1. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure Upon completion of this module, you should be able to: Describe VNX SnapSure theory and operations Configure SnapSure Plan and manage SnapSure VNX SnapSure1

2. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure This lesson covers the following topics: Purpose of SnapSure Key components of SnapSure SnapSure theory of operations VNX SnapSure storage usage Checkpoint scheduling Lesson 1: VNX SnapSure Theory of Operations VNX SnapSure2

3. Copyright © 2014 EMC Corporation. All Rights Reserved. SnapSure Overview VNX SnapSure3 Provides a point-in-time view of a file system known as a “checkpoint” Used mostly in backups and file system restores Purpose of SnapSure Live data viewed directly from production file system Point-in-time, read-only view from a checkpoint of the production file system (PFS) Two views of a file system

4. Copyright © 2014 EMC Corporation. All Rights Reserved. User’s Views of Data VNX SnapSure4 biz_proposal Production File System Checkpoints Production Wednesday View Tuesday View Monday View Read-only Live Read-only Read-only biz_proposal

5. Copyright © 2014 EMC Corporation. All Rights Reserved. Key Components Production File System (PFS) Checkpoint  Logical point-in-time view of data  Also known as a “snapshot” SavVol  Stores original data blocks to preserve the point in time view Bitmap  Identifies changed data blocks in the PFS Blockmap  Records the location of data blocks in the SavVol VNX SnapSure5

6. Copyright © 2014 EMC Corporation. All Rights Reserved. Theory of Operation: Part 1 of 7 VNX SnapSure6 Creating a checkpoint SavVol 0 Bitmap 00000 Blockmap1 PFS SavVol PFS ABCDEF Ckpt 1 Data Storage Area

7. Copyright © 2014 EMC Corporation. All Rights Reserved. Theory of Operation: Part 2 of 7 VNX SnapSure7 SavVol 0 Bitmap 00000 Blockmap1 PFS SavVol PFS ABCDEF Ckpt 1 Data Storage Area H K 1. Write request is made 2. Check the Bitmap value 1 2

8. Copyright © 2014 EMC Corporation. All Rights Reserved. Theory of Operation: Part 3 of 7 VNX SnapSure8 Writing to the PFS 1. Issue write hold 2. Copy original data into SavVol blocks 3. Map PFS block to SavVol block 4. Update bitmap value to 1 5. Release write hold SavVol 0 Bitmap 01001 Blockmap1 B 21 E 25 2 3 4 PFS SavVol PFS ABCDEF Ckpt 1 H K Hold 1 5

9. Copyright © 2014 EMC Corporation. All Rights Reserved. Theory of Operation: Part 4 of 7 VNX SnapSure9 Creating a second checkpoint SavVol 0 Bitmap 00000 Blockmap1 B 21 E 25 PFS SavVol Blockmap2 PFS SavVol PFS AHCDKF Ckpt 1Ckpt 2 Bitmap is reset to zero values A new blockmap is created for Ckpt2

10. Copyright © 2014 EMC Corporation. All Rights Reserved. Theory of Operation: Part 5 of 7 VNX SnapSure10 Writing to the PFS with Ckpt2 SavVol 1 Bitmap 11000 Blockmap1 B 21 E 25 PFS SavVol Blockmap2 PFS SavVol 1 2 6 5 4 3 AH F PFS AHCDKF Ckpt 1Ckpt 2 JLS Hold New 1 2 3 4 5 1. Issue write hold 2. Copy data into SavVol 3. Update Ckpt2’s blockmap 4. Update bitmap values 5. Release write hold

11. Copyright © 2014 EMC Corporation. All Rights Reserved. Theory of Operation: Part 6 of 7 VNX SnapSure11 Reading from active checkpoint SavVol 1 Bitmap 11000 Blockmap1 B 21 E 25 PFS SavVol Blockmap2 PFS SavVol 1 2 6 5 4 3 AH F 3 3 2 1 PFS JLCDKS Ckpt 1Ckpt 2 AHKF CD 1. Read Bitmap values 2. “0” - Retrieve data from PFS 3. “1” - Retrieve data from SavVol Active Old

