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anataraju / zumastor

Automatically exported from code.google.com/p/zumastor
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replication bloody slow with compression #102

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago 
What steps will reproduce the problem?
1. Create empty volume
2. start replication
3. watch max speed of ~2mpbs

This is on 2 HP workstations with 4 500gb disks on addin PCI sata 
controllers. Both machines on local gigE.

Original issue reported on code.google.com by williama...@gmail.com on 8 Apr 2008 at 12:13

GoogleCodeExporter commented 8 years ago 
1) What is the speed with no compression?

2) What does top show for cpu usage?

Original comment by Daniel.R...@gmail.com on 8 Apr 2008 at 8:37

GoogleCodeExporter commented 8 years ago 
CPU is somewhere between
20418 root      16   0  8096 5864  760 R 41.9  0.2   0:21.34 ddsnap_transmit    

and
20418 root      17   0  7960 5728  760 S 68.8  0.2   0:49.81 ddsnap_transmit    

with compression. Traffic around 2mbps.

Without compression (no -g 6 in ddsnap transmit)
21319 root      16   0  7956 5752  788 R 22.0  0.2   0:13.06 ddsnap_transmit    

and
21319 root      16   0  7956 5752  788 S 16.0  0.2   0:16.77 ddsnap_transmit    

and traffic around 50Mbps. This is mostly data from /dev/urandom.

Original comment by williama...@gmail.com on 8 Apr 2008 at 5:01

GoogleCodeExporter commented 8 years ago

Original comment by williama...@gmail.com on 15 Apr 2008 at 8:09

GoogleCodeExporter commented 8 years ago 
This may be a disk configuration thing, defering to release 10.

Original comment by williama...@gmail.com on 16 Apr 2008 at 6:37