May 20, 2020 – Alert: Possible Data Integrity Issues with Online Backup of Large Databases
InterSystems has corrected two defects that affect online backup of very large databases. Backups taken via external methods, such as snapshots or direct file copies, are not affected. These defects exist in all released versions of all InterSystems products.
The first defect only affects databases with more than 231 blocks. It results in a degraded database after restoring from an online backup. For example, databases that have a block size of 8 KB (the default) are only affected if they are larger than 16 TB. The correction for this defect is identified as RJF437.
The second defect affects databases that have a block size of 8 KB and that are larger than ~29 TB. With this defect, the online backup fails due to an inaccurate <DATABASE> error; this results in a backup that cannot be restored. The correction for this defect is identified as RJF438. Note that this defect also affects databases that have block sizes smaller than 8 KB.
The corrections for these defects will be included in all future product releases. They are also available by requesting an Ad hoc distribution from the WRC.
If you have any questions regarding this alert, please contact the Worldwide Response Center.