vimal82
1 Nickel

Target size lesser then soucre after SYNIQ replication

Jump to solution


Hi there,

I had recently performed some SYNCIQ replication task. What I released is, after the policy completion (full initial sync) the size of the source is more then the target. For example, the source directory size is 1950GB how ever the target is only 1500GB. The reported SYNCIQ transferred data is only 1300GB. Why such behavior? 

Tags (2)
0 Kudos
1 Solution

Accepted Solutions
Peter_Sero
3 Zinc

Re: Target size lesser then soucre after SYNIQ replication

Jump to solution

The net amount of data (as transferred) is 1300 GB, the other figures include

protection overhead according to the cluster sizes and protection levels.

(With chughh's du command you should see 1300 GB on both sides.)

The mathematically sharp ratios make it tempting to predict the cluster sizes

1950 GB / 1300 GB = 1.5000  = 3/2  typical overhead ratio (for large files) in a 3 nodes cluster with +2:1 protection

                                                            (or 6 nodes cluster with +2 protection, or 9 nodes with +3).

1500 GB / 1300 GB = 1.1538 = 15/13 (sharp)  overhead in a 15 nodes cluster with +2 protection (or 30 nodes with +4).

Does this make sense to you?

-- Peter

3 Replies
Highlighted
chughh
2 Iron

Re: Target size lesser then soucre after SYNIQ replication

Jump to solution

Please check  du -Ash <path used for synciq> on source and target cluster and compare is  data size is same.

Peter_Sero
3 Zinc

Re: Target size lesser then soucre after SYNIQ replication

Jump to solution

The net amount of data (as transferred) is 1300 GB, the other figures include

protection overhead according to the cluster sizes and protection levels.

(With chughh's du command you should see 1300 GB on both sides.)

The mathematically sharp ratios make it tempting to predict the cluster sizes

1950 GB / 1300 GB = 1.5000  = 3/2  typical overhead ratio (for large files) in a 3 nodes cluster with +2:1 protection

                                                            (or 6 nodes cluster with +2 protection, or 9 nodes with +3).

1500 GB / 1300 GB = 1.1538 = 15/13 (sharp)  overhead in a 15 nodes cluster with +2 protection (or 30 nodes with +4).

Does this make sense to you?

-- Peter

vimal82
1 Nickel

Re: Target size lesser then soucre after SYNIQ replication

Jump to solution

Hi Peter_Sero,

Your explanation makes lots of sense. Thanks a bunch.

0 Kudos