Re: Group collocation
2005-10-13 22:24:19
My apologizes, Mark you are correct!
The best practise should be to use at least two seperate storagepools, the
first with collocation=no (where all non-collocated nodes belongs to) and
the second with collocation=group (where nodes in collocaton groups
belongs), you can then chose if you use the second pool also for
collocation by node (non grouped nodes) or if you add the third stgpool
with collocation=node (and perhaps the fourth stgpool with
collocation=filespace if your environment is "large enough").
Best regards,
Kolbeinn
"Stapleton, Mark" <mark.stapleton AT BERBEE DOT COM>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
14.10.2005 01:39
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Re: Group collocation
Zoltan Forray/AC/VCU <zforray AT VCU DOT EDU>
>If I take a storage pool and change it to GROUP from NO
>collocation, what
>about the data for nodes that ARE NOT in collocation groups ?
>Does their
>data get collocated or not ? Will I all of a hsudden go from 1-2 daily
>LTO2 mounts to 30 ?
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On
Behalf Of Kolbeinn Jósepsson
>Only data from nodes in collocationgroup will be collocated, data from
>other nodes in same stgpool will not be collocated.
This is incorrect. My experience has been that, when setting a pool to
"collocation by group", that any node not belonging to a collocation group
will get its data to that pool collocated.
(from page 312 of the TSM 5.3 for Windows Administrators' Reference)
====
GRoup
Specifies that collocation is enabled at the group level for client nodes.
The server attempts to put data for nodes that belong to the same
collocation group on as few volumes as possible. If the nodes in the
collocation group have multiple file spaces, the server does not attempt
to collocate those file spaces.
If you specify COLLOCATE=GROUP but do not define any groups, data is
collocated by node. Similarly, if you specify COLLOCATE=GROUP and you
define a group but do not add nodes to the group, data is collocated by
node.
===
The workaround I found is to create collocation groups and populate them,
then create one more collocation group that contains all other nodes that
write to that storage pool that are *not* already in a group.
--
Mark Stapleton (stapleton AT berbee DOT com)
IBM Certified Advanced Deployment Professional
Tivoli Storage Management Solutions 2005
IBM Certified Advanced Technical Expert (CATE) AIX
Berbee Information Networks
Office 262.521.5627
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