12. Copyright © 2014 EMC Corporation. All Rights Reserved. Theory of Operation: Part 7 of 7 VNX SnapSure12 Reading from old checkpoint SavVol 1 Bitmap 11000 Blockmap1 B 21 E 25 PFS SavVol Blockmap2 PFS SavVol 1 2 6 5 4 3 AH F 2 3 1 PFS JLCDKS Ckpt 1Ckpt 2 ABEF CD Active Old 1. Read older checkpoint’s blockmap 2. Aggregate oldest values 3. Verify active checkpoint’s blockmap for location

13. Copyright © 2014 EMC Corporation. All Rights Reserved. SavVol Storage Considerations All checkpoints of a PFS share the same SavVol VNX SnapSure13 Automatically-created SavVols Manually-created SavVols Uses the same storage pool as the PFS unless otherwise specified If PFS ≥ 20GB then SavVol = 20GB If PFS 64MB then SavVol = PFS size If PFS ≤ 64MB then SavVol = 64MB A manually-created metavolume is selected during checkpoint creation Best practice is to create a SavVol that is 10% of PFS size Offers more control on which disks to place the SavVol

14. Copyright © 2014 EMC Corporation. All Rights Reserved. SavVol Automatic Extension Automatic extension is triggered by High Water Mark (HWM)  HWM is 90% by default  Will not exceed 20% of total VNX space by default SavVol automatic extensions increase in 20 GB increments, or by 10% if SavVol was manually created To disable automatic SavVol extension, set HWM to 0%  First, SnapSure uses remaining space in SavVol  Then, SnapSure will overwrite the oldest checkpoint Refresh checkpoints to recycle SavVol storage VNX SnapSure14

15. Copyright © 2014 EMC Corporation. All Rights Reserved. Checkpoint Scheduling Overview VNX SnapSure15 Automates checkpoint creation and refresh Configured via Unisphere or Control Station CLI Schedules may be on an hourly, daily, weekly, or monthly basis More than one schedule per PFS is allowed Proper VNX for File privileges is required Read-only: list and view schedules Modify: change, pause, and resume schedules Full: create and delete schedules

16. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure During this lesson the following topics were covered: Purpose of SnapSure Key components of SnapSure SnapSure theory of operations VNX SnapSure storage usage Checkpoint scheduling Lesson 1: Summary VNX SnapSure16

17. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure This lesson covers the following topics: Checkpoint creation and verification Displaying existing checkpoints Accessing the checkpoint Configuring checkpoint scheduling Lesson 2: Configuring SnapSure VNX SnapSure17

18. Copyright © 2014 EMC Corporation. All Rights Reserved. Creating a Checkpoint Data Protection > Snapshots > File System Checkpoints VNX SnapSure18

19. Copyright © 2014 EMC Corporation. All Rights Reserved. Displaying Checkpoints VNX SnapSure19

20. Copyright © 2014 EMC Corporation. All Rights Reserved. Accessing Checkpoints via CVFS SnapSure navigation feature for end users to view and restore checkpoint data without any Administrator involvement  CIFS or NFS read-only access “.ckpt” is the name of the hidden directory containing checkpoint data  Name may be modified via param file Naming convention of individual checkpoints  yyyy_mm_dd_hh_mm_ss_  CVFS names can be changed when remounting the checkpoint VNX SnapSure20

