On 04/ 9/10 01:40 PM, Phil Stracchino wrote: > On 04/09/10 02:35, Henrik Johansen wrote: >> I have spend some time profiling the bacula-sd under production load on >> Solaris. Besides checking for signs of lock contention and memory / CPU >> usage issues I also tracked the I/O statistics for each file descriptor >> opened within the bacula-sd process while running. >> >> According to my notes there was a noticeable change in throughput when >> testing 100 concurrent jobs against 100 separate devices (100 separate >> volumes) compared against writing the same jobs against 20 concurrent >> volumes. >> >> I/O throughput increased with more concurrency. > > That is an extremely interesting, and somewhat counter-intuitive, result.
The SD uses asynchronous writes - concurrency seems to make data arrives faster in the ARC which in turn results in faster writes seen from within the application - at least that's what I am speculating :) >> There also was a noticeable increase in CPU time between those tests >> (more concurrency == more CPU time spend by the bacua-sd process) but >> nothing that worried me (but may need further investigation to fully >> understand). >> >> The above is specific to our setup so YMMV on other platforms and hardware. > > What precisely is the hardware platform for this test? Dell 2900 (Gen III) with 32 GB RAM and 2 x 3 Ghz Xeon Quad Core CPU's running OpenSolaris (b134), 4 x PERC 6/E controllers, 7 MD1000 JBOD's with dual I/O modules, 105 x 750 GB nearline SAS disks and 1 dual port Intel 10 Gbit NIC. The zpool is comprised of 14 narrow (7 disk wide) raidz2 vdevs. This configuration should allow a fair balance between bandwidth and IOPS while retaining enough free space to be economically feasible for disk backup. > -- Med venlig hilsen / Best Regards Henrik Johansen [email protected] Tlf. 75 53 35 00 ScanNet Group A/S ScanNet ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Bacula-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/bacula-devel
