R_MOD_20-VNX_SnapSure

Report
VNX SnapSure
Upon completion of this module, you should be able to:
• Describe VNX SnapSure theory and operations
• Configure SnapSure
• Plan and manage SnapSure
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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VNX SnapSure
Lesson 1: VNX SnapSure Theory of Operations
This lesson covers the following topics:
• Purpose of SnapSure
• Key components of SnapSure
• SnapSure theory of operations
• VNX SnapSure storage usage
• Checkpoint scheduling
Copyright © 2014 EMC Corporation. All Rights Reserved.
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SnapSure Overview
Purpose of SnapSure
• Provides a point-in-time view of a file system
known as a “checkpoint”
• Used mostly in backups and file system restores
Two views of a file system
• Live data viewed directly from production file
system
• Point-in-time, read-only view from a checkpoint
of the production file system (PFS)
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VNX SnapSure
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User’s Views of Data
Monday View
Read-only
Tuesday View
Read-only
Wednesday View
Production
Read-only
Live
biz_proposal
biz_proposal
biz_proposal
biz_proposal
Production File System
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Checkpoints
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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 Stores original data blocks to preserve the point in time view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
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Theory of Operation: Part 1 of 7
• Creating a checkpoint
SavVol
PFS
Bitmap
0 0 0 0 0 0
Blockmap1
PFS SavVol
A B C D E F
Ckpt 1
Data Storage Area
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VNX SnapSure
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Theory of Operation: Part 2 of 7
SavVol
2
Bitmap
PFS
0 0 0 0 0 0
Blockmap1
PFS SavVol
A B C D E F
1
H
K
Ckpt 1
Data Storage Area
1. Write request is made
2. Check the Bitmap value
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Theory of Operation: Part 3 of 7
• Writing to the PFS
PFS
SavVol
Bitmap
0 1 0 0 1 0
1
2
3
E
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5
Hold
H
2
B
A B C D E F
4
Blockmap1
PFS SavVol
2
5
Ckpt 1
1
K
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
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Theory of Operation: Part 4 of 7
• Creating a second checkpoint
PFS
SavVol
Bitmap
0 0 0 0 0 0
Ckpt 1
A H C D K F
Blockmap1
Blockmap2
PFS SavVol PFS SavVol
2
5
B
1
2
E
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Ckpt 2
• Bitmap is reset to zero values
• A new blockmap is created for Ckpt2
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Theory of Operation: Part 5 of 7
• Writing to the PFS with Ckpt2
SavVol
Bitmap
PFS
4
Ckpt 1
1 1 0 0 0 1
5
Blockmap2 3
Blockmap1
PFS SavVol PFS
2
5
1
2
B
F
E
SavVol
1
2
6
A
3
4
5
H
Copyright © 2014 EMC Corporation. All Rights Reserved.
Ckpt 2
New
2
A H C D K F
J L
Hold
S
1
1. Issue write hold
2. Copy data into SavVol
3. Update Ckpt2’s blockmap
4. Update bitmap values
5. Release write hold
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Theory of Operation: Part 6 of 7
• Reading from active checkpoint
SavVol
Bitmap
Ckpt 1
1
Old
1 1 0 0 0 1
Blockmap1
Blockmap2 3
PFS SavVol PFS SavVol
2
5
B
F
1
2
E
1
2
6
A
3
4
5
H
Copyright © 2014 EMC Corporation. All Rights Reserved.
PFS
J L C D K S
2
Ckpt 2
A H C D K F
Active
3
1. Read Bitmap values
2. “0” - Retrieve data from PFS
3. “1” - Retrieve data from SavVol
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Theory of Operation: Part 7 of 7
• Reading from old checkpoint
SavVol
Bitmap
1
PFS
Ckpt 2
2
1 1 0 0 0 1
Active
J L C D K S
Ckpt 1
A B C D E F
3
Blockmap1
Blockmap2
PFS SavVol PFS SavVol
2
5
B
F
1
2
E
1
2
6
A
3
4
5
H
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Old
1. Read older checkpoint’s blockmap
2. Aggregate oldest values
3. Verify active checkpoint’s blockmap
for location
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SavVol Storage Considerations
• All checkpoints of a PFS share the same SavVol
Automatically-created
SavVols
• Uses the same storage pool as the
PFS unless otherwise specified
Manually-created SavVols
• A manually-created
metavolume is selected during
checkpoint creation
• If PFS ≥ 20GB then SavVol = 20GB
• If PFS < 20GB and PFS > 64MB then
SavVol = PFS size
• If PFS ≤ 64MB then SavVol = 64MB
Copyright © 2014 EMC Corporation. All Rights Reserved.
