Copy only full db backup affect the lsn sequence of log backup not the differential backup

--Take the Full backup without copy_only

BACKUP DATABASE [DBA_Test] TO  DISK = N'F:\Backup\DBA.bak' WITH  init ,STATS = 10, CHECKSUM

--,copy_only

--Initiate the transaction for the T-og backup

use DBA_Test

create table t4

(

id int

)

insert into t4 values (1)

go 100

--Take the T-log backup

BACKUP LOG [DBA_Test] TO  DISK = N'F:\Backup\dba1.trn' WITH NOFORMAT, INIT,  NAME = N'DBA_Test-Transaction Log  Backup',

SKIP, NOREWIND, NOUNLOAD,  STATS = 10, CHECKSUM

--Before we perform the copy_only full backup , let's initiate another 100 records so we can check last T-log backup able to recover this contents and

--also it confirms copy_only full backup don't affect the log sequence

insert into t4 values (1)

go 100

--Take the full backup copy_only

BACKUP DATABASE [DBA_Test] TO  DISK = N'F:\Backup\DBA1.bak' with STATS = 10, CHECKSUM,copy_only

--initiate the transaction again

insert into t4 values (1)

go 100

--Take another log backup

BACKUP LOG [DBA_Test] TO  DISK = N'F:\Backup\dba2.trn' WITH NOFORMAT,  NAME = N'DBA_Test-Transaction Log  Backup',

SKIP, NOREWIND, NOUNLOAD,  STATS = 10, CHECKSUM

---Now recover the database

--i.e -1. Initial Full backup

     --2. T-log 1 (expected to recover 100 records)

        --3. T-log 2 (expected to recover 200 records without affecting lsn sequence)

--see the attached recovery option

--Conclusion ... Copy only full db backup does affect the lsn sequence when it comes to regular backups but it won't affect differential backup.