[CentOS] Performance issues/difference of two servers running same task (one is quicker)

Jobst Schmalenbach
2019-07-06T00:37:54Z

On Thu, Jul 04, 2019 at 09:39:18AM +0200, Roberto Ragusa (mail at
robertoragusa.it) wrote:
> On 7/4/19 8:43 AM, Jobst Schmalenbach wrote:
> >Clearly the development server is hardware wise way below the specs of
the Dell but
> >software wise they are identical (they get upgraded at the same time).
> As a first step, you have to test subsystems one by one.

Thank you for the tips.
Here are the results (DELL is faster overall):

> time dd 2>/dev/null if=/dev/zero of=/dev/null bs=1 count=1000000

[DIY ~] #>time dd 2>/dev/null if=/dev/zero of=/dev/null bs=1 count=1000000
real    0m1.931s
user    0m1.022s
sys     0m0.896s
[DELL ~] #>time dd 2>/dev/null if=/dev/zero of=/dev/null bs=1
count=1000000
real    0m1.308s
user    0m0.389s
sys     0m0.919s

Dell faster overall

> cd /a/directory/on/the/filesystem/you/want/to/test
> time bash -c "for((i=0;i<1000;i++)); do dd 2>/dev/null
if=/dev/zero of=test bs=1 count=1 conv=fsync;done"
> rm test

[DIY /mnt] #>time bash -c "for((i=0;i<1000;i++)); do dd
2>/dev/null if=/dev/zero of=test bs=1 count=1 conv=fsync;done"
real    1m12.944s
user    0m1.604s
sys     0m2.595s
[DELL /mnt] #>time bash -c "for((i=0;i<1000;i++)); do dd
2>/dev/null if=/dev/zero of=test bs=1 count=1 conv=fsync;done"
real    0m2.270s
user    0m0.509s
sys     0m1.475s

Expected the DIY to be slower here, it's running MDADM RAID1 on Seagete
Spinners compared to LSI RAID1 SSD

The result shows the DELL overall is faster, back to the drawing board after I
followed all the other hints in this thread.


Jobst