Intel AS/400 RISC Server, 170 Servers, 7xx Servers Save and Restore Rates, Large File Concurrent

15.9.2 Large File Concurrent

For the concurrent testing 16 libraries were built, each containing a single 320 GB file with 80 4 GB members. The file size was chosen to sustain a flow across the HSL, system bus, processors, memory and tapes drives for about an hour. We were not interested in peak performance here but sustained performance. Measurements were done to show scaling from 1 to 16 tape drives, knowing that near the top number of tape drives that the system would become the limiting factor and not the tape drives. This could be used by customers to give them an estimate at what might be a reasonable number of tape drives for their situation.

Table 15.9.2.1 iV5R2 16 - 3580.002 Fiber Channel Tape Device Measurements (Concurrent)

(Save = S, & Restore = R)

# 3580.002		1	2	3	4	8	12	13	14	15	16
Tape drives
320 GB	S	365	730	1.09	1.45	2.88	4.15	4.63	4.90	5.14	5.21
DB file with		GB/HR	GB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR
80 4 GB
	R	340	680	1.01	1.33	2.56	3.73	4.02	4.28	4.54	4.68
members		GB/HR	GB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR	TB/HR

In the table above, you will notice that the 16th drive starts to loose value. Even though there is gain we feel we are starting to see the system saturation points start to factor in. Unfortunately, we didn’t have anymore drives to add in but believe that the total data throughput would be relatively equal, even if any more drives were added.

Save and Restore Rates

Large File Concurrent Runs

	6
	5							5.2 TB/HR
TB/HR	4								Save
	3								Restore
	2
	1
	0
	1	3	5	7	9	11	13		15
	2		4	6	8	10	12	14	16

# 3580 model 002 Tape Drives

IBM i 6.1 Performance Capabilities Reference - January/April 2008
© Copyright IBM Corp. 2008	Chapter 15. Save/Restore Performance	250