Avamar：SQL 差異備份完成，並出現異常“在元數據檔中找不到differential_base_lsn值”

Avamar SQL 附掛程式備份記錄會顯示下列差異備份行。

2018-06-06 11:13:39 avsql Warning <17378>: Private properties of resouce could not be resolved for Name.
2018-06-06 11:13:45 avsql Warning <43543>: Couldn't find the differential_base_lsn value in the metadata file. 
Due to the changes in this plugin version, it is recommended to take a FULL backup for the database '<sql-db-name>'.

出現上述警告是因為當檢測到同一資料庫的不同邏輯名稱時，外掛程式備份將「Differential_base_lsn」值保留為空。若要檢查邏輯名稱，請執行 SQL 查詢：

SELECT d.name AS DatabaseName,
       f.name AS LogicalName,
       f.physical_name AS PhysicalName,
       f.type_desc AS TypeofFile
FROM sys.master_files f
INNER JOIN sys.databases d ON d.database_id = f.database_id;

Here are the results:

DatabaseName	LogicalName	PhysicalName	TypeofFile
master		master	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\master.mdf	ROWS
master		mastlog	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\mastlog.ldf	LOG
tempdb		tempdev	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\tempdb.mdf	ROWS
tempdb		templog	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\templog.ldf	LOG
model		modeldev	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\model.mdf	ROWS
model		modellog	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\modellog.ldf	LOG
msdb		MSDBData	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\MSDBData.mdf	ROWS
msdb		MSDBLog	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\DATA\MSDBLog.ldf	LOG
db_1		DB_1	C:\SQL_AG_2\DB_1.mdf	ROWS
db_1		DB_1_log	C:\SQL_AG_2\DB_1_log.ldf	LOG
db1_2020	DB_1	C:\Recovery\db1_2020_data_0.mdf	ROWS
db1_2020	DB_1_log	C:\Recovery\db1_2020_log_0.ldf	LOG
feb13_restore	DB_1	C:\SQL_AG_2\feb13_restore_data_0.mdf	ROWS
feb13_restore	DB_1_log	C:\SQL_AG_2\feb13_restore_log_0.ldf	LOG
db_1_1		DB_1	C:\Program Files\Microsoft SQL Server\MSSQL13.MSSQLSERVER\MSSQL\file	ROWS

當資料庫存在不同的邏輯名稱時，「Differential_base_lsn」值為空。
上述警告訊息會導致備份完成，但發生例外情況，但備份有效且可完全還原。此問題已通過更改外掛程式代碼以不依賴於資料庫邏輯名稱得到解決。

可以安全地忽略警告。
或者，請聯絡 Avamar 支援以取得已完整解決外觀問題的附掛程式 hotfix。