Rick I have a recent set up, TSM 6.3.4.300 on AIX 7.1, LTO5s and I too always thought that the atape driver did load balancing. However I have one port on each drive connected to one SAN and one port connected to a second SAN and I can see what port is being used because of which HBA the traffic goes down: in my environment I don't have access to the switches to be able to monitor there.
All of the TSM paths were defined using devices on the same SAN as I thought load balancing meant this would not matter. As it turns out the one I chose has a performance issue. Looking closer I saw that all the traffic was going down the devices as defined in the path, and none on the other SAN. When I rmdev-ed the device on the SAN with the performance issue, there was a message that the device had changed, the TSM path was updated to the alternate device (which I did not expect) and subsequent mounts have been on the alternate path. HTH Steve Steven Harris TSM Admin Canberra Australia On 14/10/2014 4:08 AM, Rhodes, Richard L. wrote: > What kind of drive are they emulating? Are they emulating IBM > drives with Atape driver? My understanding (I've been trusting > this for years) will auto load balance across hba's. > > Rick > > > > -----Original Message----- From: ADSM: Dist Stor Manager > [mailto:ADSM-L@VM.MARIST.EDU] On Behalf Of Erwann Simon Sent: > Monday, October 13, 2014 12:36 PM To: ADSM-L@VM.MARIST.EDU Subject: > Re: Load balancing when you have many virtual tapes? > > Hello Wanda, > > As TSM allocates drives in order, you have to distribute drive > between the HBAs in a round robin way (with 4 hba : drive 1 on hba > 1, drive 2 on hba... drive 5 on hba 1 and so on). I prefer doing > this at VTL level using mapping policy (i.e access groups on Data > Domain). > > Le 13 octobre 2014 18:28:36 CEST, "Prather, Wanda" > <wanda.prat...@icfi.com> a écrit : >> TSM 7.1.1 on AIX So I have a customer putting in a VTL, which >> will have 96 virtual drives. Those virtual drives will be spread >> across 4 HBA's. >> >> What sort of strategies to people use to keep TSM from starting >> a BACKUP stgpool process and picking 4 virtual drives all on the >> same HBA? Is it dependent on the order you do your DEFINE DRIVE >> commands? Better to set up multiple virtual libraries? >> >> Any suggestions appreciated. >> >> Wanda >> >> >> Wanda Prather | Senior Technical Specialist | >> wanda.prat...@icfi.com<mailto:wanda.prat...@icfi.com> | >> www.icfi.com<http://www.icfi.com/> | 410-868-4872 (m) ICF >> International | 7125 Thomas Edison Dr., Suite 100, Columbia, Md >> |443-718-4900 (o) >