hi,
I would like to give you an update about the restore tests. I restored the smallest one,7TB with 4600 files.
It took a lot less time. the high number of files definitely impacts on the timing.
2017-03-28 09:45:45.210 spid58 RestoreDatabase: Finished
2017-03-28 09:45:45.180 Backup RESTORE DATABASE successfully processed 62086684 pages in 3003.526 seconds (161.494 MB/sec).
2017-03-28 09:45:45.180 spid58 Restore: Done with MSDB maintenance
2017-03-28 09:44:14.340 spid58 Writing backup history records
2017-03-28 09:44:07.600 Backup Database changes were restored. Database: db_xxxxxx2, creation date(time): 2011/12/19(12:47:05), first LSN: 11396148:9851828:16, last LSN: 11396148:10901616:1, number of dump devices: 1, device information: (FILE=1, TYPE=DISK: {'X:\xxxxxxx.diff'}). This is an informational message. No user action is required.
2017-03-28 09:44:07.600 spid58 Restore: Writing history records
2017-03-28 09:44:07.350 spid58 Resuming any halted fulltext crawls
2017-03-28 09:44:07.090 Backup Restore is complete on database 'db_xxxxxx2'. The database is now available.
2017-03-28 09:44:07.090 spid58 Restore: Database is restarted
2017-03-28 09:44:06.850 spid58 PostRestoreReplicationFixup for db_xxxxxx2 complete
2017-03-28 09:44:04.660 spid58 PostRestoreReplicationFixup for db_xxxxxx2 starts
2017-03-28 09:44:04.630 spid58 CHECKDB for database 'db_xxxxxx2' finished without errors on 2017-02-18 08:04:33.693 (local time). This is an informational message only; no user action is required.
2017-03-28 09:44:04.200 spid58 PostRestoreContainerFixups: fixups complete
2017-03-28 09:43:50.980 spid58 Recovery completed for database db_xxxxxx2 (database ID 5) in 7 second(s) (analysis 429 ms, redo 1812 ms, undo 4387 ms.) This is an informational message only. No user action is required.
2017-03-28 09:43:50.820 spid58 Recovery is writing a checkpoint in database 'db_xxxxxx2' (5). This is an informational message only. No user action is required.
2017-03-28 09:43:45.490 spid58 Zeroing completed on X:\Data\db_xxxxxx2\db_xxxxxx2_log.ldf
2017-03-28 09:43:45.480 spid58 Zeroing X:\Data\db_xxxxxx2\db_xxxxxx2_log.ldf from page 60514567 to 60515047 (0x736c20e000 to 0x736c5ce000)
2017-03-28 09:43:22.950 spid58 Starting up database 'db_xxxxxx2'.
2017-03-28 09:43:19.540 spid58 Restore: Restarting database for ONLINE
2017-03-28 09:43:19.480 spid58 Restore: Transitioning database to ONLINE
2017-03-28 09:43:19.430 spid58 Restore: Done with fixups
2017-03-28 09:43:18.950 spid58 Rollforward complete on database db_xxxxxx2
2017-03-28 09:43:08.630 spid58 OfflineRollforward: StopLsn/LastLsn(PruId: 0): 0xade434:0xa65870:0x1
2017-03-28 09:42:46.480 spid58 RunOfflineRedo logIter.Init(): LastLsn(PruId: 0): 0xade434:0xa65870:0x1
2017-03-28 09:42:46.480 spid58 RunOfflineRedo logIter.Init(): FirstLsn(PruId: 0): 0xade434:0x9653b4:0x10
2017-03-28 09:42:46.380 spid58 Restore VLF headers completed on database db_xxxxxx2
2017-03-28 09:42:45.020 spid58 Restore VLF headers for 209 headers on database db_xxxxxx2
2017-03-28 09:42:42.240 spid58 Restore-Redo begins on database db_xxxxxx2
2017-03-28 09:42:42.040 spid58 The database 'db_xxxxxx2' is marked RESTORING and is in a state that does not allow recovery to be run.
2017-03-28 09:42:28.130 spid58 Starting up database 'db_xxxxxx2'.
2017-03-28 09:42:25.050 spid58 Restore: Backup set restored
2017-03-28 09:42:24.130 spid58 Restore: Data transfer complete on db_xxxxxx2
2017-03-28 09:42:24.130 spid58 FileHandleCache: 0 files opened. CacheSize: 140
2017-03-28 09:41:45.800 spid58 SetTargetRestoreAge: 0
2017-03-28 09:41:41.050 spid58 Restore: LogZero complete
2017-03-28 09:41:41.040 spid58 Zeroing completed on X:\Data\db_xxxxxx2\db_xxxxxx2_log.ldf
2017-03-28 09:12:06.050 spid58 Restore: Waiting for log zero on db_xxxxxx2
2017-03-28 09:12:06.050 spid58 Completed MSDA in stream 0, thread 6436
2017-03-28 08:52:20.310 spid58 Starting MSDA in stream 0, thread 6436, length 0x764bc00000
2017-03-28 08:52:20.310 spid58 Restore: Transferring data to db_xxxxxx2
2017-03-28 08:52:20.310 spid58 Restore: Restoring backup set
2017-03-28 08:52:20.010 spid58 Restore: Containers are ready
2017-03-28 08:52:19.990 spid58 Zeroing X:\Data\db_xxxxxx2\db_xxxxxx2_log.ldf from page 1 to 91290496 (0x2000 to 0xae1f700000)
2017-03-28 08:51:29.000 spid58 Restore: PreparingContainers
2017-03-28 08:51:24.910 spid58 Restore: BeginRestore (offline) on db_xxxxxx2
2017-03-28 08:51:24.910 spid58 Restore: Planning complete
2017-03-28 08:51:24.910 spid58 Dismounting FullText catalogs
2017-03-28 08:51:12.230 spid58 Restore: Planning begins
2017-03-28 08:51:12.230 spid58 Restore: Backup set is open
2017-03-28 08:51:12.230 spid58 Restore: Configuration section loaded
2017-03-28 08:51:11.850 spid58 SetTargetRestoreAge: 0
2017-03-28 08:51:11.510 spid58 Opening backup set
2017-03-28 08:51:11.460 spid58 X-locking database: db_xxxxxx2
2017-03-28 08:51:11.310 spid58 RestoreDatabase: Database db_xxxxxx2
2017-03-28 08:51:11.310 spid58 DBCC TRACEON 3605, server process ID (SPID) 58. This is an informational message only; no user action is required.
2017-03-28 08:51:11.310 spid58 DBCC TRACEON 3604, server process ID (SPID) 58. This is an informational message only; no user action is required.
2017-03-28 08:51:11.310 spid58 DBCC TRACEON 3014, server process ID (SPID) 58. This is an informational message only; no user action is required.
2017-03-28 08:51:11.310 spid58 DBCC TRACEON 3004, server process ID (SPID) 58. This is an informational message only; no user action is required.
(this is differential restore log only)
this confirms what previously said about number of files,
ty all
bye bye