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VLS9000 dedup performance

Cmorrall
Frequent Advisor

VLS9000 dedup performance

I've recently started to integrate a single node VLS9000 with 40 TB native capacity. The unit also has dedup licenses installed for the full 40 TB.

Backup software is Data Protector 6.1 on Windows, most clients are also Windows.

The VLS works as such, and reading from the statistics, dedup also works at least nominally. The reported dedup ratio is somewhere in the 15:1 to 21:1 region, which is actually better than what I had hoped for.
However, the actual amount of deduped data is only 3.2 TB, now reduced to 0.22 TB. Now I'm at point where the VLS is completely full and has shut down the fibre, as by design.

I know the dedup process is post backup, but does that mean there is no dedup processing at all if there's any backup running to the VLS, or just that a particular backup job is not processed for dedup until the backup job is completed?
If it's the former, that could very well explain why I'm not seeing that much data processed. This system is running at least some backups almost 24x7.

I've not changed the dedup algorithm from the default, which means I'm using file type dedup. We are not using Oracle RMAN or Exchange. Would it be benefitial to change to backup type dedup, and what would the implications be? I can suspect it would consume more resources, perhaps worsen the situation with not enough time for dedup processing.
1 REPLY
Marino Meloni_1
Honored Contributor

Re: VLS9000 dedup performance

There are a lot of factor you should keep in account during the project of using dedup, tuning is a must, and you should know how it work in order to have it working fine.
I can suggest you to read the Dedup solution guide in order to check all the parameters that may cause your vls to fill up with metadata.
http://h20000.www2.hp.com/bizsupport/TechSupport/DocumentIndex.jsp?contentType=SupportManual〈=en&cc=us&docIndexId=64179&taskId=101&prodTypeId=18964&prodSeriesId=3741183
If all the suggestions where already set correctly, it may be that you used the VLS before to enable the deduplication, and in that case, those data will never been deleted.
In that case, you can contact HP, they will analyse your situation based also on the FW version and probably they will give you some script to identify unused data in the metadata, allowing you to access again the VLS and clear from the backup application unused or lost cartridges