%
04/25/2000 09:03:37 ANE4968I (Session: 7416, Node: GILLACL1) Objects
compressed by: 61%
04/25/2000 09:03:55 ANE4968I (Session: 7410, Node: BROWNSP1) Objects
compressed by: 67%
04/25/2000 09:07:22 ANE4968I (Session: 7429, Node: HICKSKY1) Objects
compressed by: 60%
04/25/2000 09:13:03 ANE4968I (Session: 7437, Node: HUGHECS1) Objects
compressed by: 55%
04/25/2000 09:15:16 ANE4968I (Session: 7433, Node: HILLSD1) Objects
compressed by: 51%
04/25/2000 09:20:22 ANE4968I (Session: 7443, Node: ANDERRC2) Objects
compressed by: 30%
04/25/2000 09:24:00 ANE4968I (Session: 7470, Node: KLEINSJ1) Objects
compressed by: 48%
04/25/2000 09:45:36 ANE4968I (Session: 7514, Node: STUARMW1) Objects
compressed by: 53%
04/25/2000 09:46:36 ANE4968I (Session: 7508, Node: BERGMSF1) Objects
compressed by: 59%
04/25/2000 09:48:40 ANE4968I (Session: 7522, Node: NIBECWL1) Objects
compressed by: 54%
04/25/2000 09:49:44 ANE4968I (Session: 7509, Node: FINKCR1) Objects
compressed by: 58%
04/25/2000 09:51:40 ANE4968I (Session: 7540, Node: BYRNEJB1) Objects
compressed by: 63%
04/25/2000 09:51:58 ANE4968I (Session: 7544, Node: STEWARC1) Objects
compressed by: 62%
04/25/2000 09:52:09 ANE4968I (Session: 7553, Node: SUNDEKW1) Objects
compressed by: 57%
04/25/2000 09:52:50 ANE4968I (Session: 7545, Node: BALLRE1) Objects
compressed by: 29%
04/25/2000 09:53:16 ANE4968I (Session: 7539, Node: HOWARKM1) Objects
compressed by: 24%
04/25/2000 09:55:06 ANE4968I (Session: 7548, Node: MCGONGM1) Objects
compressed by: 61%
04/25/2000 09:55:59 ANE4968I (Session: 7549, Node: MCCLACJ1) Objects
compressed by: 50%
Hope this helps.
************************************************************************
Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu
"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
************************************************************************
> -----Original Message-----
> From: Lawrence Clark [SMTP:Larry_Clark AT THRUWAY.STATE.NY DOT US]
> Sent: Tuesday, April 25, 2000 3:14 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: Guidlines for New *SM server
>
> Hi:
>
> We currently backup a mix of NT and RS/6000 servers to an AIX based ADSM
> server.
>
> Management has decided they now want to provide backup services for some
> 1200 PC clients, mostly WIN95. Since they are distributed sites we would
> probably go with distributed NT based ADSM servers that hold backup data
> locally on disk based storage pools.
>
> Does anyone have any experience with the likely compression we would
> experience, e.g., how much would 10 GB of pc data likely compress to on
> the NT storage pool?
>
>
> Larry Clark
> NYS Thruway Authority
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