21. Copyright © 2014 EMC Corporation. All Rights Reserved. [root@linux08b student8]# ls -la total 10323052 drwxr-xr-x. 5 root root 1024 Sep 18 22:34. dr-xr-xr-x. 27 root root 4096 Sep 16 01:43.. dr-xr-xr-x. 2 root bin 1024 Sep 18 22:25.etc -rw-r--r--. 1 root root 2857369600 Sep 16 01:48 filename -rw-r--r--. 1 root root 1652555776 Sep 16 01:48 filename2 -rw-r--r--. 1 root root 6055657472 Sep 16 01:50 filename3 drwxr-xr-x. 2 root root 8192 Sep 11 14:13 lost+found [root@linux08b student8]# [root@linux08b student8]# ls -la.ckpt total 33 dr-xr-xr-x. 2 root root 512 Sep 18 22:47. drwxr-xr-x. 5 root root 1024 Sep 18 22:34.. drwxr-xr-x. 5 root root 1024 Sep 16 01:48 2013_09_18_21.46.01_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:50 2013_09_18_21.51.29_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:56 2013_09_18_21.57.24_GMT [root@linux08b student8]# [root@linux08b student8]# ls -la total 10323052 drwxr-xr-x. 5 root root 1024 Sep 18 22:34. dr-xr-xr-x. 27 root root 4096 Sep 16 01:43.. dr-xr-xr-x. 2 root bin 1024 Sep 18 22:25.etc -rw-r--r--. 1 root root 2857369600 Sep 16 01:48 filename -rw-r--r--. 1 root root 1652555776 Sep 16 01:48 filename2 -rw-r--r--. 1 root root 6055657472 Sep 16 01:50 filename3 drwxr-xr-x. 2 root root 8192 Sep 11 14:13 lost+found [root@linux08b student8]# [root@linux08b student8]# ls -la.ckpt total 33 dr-xr-xr-x. 2 root root 512 Sep 18 22:47. drwxr-xr-x. 5 root root 1024 Sep 18 22:34.. drwxr-xr-x. 5 root root 1024 Sep 16 01:48 2013_09_18_21.46.01_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:50 2013_09_18_21.51.29_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:56 2013_09_18_21.57.24_GMT [root@linux08b student8]# NFS Client Checkpoint Access VNX SnapSure21.ckpt directory has to be explicitly specified Checkpoints appear as directories

22. Copyright © 2014 EMC Corporation. All Rights Reserved. NFS Client Checkpoint Access (continued) VNX SnapSure22 [root@linux08b student8]# cd.ckpt [root@linux08b.ckpt]# ls -l total 24 drwxr-xr-x. 5 root root 1024 Sep 16 01:48 2013_09_18_21.46.01_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:50 2013_09_18_21.51.29_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:56 2013_09_18_21.57.24_GMT [root@linux08b.ckpt]# [root@linux08b.ckpt]# cd 2013_09_18_21.46.01_GMT [root@linux08b 2013_09_18_21.46.01_GMT]# [root@linux08b 2013_09_18_21.46.01_GMT]# ls -la total 10323049 drwxr-xr-x. 5 root root 1024 Sep 16 01:48. dr-xr-xr-x. 2 root root 512 Sep 18 22:42.. dr-xr-xr-x. 2 root bin 1024 Sep 18 21:25.etc -rw-r--r--. 1 root root 2857369600 Sep 16 01:48 filename -rw-r--r--. 1 root root 6055657472 Sep 16 01:50 filenames -rw-r--r--. 1 root root 1652555776 Sep 16 01:48 filname drwxr-xr-x. 2 root root 8192 Sep 11 14:13 lost+found [root@linux08b 2013_09_18_21.46.01_GMT]# [root@linux08b student8]# cd.ckpt [root@linux08b.ckpt]# ls -l total 24 drwxr-xr-x. 5 root root 1024 Sep 16 01:48 2013_09_18_21.46.01_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:50 2013_09_18_21.51.29_GMT drwxr-xr-x. 5 root root 1024 Sep 18 21:56 2013_09_18_21.57.24_GMT [root@linux08b.ckpt]# [root@linux08b.ckpt]# cd 2013_09_18_21.46.01_GMT [root@linux08b 2013_09_18_21.46.01_GMT]# [root@linux08b 2013_09_18_21.46.01_GMT]# ls -la total 10323049 drwxr-xr-x. 5 root root 1024 Sep 16 01:48. dr-xr-xr-x. 2 root root 512 Sep 18 22:42.. dr-xr-xr-x. 2 root bin 1024 Sep 18 21:25.etc -rw-r--r--. 1 root root 2857369600 Sep 16 01:48 filename -rw-r--r--. 1 root root 6055657472 Sep 16 01:50 filenames -rw-r--r--. 1 root root 1652555776 Sep 16 01:48 filname drwxr-xr-x. 2 root root 8192 Sep 11 14:13 lost+found [root@linux08b 2013_09_18_21.46.01_GMT]#

