When You administrate SAP HANA, You often wonder about questions:
1. How can I reduce size datavolume?
Probably You deleted old: logs, traces and backups. You also RECLAIM DATAVOLUME. What else??
2. If You look at screens below, You see that:
- One of them show that one datavolume use 96% of total size.
- You wonder what’s happen if the total size will be have 100%?
- Maybe You think HANA automatically will be use other datavolume (number 00002 or 00004)??
Answers to the above questions
And in particular to perform reclaim of datavolume the recommendation is follow the steps documented on KBA:
2400005 – FAQ: SAP HANA Persistence – look to the point: 7. How can the persistence be defragmented?
As You can see these recommendation are what you alreday do in your HANA System, but one additional recommendation that SAP usually recommend customers to perform is cleanup the technical tables on HANA System once this helps reduce the space from both memory and disk.
For that please proceed as documented on KBA below:
2388483 – How-To: Data Management for Technical Tables
The HANA services which has persistence layer are documented on KBA:
2400005 – FAQ: SAP HANA Persistence, look to the point: 5. Which SAP HANA services have a persistence?
Meaning that each one of these services has their own datavolume and they cannot have their data/log volume distributed across each other.
For example from the screenshots above the datavolumes 00002 and 00004 belongs to different HANA services. The 00002 belongs to xsengine service while the 00004 belongs to dpserver service.
But the HANA datavolume can grow on demand as long there is space available on disk as documented on KBA:
2910857 – Increase Data Volume free space
Data volumes grow on demand, as long as Your data volumes are stored in disks with enough space so they can grow. There is no need and there are no supported means to manually increase the data volume size. Although “Used/Total Size (%)” show 96% however at the top of Screen 1 You can see column: “Total Disk Size MB” and “Used Disk Size MB” where is information that the disk can grow to about 9.3 TB…