My question is: our EV database is very large and probably Start-EVDatabaseUpgrade cmdlet will not work correctly. Why? Use EVVaultStoreDB
Select count(*) from JournalArchive where BackupComplete = '0'
Select count(*) from JournalArchive where IndexCommited = '0' return large figures. What will happen with Start-EVDatabaseUpgrade cmdlet execution in this case. It will fail or will work? Backup directly from EV is impossible (Backup mode) - Company works 24/7. If fails – how to resolve it?
The BackupComplete numbers would be from not going in and out of backup mode for EV, whether using archive bit or trigger file. This is essential to allowing the items to be marked secured so they can eventually be removed from the tables. If storage is using replication then that needs to be validated it is working properly. A few million items would be fine in the table. However, numbers greater than 8-10 million would cause longer upgrade times.
For the IndexCommited numbers would need to find out what items are not being indexed. It could be a stored procedure that needs to be updated to allow for indexing to perform more efficiently. There are improvements in the 12.5.3 version in this area as well.
There is an option to truncate the tables and allow the upgrade to process more quickly. This is valid if there are good backups of the storage data and DB's. Indexing can still occur and update items if they are not in the JournalArchive table. This would require a Support case to be opened so that the environment can be checked
Besides the comment from Plaudone, you also might want to consider to start using a new Journal Archive. That way you make sure that the first journal archive is not becoming unmanageable. As for "company works 24/7", I am sure you can set/clear backup mode during quiet time. Even if it is busy 24 hours you NEED to perform that set/clear as Plaudone indicates.
This can be with or without actual backup. Let's assume you cannot backup your data.
Set backup mode. Clear archiving atrribute from files. Clear backup mode. If that is not an option (clearing attribute that is), use the triggerfile.
Set backup mode. create triggerfile (check name in manual), clear backup mode.
Either option will allow EV to perform actions on data it considers safe, and will assist in keeping those tables also 'lean'.
Been there, MM, but nothing is impossible. There are ways this could be done. As a consultant, I'm frequently challenged with situations like this.
If you want to share the counts, I can share some experience on how long it might take to resolve so you can move forward with the upgrade.