23. Copyright © 2014 EMC Corporation. All Rights Reserved. CIFS Client Checkpoint Access In the address field of Windows Explorer, enter \.ckpt to list the checkpoints associated with the file system share VNX SnapSure23 Manually type the path to.ckpt

24. Copyright © 2014 EMC Corporation. All Rights Reserved. Accessing Checkpoints via Shadow Copy Client CIFS clients can also access checkpoint data via Shadow Copy Client Native with Windows 2003 and later OS versions  Download available for Windows 2000 and XP Select “Previous Versions” tab on the file system share Properties window VNX SnapSure24

25. Copyright © 2014 EMC Corporation. All Rights Reserved. Displaying Checkpoint Schedules Data Protection > Snapshots > File System Checkpoints > Schedules Tab VNX SnapSure25 Schedule states  Active  Pending  Paused  Complete

26. Copyright © 2014 EMC Corporation. All Rights Reserved. Creating a Checkpoint Schedule VNX SnapSure26 Use relative prefix to make script writing easier Checkpoint names may be assigned

27. Copyright © 2014 EMC Corporation. All Rights Reserved. SnapSure Considerations VNX SnapSure27 Checkpoints depend on PFS and are not originally intended for : Disaster recovery Mirror High-availability SnapSure supports 96 read-only checkpoints + 16 writeable Includes existing checkpoints, checkpoints in a schedule Avoid creating or scheduling checkpoints during these time periods 1 to 5 minutes past the hour 15 minutes of each other in the same schedule or between schedules on the same PFS

28. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure During this lesson the following topics were covered: Checkpoint creation and verification Displaying existing checkpoints Accessing the checkpoint Configuring checkpoint scheduling Lesson 2: Summary VNX SnapSure28

29. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure This lesson covers the following topics: Planning checkpoint schedules Performance considerations Lesson 3: Planning SnapSure 29VNX SnapSure

30. Copyright © 2014 EMC Corporation. All Rights Reserved. Schedule Planning 30 Do not schedule checkpoint operations at the same time as VNX for File database backup Do not schedule checkpoints to occur/refresh at the same time Missed tasks will be retried Important considerations when planning a checkpoint schedule VNX SnapSure

31. Copyright © 2014 EMC Corporation. All Rights Reserved. PFS Performance Implications 31 Only reads allowed on the PFS, all write activity will be suspended Checkpoint Creation Only reads allowed on the PFS, all write activity will be suspended Checkpoint Deletion All PFS I/O activity is suspended during restore initialization Checkpoint Restore Write I/O is suspended until original data is copied to the SavVol Copy On First Write VNX SnapSure

32. Copyright © 2014 EMC Corporation. All Rights Reserved. Client Performance Implications Refreshing a checkpoint affects user or application access  During a refresh, the checkpoint is deleted and a new one is created with the same name  Checkpoint being refreshed will have all read I/O activity suspended If a checkpoint becomes inactive or corrupted, read/write activity on the PFS will continue  The PFS does not depend on the checkpoint, but the checkpoint depends on the PFS 32VNX SnapSure

33. Copyright © 2014 EMC Corporation. All Rights Reserved. SavVol Performance and Disk Type SavVol writes are sequential, while reads are random 33 SASNL-SAS Better suited when checkpoints are accessed by heavy read workloads Sharing data between users Data mining Testing When multiple SavVols will be sharing the same disks Very good sequential I/O performance Use if checkpoints will be read infrequently May be used generally if cost is more important than checkpoint performance VNX SnapSure

34. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure During this lesson the following topics were covered: Planning checkpoint schedules Performance considerations Lesson 3: Summary 34VNX SnapSure

35. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure This lesson covers the following topics: Storage management for checkpoints Modifying SnapSure schedules Memory management for checkpoints Lesson 4: Managing Checkpoints 35VNX SnapSure

36. Copyright © 2014 EMC Corporation. All Rights Reserved. Checkpoint Storage Consumption 36 Checkpoint Properties page VNX SnapSure

