Log Volume is Full

[Former Member]

Hi,

Log Volume is Full and the database doesn't accept any new requests.

I have tried to take backup but it is getting failed.

Please suggest what can be done?

Thanks,

Priya

[deepak_chodha · Accepted solution]

Hi Priya,

Actually you need to make sure few things in live systems:

• Make sure the automatic log backup is enabled.
• You install HANA in log drive which has sufficient space available keeping into consideration future db growth. refer to HANA sizing guide for that.

To resolve your issue, follow below:

1. Open HANA Studio.

2. Open SQL editor for your HANA system.

3. Execute:

alter system reclaim log;

4. Take the backup.

HAPPY HANA

Deepak Chodha.

[Former Member]

Hi Priya,

If the log_mode is set to legacy the logvolume keeps all log segments since the last full backup in the logvolume. If no backups are performed the logvolume can run out of space.

1. Stop the database:

HDB stop

2. Change into the folder mnt00001 of the logvolume (Default: /usr/sap/<SID>/global/hdb/log):

cd /usr/sap/<SID>/global/hdb/log/mnt00001

3. You have to move one of the logvolumes temporarily to another volume where enough space is available. You should free at least 2 GB of space to ensure that the database has enough space to start. To find out the space consumption of each volume execute:

du -sh *

4. Move a volume which consumes at least 2 GB of space (e.g. hdb00003) to a volume with enough free space, e.g. to the data volume (Default: /usr/sap/<SID>/global/hdb/data):

mv hdb00003 /usr/sap/<SID>/global/hdb/data

5. Create a symbolic link to the new folder in the old location:

ln -s /usr/sap/<SID>/global/hdb/data/hdb00003 /usr/sap/<SID>/global/hdb/log/mnt00001/hdb00003

6. Start the database (HDB start) and set the log_mode to 'overwrite' using the following SQL-Statement:

ALTER SYSTEM ALTER CONFIGURATION ('global.ini', 'SYSTEM') SET ('persistence', 'log_mode') = 'overwrite' WITH RECONFIGURE;

7. Restart the database (HDB restart) and use the following SQL-Statement to clean up the logvolume:

ALTER SYSTEM RECLAIM LOG;

8. Set back the log_mode to 'legacy' (you should consider switching to log_mode = normal; see note 1645183 for more information):

ALTER SYSTEM ALTER CONFIGURATION ('global.ini', 'SYSTEM') SET ('persistence', 'log_mode') = 'legacy' WITH RECONFIGURE;

9. Stop the database again and remove the symbolic link:

rm -f /usr/sap/<SID>/global/hdb/log/mnt00001/hdb00003

10. Move the log volume back to its original location:

mv /usr/sap/<SID>/global/hdb/data/hdb00003 /usr/sap/<SID>/global/hdb/log/mnt00001

11. Start the database and perform a backup.

Thanks & Regards,

V Srinivasan

[Former Member]

Caution,

ALTER SYSTEM ALTER CONFIGURATION ('global.ini', 'SYSTEM') SET ('persistence', 'log_mode') = 'legacy' WITH RECONFIGURE;

is not supported in rev 74.

I had one issue with this. Hana server was not starting.

[former_member314792]

I encountered the same issue:  DO NOT set 'legacy' log_mode after 74 (my system was SPS09).  If the HANA system does not start, look for an error message in the nameserver log.  To change the parameter, you'll need to edit the custom/config file since HANA Studio is not available.

Donn

[shashisingh]

Hi,

Please  move some log segment to another file system and create a symbolic link to the original directory. It will allow the HANA to restart.

Take a backup from Studio. 

After that try this command  "ALTER SYSTEM RECLAIM LOG" to get free space in the log area.

Thanks,

Shashi

[saroj_bagai]

Steps documented for log full condition does not work on sps 11.  On startup HANA does not recognize the softlink