1. © 2011 IBM Corporation Collecting IBM i performance data for sizing with Disk Magic Jana Jamsek ATS Europe

2. © 2011 IBM Corporation IBM Storage Systems Typical IBM i workloads  Day timeframe – On-line transactions – Transaction response time is important  Night timeframe –Batch job Transactions Copying of libraries Save to tape – Duration of batch job is important  Depending on the customer’s preference size for Daily workload, Batch job, or both

3. © 2011 IBM Corporation IBM Storage Systems Collection periods  Depending on the customer’s preference –Daily time –Batch job time –24 hours  Recommended to collect during 3 consecutive days  plus Recommenced to collect during hevay End-of-month job

4. © 2011 IBM Corporation IBM Storage Systems Needed data for sizing and modelling  Performance Tools (Collection Services) data – 5770-PT1  Needed reports for sizing external storage –System report / Disk utilization –Resource report / Disk utilization –Component report / Disk activity –Note: System report / Storage Pool utilization is no more needed for Disk Magic

5. © 2011 IBM Corporation IBM Storage Systems Use 5 minutes intervals

6. © 2011 IBM Corporation IBM Storage Systems After data are collected print the reports

7. © 2011 IBM Corporation IBM Storage Systems Transfer to PC to.txt file with Operations Navigator

8. © 2011 IBM Corporation IBM Storage Systems Determine the peaks  First, insert reports to Disk Magic just to obtain the data in Excell form to observe peaks

9. © 2011 IBM Corporation IBM Storage Systems Determine the peaks - continue  Graphs from Disk Magic spreadsheet  Reports from 7 consecutive days 1. Oct candidate for peak

10. © 2011 IBM Corporation IBM Storage Systems Determine the peaks - continue  Graphs from Disk Magic spreadsheet  Read write ratio is important to determine the peak, because of RAID penalty on write operations Peak in IO/Sec Peak for disk utilization

11. © 2011 IBM Corporation IBM Storage Systems Determine the peaks - continue Peaks in blksize at low IO rate Big blocksizes during entire period: Usually no need for special sizing for blocksize Consider more resourcse

12. © 2011 IBM Corporation IBM Storage Systems Best practise  Size for the peak for disk utilization  Consider big blocksizes if needed  Use Disk Magic to model –Peak by IO/sec –Peak by MB/sec –Peak by write MB/sec –Average

13. © 2011 IBM Corporation IBM Storage Systems Considerations for multiple LPARs  Inserting reports from all LPARs to Disk Magic provides info about IO rate of the sum and of paritcular LPARs  For info reads, writes, and blocksizes insert reports of each LPAR separately to DM and save spreadsheet

14. © 2011 IBM Corporation IBM Storage Systems Best practise  With multiple LPARs – If LPARs will use dedicated ranks size for the peak in each LPAR –If LPARs will share ranks size for peak of the sum; or size for the peak in each LPAR if they are important –Model the peaks of the sum