My compatriot Chris Gibson highlighted a great performance tuning attribute for Fibre Channel adapters in this blog post . I was so excited that I dusted off my blog-writing skills (much neglected) and got fired up enough to put Chris' advice into practice via a script. First, the advice - which came originally from IBM's Dan Braden - is to display the number of command elements - num_cmd_elems - on a Fibre Channel adapter. num_cmd_elems? Huh? On AIX (and on the Virtual I/O Server) there is an attribute on Fibre Channel... [More]

Tags:  fc dan chris gibson fibre aix chdev channel queue adapter num_cmd_elems technote performance depth disk braden

"Go live or go home" If you need to get a lot of data from one AIX host to another, there's more than one way to do it quickly. During a migration to a new system, you may do a database dump or archive and want to get the data available to the new LPAR within a short time frame. You can tweak the network settings improve your SAN configuration (just turn on the turbo switch) and assign more resources to ease the bottlenecks. Of course there's Live Partition Mobility (LPM) and various High Availability options but they may not be... [More]

Tags:  bus varyoffvg exportvg logging copy importvg rsync jfs varyonvg ethernet adapter san lun high virtual speed data nolog

NOW FOR THE I/O I highlighted some of the excellent AIX performance tuning resources here . They particularly dealt with memory and paging space. Now to I/O tuning. Fewer larger LUNs and checking queue_depth Jaqui Lynch has the follow up article in her two-part performance tuning series. This one's on Disk I/O and Network Tuning . She deals especially with queue_depth and explains why one great big LUN with lots of spindles may need to have this tuned: The trend in the industry right now is to provide fewer, larger hdisks to the server. For... [More]

Tags:  fcstat tuning vmstat iostat memory fibre queue_depth adapter disk sat performance i/o channel aix lvmstat

MEET MIN, MAX and DES When you create an LPAR (Logical Partition), you have to create a profile to specify the processors, memory and I/O slots you want to allocate. I’m going to focus on memory right now, and specifically what the minimum , desired and maximum memory settings mean. You’ll see that the memory allocation can change while the LPAR is up and running using Dynamic LPAR (DLPAR) and DLPAR's can only go as low as min and as high as max. Makes sense, doesn't it? This is about setting up LPARs that use dedicated memory . I’m not... [More]

Tags:  paging_space active_memory_sharing profile shutdown dedicated_memory memory vios adapter activate required desired hmc partition active_memory_expansion minimum lpar hardware_management_conso... maximum aix

In September 2009 Rob McNelly wrote on his AIXChange blog about Migrating from the IVM to the HMC . I have documented my own experience of this procedure. You can download it from here , at a very affordable price of USD 0.00 (no refunds). The IVM or Integrated Virtualization Manager, is a browser interface to the VIO server on smaller systems, and it has HMC-like functionality, such as Dynamic LPAR, the ability to configure LPARs, stop and start them and so on. The HMC (Hardware Management Console, as you know) is able to manage several... [More]

Tags:  integrated_virtualization... sea management ethernet lpar virtual ivm id outage shared rob_mcnelly hmc v7.3.5.0 dlpar power server aix adapter ibm hardware_management_conso... migration