01-07-2019 12:56 AM - edited 01-07-2019 01:02 AM
It is so strange that the vxbench_rhel6_x86_64 program can run successfully and output the result at last, but the system iostat always shows zero during the running process !
Notes: I have tested this with many RHEL5/6 systems, but the same result! It seems that the vxbench for linux does not "support" the system iostat!
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]# nohup ./vxbench_rhel6_x86_64 -w read -i maxfilesize=5000m,nthreads=1,iosize=512,nrep=600000 /dev/sdh > vxbench_sd.out 2>&1 &
[1] 19805
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]# iostat -d sdh 1 6
Linux 2.6.18-194.el5 (RHNBWZ3) 01/06/2019
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 8.50 8.00 0.50 854103674 53366885
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]# iostat -d sdh 1 6
Linux 2.6.18-194.el5 (RHNBWZ3) 01/06/2019
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 8.50 8.00 0.50 854103674 53366885
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sdh 0.00 0.00 0.00 0 0
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[1]+ Done nohup ./vxbench_rhel6_x86_64 -w read -i maxfilesize=5000m,nthreads=1,iosize=512,nrep=600000 /dev/sdh > vxbench_sd.out 2>&1
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]# tail vxbench_sd.out
total1: 50.348 sec 6101539.15 KB/s cpu: 50.01 sys 0.31 user
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
01-17-2019 03:11 AM
You might be hitting the cache, all the time. hence no real reads from
the disk,
Try doing some writes with sync and then read.
01-22-2019 02:50 AM
Even using with -o sync write, the output of the corresponding iostat still does not take effect!
It seems that vxbench_x86 only supports -o sync for write to bypass the OS cache, but not for read!
So now I wonder whether the vxbench_x86 for linux supports the iostat for the native LVM?
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]# ./vxbench_rhel6_x86_64 -w write -i maxfilesize=5000m,nthreads=1,iosize=512,nrep=600 /install/nbu/ESD_NB_7.0_CLIENTS_FA.tar.orig
total1: 0.115 sec 2672419.79 KB/s cpu: 0.11 sys 0.00 user
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]# ./vxbench_rhel6_x86_64 -w write -o sync -i maxfilesize=5000m,nthreads=1,iosize=512,nrep=600 /install/nbu/ESD_NB_7.0_CLIENTS_FA.tar.orig
total1: 49.584 sec 6195.58 KB/s cpu: 0.38 sys 0.00 user
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
avg-cpu: %user %nice %system %iowait %steal %idle
40.32 0.00 0.09 0.17 0.00 59.42
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
vgroot-lvinstall
0.22 0.00 0.00 81749 14138
avg-cpu: %user %nice %system %iowait %steal %idle
0.12 0.00 6.49 1.00 0.00 92.39
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
vgroot-lvinstall
0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
0.06 0.00 6.25 1.00 0.00 92.69
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
vgroot-lvinstall
131.00 0.00 0.51 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
1.31 0.00 6.31 2.44 0.00 89.94
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
vgroot-lvinstall
128.00 0.00 0.50 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
0.06 0.00 6.30 0.00 0.00 93.63
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
vgroot-lvinstall
0.00 0.00 0.00 0 0
avg-cpu: %user %nice %system %iowait %steal %idle
0.06 0.00 6.24 1.19 0.00 92.51
Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn
vgroot-lvinstall
0.00 0.00 0.00 0 0
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]# ./vxbench_rhel6_x86_64 -w read -o sync -i maxfilesize=5000m,nthreads=1,iosize=512,nrep=600 /install/nbu/ESD_NB_7.0_CLIENTS_FA.tar.orig
total1: 0.076 sec 4015738.77 KB/s cpu: 0.07 sys 0.00 user
[root@RHNBWZ3 tmp]#
[root@RHNBWZ3 tmp]#