PAC Brion Arnaud wrote: > > Your instructor should read his books again ...
The question wasn't about migration _processes_, but migration _threads_ internal to TSM. As you and Andrew both describe, there are multiple migration _processes_ kicked off in both cases. I hadn't heard anything about the "migrate stgpool" command running the migration processes all under a single thread (I don't know if that is even possible). So I looked at the (unsupported/undocumented) command "show threads" to see what I could find. I currently have 6 migration processes running, 4 initiated by reaching the migration threshold and 2 initiated by "migrate stgpool". Looking at the "show threads" output, I see 6 DfMigrationThread thread running. I checked earlier when no migrations were running and saw no threads of that type. So at a glance, it would seem the instructor is in fact incorrect. But if any TSM internals expert would like to offer a definitive answer, that'd be great. It would be unfortunate if "migrate stgpool" really was a lower performance method. > -----Original Message----- > From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED] On Behalf Of > Meadows Andrew > Sent: Tuesday, 27 November, 2007 21:01 > To: [email protected] > Subject: Mig stg question. > > Hello list. > > Environment . > TSM 5.3.4.1 running on AIX. > > I have a question about the mig stg command versus the hi/lo parameter > on a Disk Storage pool for migration purposes. > > I was recently in a TSM class and the instructor informed me that the > mig stg command runs single threaded as compared to the upd stg command > which will run multiple threads. > > Here is the theoretical situation I gave him. > > You have a disk pool. That is 10 GB. This disk pool has the Migration > Processes parameter set to 2. > Theoretically this disk is 50 % full with data from 2 nodes. And tyou > have the tape drives available for migration to the Next Storage Pool to > tape. > > Scenario 1. > > You issue the mig stg diskpool lo=0. > This will kick off 2 processes.... 1 per node.... > According to the instructor this is running on a single thread and > moving the data at a slow rate. > > Scenario 2 > > You issue the upd stg diskpool hi=0 lo=0 This will kick off 2 processes > .... 1 per node..... > According to the instructor this is running one thread per process and > moving the data in paralell. > > Has anyone seen this, or heard this? We are currently using the mig stg > command and I wonder if we could be doing this more efficiently. > > Thanks, > > > Andrew Meadows > Storage Services Operations > Enterprise Storage Services > HCA Information Technology & Services > -- Hello World. David Bronder - Systems Admin Segmentation Fault ITS-SPA, Univ. of Iowa Core dumped, disk trashed, quota filled, soda warm. [EMAIL PROTECTED]