37. Copyright © 2014 EMC Corporation. All Rights Reserved. Listing Checkpoints via CLI 37 [nasadmin@VNXB ~]$ fs_ckpt fs16 -list id ckpt_name creation_time inuse fullmark total_ ckpt_ savvol_ usage_on used savvol 16 Monday 09/18/2013-05:33:52-EDT y 90% 8% 1% 17 Tuesday 09/18/2013-05:39:20-EDT y 90% 8% 1% 18 Wednesday 09/18/2013-05:45:15-EDT y 90% 8% 1% 20 ProdData1 09/24/2013-12:10:00-EDT y 90% 8% 1% 21 ProdData2 09/24/2013-13:10:00-EDT y 90% 8% 1% 22 ProdData3 09/24/2013-14:10:00-EDT y 90% 8% 1% Info 26306752329: The value of ckpt_usage_on_savvol for read-only checkpoints may not be consistent with the total_savvol_used. [nasadmin@VNXB ~]$ [nasadmin@VNXB ~]$ fs_ckpt fs16 -list id ckpt_name creation_time inuse fullmark total_ ckpt_ savvol_ usage_on used savvol 16 Monday 09/18/2013-05:33:52-EDT y 90% 8% 1% 17 Tuesday 09/18/2013-05:39:20-EDT y 90% 8% 1% 18 Wednesday 09/18/2013-05:45:15-EDT y 90% 8% 1% 20 ProdData1 09/24/2013-12:10:00-EDT y 90% 8% 1% 21 ProdData2 09/24/2013-13:10:00-EDT y 90% 8% 1% 22 ProdData3 09/24/2013-14:10:00-EDT y 90% 8% 1% Info 26306752329: The value of ckpt_usage_on_savvol for read-only checkpoints may not be consistent with the total_savvol_used. [nasadmin@VNXB ~]$ VNX SnapSure

38. Copyright © 2014 EMC Corporation. All Rights Reserved. Recycling SavVol Storage One way to create more SavVol space without extension is to refresh checkpoints 38 Unmount Checkpoint Delete Checkpoint Data Update Checkpoint to Active Remount Checkpoint VNX SnapSure

39. Copyright © 2014 EMC Corporation. All Rights Reserved. Managing Checkpoints 39VNX SnapSure

40. Copyright © 2014 EMC Corporation. All Rights Reserved. Modifying Checkpoint Schedules Schedules may be modified once they are active by accessing their Properties page 40VNX SnapSure

41. Copyright © 2014 EMC Corporation. All Rights Reserved. Memory Requirements for SnapSure SnapSure allocates up to 1 GB of Data Mover memory for checkpoint blockmaps  512 MB if DM RAM is less than 4 GB Both SnapSure and VNX Replicator require Data Mover memory allocation Blockmap entries are paged into Data Mover memory for fast access 41VNX SnapSure

42. Copyright © 2014 EMC Corporation. All Rights Reserved. Viewing Blockmap Status 42 [nasadmin@VNXB ~]$ server_sysstat server_3 -blockmap server_3 : total paged in = 0 total paged out = 1 page in rate = 0 page out rate = 0 block map memory quota = 1572864(KB) block map memory consumed = 392(KB) [nasadmin@VNXB ~]$ [nasadmin@VNXB ~]$ server_sysstat server_3 -blockmap server_3 : total paged in = 0 total paged out = 1 page in rate = 0 page out rate = 0 block map memory quota = 1572864(KB) block map memory consumed = 392(KB) [nasadmin@VNXB ~]$ VNX SnapSure

43. Copyright © 2014 EMC Corporation. All Rights Reserved. VNX SnapSure During this lesson the following topics were covered: Storage management for checkpoints Modifying SnapSure schedules Memory management for checkpoints Lesson 4: Summary 43VNX SnapSure

44. Copyright © 2014 EMC Corporation. All Rights Reserved. Summary Key points covered in this module: SnapSure creates a point-in-time view of a file system that is not a copy or a mirror image of the original file system CVFS is a navigation feature that provides NFS and CIFS clients with read-only access to online, mounted checkpoints from within the PFS namespace Checkpoint creation and refreshes can be scheduled on arbitrary, multiple hours of a day, days of a week or days of a month VNX SnapSure44