Re: dd performance test differences

2018-11-02 Thread Michael Stone
On Fri, Nov 02, 2018 at 01:03:12PM +, Adam Weremczuk wrote: New test results with suggested parameters below: Slower server W: 1310720 bytes (13 GB, 12 GiB) copied, 97.5106 s, 134 MB/s R: 1310720 bytes (13 GB, 12 GiB) copied, 28.6353 s, 458 MB/s Faster server W: 1310720 bytes (1

Re: dd performance test differences

2018-11-02 Thread Adam Weremczuk
Hi Mike, Thanks for the suggestion. New test results with suggested parameters below: Slower server W: 1310720 bytes (13 GB, 12 GiB) copied, 97.5106 s, 134 MB/s R: 1310720 bytes (13 GB, 12 GiB) copied, 28.6353 s, 458 MB/s Faster server W: 1310720 bytes (13 GB) copied, 83.7368 s, 15

Re: dd performance test differences

2018-11-02 Thread Michael Stone
On Fri, Nov 02, 2018 at 11:58:48AM +, Adam Weremczuk wrote: dd if=/dev/zero of=test.bin bs=512 count=1024 oflag=sync That's a uselessly small block size & count. Try again with something more like bs=128k count=10 Note that your dd test is a write test and your testparm is a read tes

Re: dd performance test differences

2018-11-02 Thread Adam Weremczuk
Forgot to mention both run Debian (7.1 and 9.5) and filesystems are ext4 on both. On 02/11/18 11:58, Adam Weremczuk wrote: Hi all, Can somebody explain this huge difference between 2 (almost) identical servers: ---

dd performance test differences

2018-11-02 Thread Adam Weremczuk
Hi all, Can somebody explain this huge difference between 2 (almost) identical servers: - dd if=/dev/zero of=test.bin bs=512 count=1024 oflag=sync 524288 bytes (524 kB) copied, 0.00133898 s, 392 MB/s vs 524