Tip of the Day: Oracle LogSync Policy Settings

  • 2
  • Announcement
  • Updated 3 years ago
LogSync settings are accessible only during the Add dSource process, and on the back of the dSource card.

  • Enabled - LogSync adds log files from the source database to the dSource, enabling the ability to provision a VDB from a specific point in time or, a database change number (SCN in the case of Oracle databases, LSN for SQL Server databases). LogSync must be enabled for this provisioning functionality to work.You can enable LogSync for both Oracle and SQL Server dSources. For Oracle dSources, LogSync is disabled  if the source database is detected to be mounted but not open.
  • Archive OnlyArchive and Online Redo - these settings determine whether LogSync fetches logs from archive storage in the source database file system, or both the file system and online redo logs. Setting Archive Only permits the use of LogSync with raw devices or Oracle Automatic Storage Management devices. If LogSync detects that the online logs reside on a raw device or ASM storage during the dSource creation process, and is in Archive and Online Redo mode, it will automatically enter into Archive Only mode. These settings apply to Oracle databases only.
Please Note: LogSync must be enabled for Oracle physical standby databases in Level Backup mode and using Real Time Apply mod
Photo of Jaclyn Schoof

Jaclyn Schoof, Community Manager

  • 5,092 Points 5k badge 2x thumb

Posted 4 years ago

  • 2
Photo of Gianpiero Piccolo

Gianpiero Piccolo

  • 2,336 Points 2k badge 2x thumb
Hi Jaclyn, Hi all,

I'm Gianpiero from Italy. I used the LogSync after reading this interesting post. After i used it, I have two questions I'd like to submit to you and to other mebmers of this community:

For an Oracle dSource, I received an error on the Delphix Engine Demo 4.1.4.0: "Title: Cannot read archived redo logs due to insufficient privileges". Effectively, the DBA had deleted all the contents of the archive directory and so the error is legitimate. But why does Delphix suggest "User Action: .... Alternatively set LogSync to ARCHIVE ONLY mode."? The problem was not of because the online redo logs was missing, but just the archive logs was missing. So I think that if the archive logs are missing I have to switch off the LogSync and it is not enough turn it to ARCHIVE ONLY mode, isn't it?

How much long is the sampling time by which the engine copies the archive log files from the source? Every 5 minutes, every one minute? Because the DBA has scheduled a process that backs up the archive logs on an external storage and then deletes them (for disk space management). Is it sufficient that it deletes all archive log files but the last recent one from the directory of the source oracle database?

Thank you in advance for possible answers.

Gianpiero Piccolo
Photo of Jaclyn Schoof

Jaclyn Schoof, Community Manager

  • 5,092 Points 5k badge 2x thumb
Landshark question

Please reference the new conversation here: Logsync and Landshark
Photo of Gianpiero Piccolo

Gianpiero Piccolo

  • 2,336 Points 2k badge 2x thumb
Thank you