Things that do not cause low-splash backups

• Connector upgrades
• Graceful system reboots
• Graceful restarts of cbt_server or AAMService assuming that the service isstill running at the time of backup
• Failovers that did not experience the errors that cause unreliable bitmaps.

Causes of unreliable bitmaps

An unreliable bitmap occurs when something interrupts the backup job, includingthe following:

• An unclean shutdown of the host
  • A non-graceful shutdown causes low-splash due to unreliability of bitmaps.This includes pulling power on a physical machine or any other methodof turning off Windows without going through a graceful shutdown, or a bluescreen error. This is true even if one machine in a cluster hits a bluescreen error that triggers failover, since the bitmap from the failed machineis unreliable.
  • If all Windows servers in a cluster that have hosted the database since theprevious backup are not available and running Actifio services. We pullbitmaps from each cluster host which hosted the database since the previousbackup to find changes, and without all bitmaps, we have to run low-splash tomaintain data integrity. Note that if a cluster host that hosted a databasehits a BSOD, the bitmap might be available at backup but still be unreliable,so low-splash.
• A failed kernel module update
• A crash or a restart in the user mode daemon
• A fingerprint error while running a backup. (Backup and DR Service performs a"fingerprint check" on each backup job to check for errors.)
• Error during vaulting, if during OS shutdown the storage disk is full and thesystem cannot write all data into the vault.
• SAP HANA node failover, causing the backup to be redirected to a differentnode.
• Backup running in degraded mode due to inability to load the kernel module.This typically occurs when the OS is an unsupported version.
• If cbt_server or AAMService is stopped during the backup, then bitmaps cannotbe fetched and the backup job runs in low-splash mode.If AAMService is not down for very long, then starting AAMService will resultin bitmaps being available for a normal backup.
  • If cbt_server or AAMService is stopped for long enough that some gigabytes ofevents are queued by the driver, then the bitmaps cannot be recreated andthe backup will be in low-splash mode. How long this takes depends on howmuch disk I/O happens on the database. This typically require days ofAAMService downtime.
• Non-graceful shutdown of the cbt_server or AAMService can causebitmaps to become unreliable for any currently-loaded bitmaps. Bitmaps areloaded if the tracked file has been written to in the last 15 minutes, sogenerally for a busy database this would cause low-splash.
• If a volume containing a tracked file (e.g. a SQL Server .mdf file) isunmounted on the host and then re-mounted, the bitmaps are unreliable sincethere is no way to know what was written to the file while it was unmounted.