Re: [Networker] cloning/backup speed in a w2k environment

On Mon, 14 Apr 2003 13:24:38 -0400, Michael Brooks
<michaelb AT SEQUOIAINS DOT COM> wrote:

>w2k networker server, sp2
...
>adic scalar 100 jukebox w/two ibm ultrium lto drives
>backing up 4 w2k servers, sp2, and one hp-ux 11 server
>
>we are getting ~3mb/s on backups, and ~1.5mb/s cloning. the drives are
>rated at 15mb/s, and we have the nics set at 100mbps/fd.
>

Hi Michael,

your performance figures don't look very impressive ... :-(

We use LTO-1 in an W2K (SP3) environment as well, but
do not (or not that much) LAN backups.
So we get 10-25MB/sec to one LTO-1 (hw-compression on).
(depends on application, client power, etc.)
Cloning performance is normaly 10-13 (have not seen 15
that often).

With 100mbps you can expect 7-8 MB/sec, if the
LAN is switched (or has not to route other traffic).
Slow down (on the client side) will occur, if you are backing up
fileservers with thousends (millions) of very small files
(typical: office, profiles, etc.) and deep directory trees.
Anyway, the 100mbps-link will never stream one LTO-1.

So I would recommend the following:
- Use 100mbps on clients, but (if ever possible) a 1000mbps
  on the server.
- backup multiple clients at the same time to ONE drive
- use client side compression to get more over the wire
 (o.k. there are some guys here, which do NOT recommend to
  use client side compression if the tape has not enough data
  to "stream")
  (but "client side compression" is always a good choice if
   the savesets will be cloned later)
- for cloning (assumed the two drives are local) you should
  see 10MB/sec
- use "bigasm" to make some local/remote performance tests
  (local to tape, remote to disk, remote to tape)
- keep your Ultrium drivers up to date
- do not "daisy-chain" LTO-drives on one adapter
- ...


Hope this helped a bit. Steffen
--
Steffen Gattert; MOMENTUM Systech; Hamburg

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