I know about this because I got bitten by it. I realize it's working as designed, but I think the design bites. Intuition tells me that if you collocate by group, any node not in a group doesn't get collocated. But that's not the way it is.
-- Mark Stapleton ([EMAIL PROTECTED]) IBM Certified Advanced Deployment Professional Tivoli Storage Management Solutions 2005 IBM Certified Advanced Technical Expert (CATE) AIX Berbee Information Networks Office 262.521.5627 >-----Original Message----- >From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On >Behalf Of Kolbeinn Jósepsson >Sent: Thursday, October 13, 2005 9:22 PM >To: ADSM-L@VM.MARIST.EDU >Subject: Re: Group collocation > >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" <[EMAIL PROTECTED]> >Sent by: "ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> >14.10.2005 01:39 >Please respond to >"ADSM: Dist Stor Manager" <ADSM-L@VM.MARIST.EDU> > > >To >ADSM-L@VM.MARIST.EDU >cc > >Subject >Re: Group collocation > > > > > > >Zoltan Forray/AC/VCU <[EMAIL PROTECTED]> >>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:[EMAIL PROTECTED] 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 ([EMAIL PROTECTED]) >IBM Certified Advanced Deployment Professional > Tivoli Storage Management Solutions 2005 >IBM Certified Advanced Technical Expert (CATE) AIX >Berbee Information Networks >Office 262.521.5627 > > >