What type of drives are you emulating ? How many drive are simultaneously used in full charge ? What is the highest throughput you need ?
Anyway, you are obliged to define 16 drives by HBA... >From my point of view, I will make the most simple choice : HBA1 : drv1, drv5, drv9, and so on HBA2 : drv2, drv6, drv10, ... HBA3 : drv3, drv7, drv11, ... HBA4 : drv4, drv8, drv12, ... > -----Message d'origine----- > De : ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] De > la part de Mcnutt, Larry E. > Envoyé : jeudi 23 août 2007 16:05 > À : [email protected] > Objet : Re: [ADSM-L] How does a library choose a drive? > > Hi Pierre, et al. > > We are in the process of adding a new VTL to our TSM server, > and we are trying to understand if there is a way to > configure the drives that will spread the I/O load across the > available fcsi ports. The AIX server has 4 4GB fibre > connections to the VTL appliance. We are emulating a Quantum > P3000 library with 64 drives. When we initially configure > the library with all 64 drives, they are divided across the 4 > fibre ports with port 1 having drive1-drive16, > port2 drive17-drive32, > port3 drive33-drive48, > port4 drive49-drive64. > > We thought this may not be an optimal setup if TSM uses a > round-robin algorithm. So, we recreated the configuration. > This time we defined 16 drives initially, which were then > spread across the 4 fibre ports with port1 drive1-drive4, > port2 drive5-drive8, > port3 drive9-drive12, > port4 drive13-drive16. > > Then we went through the process 3 more times until we had 64 > drives defined. This results in the having the drives > defined across the 4 ports as: > port1 drive1-drive4, drive17-drive20, drive33-drive36, drive49-drive52 > port2 drive5-drive8, drive21-drive24, drive37-drive40, drive53-drive56 > port3 drive9-drive12, drive25-drive28, drive41-drive44, > drive57-drive60 > port4 drive13-drive16, drive29-drive32, drive45-drive48, > drive61-drive64 > > This seems like a better configuration for a round-robin > drive assignment. It was at this point that we thought we > should try to learn how the drives are assigned. > > Thanks for any suggestions or pointers. > > Larry > > -----Original Message----- > From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] > On Behalf Of CAYE PIERRE > Sent: Thursday, August 23, 2007 5:36 AM > To: [email protected] > Subject: Re: How does a library choose a drive? > > Hi, > > From my observations, it depend of the action TSM is doing. > > For example, when TSM is in initialisation state, there is a > validation of all the drives, in element addresses order. > When TSM is doing an audit libr checkl=y, it work the same > For that cases, and others, concerning ALL drives, TSM seems > to act in element adresses order > > BUT when doing recurent task, as backup and so, TSM SEEMS to > act as Richard explain, asking the OS for a drive, so it's > the OS which make the choice, based on it own algorythm. > > Larry, what are the reason why you want to know that point ? > > Pierre > > > -----Message d'origine----- > > De : ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] > De la part > > de Kelly Lipp Envoyé : mercredi 22 août 2007 20:56 À : > > [email protected] Objet : Re: [ADSM-L] How does a > library choose a > > drive? > > > > I'm with Paul: TSM chooses the drive and based on my observations > > always does round robin. Not LRU as I don't think it keeps > track of > > that. So it will choose the next drive in order as long at > that drive > > isn't in use. If in use, skip to the next and keep going around. > > > > You see this on label libvol commands in particular. > > > > > > Kelly J. Lipp > > VP Manufacturing & CTO > > STORServer, Inc. > > 485-B Elkton Drive > > Colorado Springs, CO 80907 > > 719-266-8777 > > [EMAIL PROTECTED] > > > > -----Original Message----- > > From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] > On Behalf > > Of Paul Zarnowski > > Sent: Wednesday, August 22, 2007 12:00 PM > > To: [email protected] > > Subject: Re: [ADSM-L] How does a library choose a drive? > > > > Sorry to disagree, but I don't see how AIX can choose the drive - I > > believe that TSM chooses it. I don't know if it's LRU or > round-robin, > > but I do know that it attempts to spread the load evenly. > > > > At 01:56 PM 8/22/2007, Mcnutt, Larry E. wrote: > > >Thanks Kelly, Richard and Andy for the quick responses. So, as I > > >understand it in my scenario, it is the AIX host that > > chooses the drive > > > > >that is the "least recently used" one. At the very > > beginning, it will > > >start at the first drive and sequentially go through them > > all and then > > >it will begin picking the "least recently used" drive to > > keep the usage > > > > >spread evenly across all the drives. > > > > > >-----Original Message----- > > >From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] > > On Behalf > > >Of Andy Huebner > > >Sent: Wednesday, August 22, 2007 12:26 PM > > >To: [email protected] > > >Subject: Re: How does a library choose a drive? > > > > > >"Least Recently Used" I think is the management level > explanation of > > >how it is done. > > > > > >Andy Huebner > > > > > >-----Original Message----- > > >From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] > > On Behalf > > >Of Richard Sims > > >Sent: Wednesday, August 22, 2007 10:57 AM > > >To: [email protected] > > >Subject: Re: [ADSM-L] How does a library choose a drive? > > > > > >On Aug 22, 2007, at 11:32 AM, Mcnutt, Larry E. wrote: > > > > > > > TSM Server 5.3.3.0 > > > > AIX 5.3 > > > > > > > > This is probably not a TSM specific question, but > > hopefully someone > > > > can point me to the right place to look. > > > > We would like to understand how the library decides which > > available > > > > drive to use. ... > > > > > >It doesn't decide: the host determines which drive to use. > > >TSM uses them rotationally, to balance wear. > > > > > >For a 3494 library, see the MTIOCLM (Library Mount) library > > system call > > > > >in the IBM SCSI Device Drivers Programming Reference for the > > >nitty-gritty. For a SCSI library, where the host has to > > engage in more > > > > >intricate control of library mechanics, I believe it's the > > >SMCIOC_MOVE_MEDIUM call (Transport a cartridge from one element to > > >another element). > > > > > > Richard Sims > > > > > > > > >This e-mail (including any attachments) is confidential and may be > > >legally privileged. If you are not an intended recipient or an > > >authorized representative of an intended recipient, you are > > prohibited > > >from using, copying or distributing the information in this > > e-mail or > > >its attachments. If you have received this e-mail in error, please > > >notify the sender immediately by return e-mail and delete > > all copies of > > > > >this message and any attachments. > > >Thank you. > > > > > >----------------------------------------- > > >This message and any attachments are intended for the > individual or > > >entity named above. If you are not the intended recipient, > please do > > >not forward, copy, print, use or disclose this communication > > to others; > > > > >also please notify the sender by replying to this message, > and then > > >delete it from your system. The Timken Company / The Timken > > Corporation > > > > > > -- > > Paul Zarnowski Ph: 607-255-4757 > > Manager, Storage Services Fx: 607-255-8521 > > 719 Rhodes Hall, Ithaca, NY 14853-3801 Em: [EMAIL PROTECTED] > > >
