I guess the easiest way to estimate would be to take the total space a
client is using and divide that by the average tape utilization. That will
give tapes/client for each client. Then add them up.
One always figures at least one tape per client. That tape may never fill
for small clients thus resulting in less than optimum tape utilization. If
you have lots of small clients, the number of tapes you use with collocation
will likely be more than without. With lots of large clients, the effect of
poorly utilized tapes is somewhat less as only the last tape in a client's
"set" is partially full.
We suggest customers use collocation when they know they need to: restores
take too long without it. We also use collocation indiscriminately in the
case of moderately sized clients, large libraries and fast tape drives. The
though there is we might as well since, in general, collocation will provide
faster restores.
Kelly J. Lipp
Storage Solutions Specialists, Inc.
PO Box 51313
Colorado Springs CO 80949-1313
(719) 531-5926
Fax: (719) 260-5991
Email: [EMAIL PROTECTED]
www.storsol.com
www.storserver.com
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED]]On Behalf Of
Steven Fehl
Sent: Thursday, October 26, 2000 8:18 AM
To: [EMAIL PROTECTED]
Subject: Collocation - How many tapes will it use?
Hi,
I have a customer that has been running TSM for a little less than a year
without using collocation. I think it would be a good idea but I am
concerned
at how many tapes one of the clients will require.
Here are the specifics:
TSM Server: HPUX 11 TSM 3.7.1.0
Library: STK9710, 4 DLT7000 drives, 200 tape capacity, 35GB tapes
TSM Client: HPUX 11, TSM 4.1.0.0 with Oracle BCVs
Copy groups are set up with the following:
VERE 9999
VERO 9999
RETE 35
RETO 45
We are keeping about 35 copies of each file. I figured that if I checked the
occupancy for my largest client, I would be able to tell how many tapes I
would
use. The 35GB tapes are holding between 56GB and 128GB.
tsm: SERVER>select node_name, sum(physical_mb)/1000 as DATA_IN_GB,
sum(num_files) as "# of Files" from occupancy group by node_name order by
"DATA_IN_GB"
NODE_NAME DATA_IN_GB # of Files
------------------ -------------- -----------
INFOSYS21 0.96 13718
INFOSYS8 1.83 41592
DOORS13 2.33 35308
INFOSYS5 2.51 60222
DOORS10 3.23 82978
DBPRICEPROD 4.56 23800
DOORS8 4.70 39058
DOORS11 4.84 67474
BEECH 7.66 22124
DOORS12 8.72 25210
DBPRICEBKUP 9.47 20782
DOORSMF7 9.48 107822
DOORS14 9.53 55923
BASSWOOD 15.99 101924
MFLDSQL 39.31 238090
CEDAR 55.57 35278
DOORS1 84.78 311200
DOORS15 213.10 36848
DOORS0 286.55 801242
DOORSMF5 932.36 317944
DOORSMF4 1348.12 343154
DOORSMF6 8277.09 594222
tsm: SERVER>select count(*)as "Number of FULL
tapes",sum(est_capacity_mb)/count(*) as "Average Tape Capacity MB" from
volumes
where status='FULL'
Number of FULL tapes Average Tape Capacity MB
-------------------- -------------------------
109 112322.5
This seems to be telling me that I have 8,277GB backed up. At 112GB per tape
that would mean about 74 tapes.
Through another select statement and some UNIX utilities, I have found that
I
am using 61 tapes in the Primary Tape Pool and 63 tapes in the Copy Tape
Pool.
My question is, since it will take about 35 days for me to reclaim the old
not-collocated tapes, how many additional tapes will I need in the next
month
if I turn collocation on? I am backing up about 110 GB per night on this
client.
Although I have concentrated on my largest client, I do plan on collocating
all
my clients.
Thanks
Steve Fehl
=====
Steven Fehl
Sturgeon Bay, WI
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