• Best practice is to create a
SavVol that is 10% of PFS size
• Offers more control on which
disks to place the SavVol
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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
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VNX SnapSure
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Checkpoint Scheduling Overview
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
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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VNX SnapSure
Lesson 1: Summary
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
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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VNX SnapSure
Lesson 2: Configuring SnapSure
This lesson covers the following topics:
• Checkpoint creation and verification
• Displaying existing checkpoints
• Accessing the checkpoint
• Configuring checkpoint scheduling
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VNX SnapSure
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Creating a Checkpoint
• Data Protection > Snapshots > File System Checkpoints
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Displaying Checkpoints
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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_<Data_Mover_timezone>
 CVFS names can be changed when remounting the checkpoint
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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NFS Client Checkpoint Access
[[email protected] 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
[[email protected] student8]#
[[email protected] student8]# ls -la .ckpt
.ckpt directory has to
total 33
be explicitly specified
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
Checkpoints
appear
[[email protected]
student8]#
as directories
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VNX SnapSure
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NFS Client Checkpoint Access (continued)
[[email protected] student8]# cd .ckpt
[[email protected] .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
[[email protected] .ckpt]#
[[email protected] .ckpt]# cd 2013_09_18_21.46.01_GMT
[[email protected] 2013_09_18_21.46.01_GMT]#
[[email protected] 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
[[email protected] 2013_09_18_21.46.01_GMT]#
[[email protected] 2013_09_18_21.46.01_GMT]#
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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CIFS Client Checkpoint Access
• In the address field of Windows Explorer, enter \.ckpt to list the
checkpoints associated with the file system share
Manually type the
path to .ckpt
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VNX SnapSure
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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
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VNX SnapSure
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Displaying Checkpoint Schedules
• Data Protection > Snapshots > File System Checkpoints > Schedules Tab
• Schedule states
 Active
 Pending
 Paused
 Complete
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VNX SnapSure
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Creating a Checkpoint Schedule
Use relative prefix to
make script writing easier
Checkpoint names
may be assigned
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SnapSure Considerations
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
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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VNX SnapSure
Lesson 2: Summary
During this lesson the following topics were covered:
• Checkpoint creation and verification
• Displaying existing checkpoints
• Accessing the checkpoint
• Configuring checkpoint scheduling
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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VNX SnapSure
Lesson 3: Planning SnapSure
This lesson covers the following topics:
• Planning checkpoint schedules
• Performance considerations
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VNX SnapSure
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Schedule Planning
Important considerations when planning
a checkpoint schedule
• 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
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VNX SnapSure
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PFS Performance Implications
Checkpoint
Creation
• Only reads allowed on the PFS, all
write activity will be suspended
Checkpoint
Deletion
• Only reads allowed on the PFS, all
write activity will be suspended
Checkpoint
Restore
• All PFS I/O activity is suspended
during restore initialization
Copy On
First Write
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• Write I/O is suspended until original
data is copied to the SavVol
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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
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VNX SnapSure
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SavVol Performance and Disk Type
• SavVol writes are sequential, while reads are random
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
Copyright © 2014 EMC Corporation. All Rights Reserved.
NL-SAS
• 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
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VNX SnapSure
Lesson 3: Summary
During this lesson the following topics were covered:
• Planning checkpoint schedules
• Performance considerations
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
34
VNX SnapSure
Lesson 4: Managing Checkpoints
This lesson covers the following topics:
• Storage management for checkpoints
• Modifying SnapSure schedules
• Memory management for checkpoints
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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Checkpoint Storage Consumption
• Checkpoint Properties
page
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VNX SnapSure
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Listing Checkpoints via CLI
[[email protected] ~]$ fs_ckpt fs16 -list
id
ckpt_name
creation_time
16
17
18
20
21
22
Monday
Tuesday
Wednesday
ProdData1
ProdData2
ProdData3
09/18/2013-05:33:52-EDT
09/18/2013-05:39:20-EDT
09/18/2013-05:45:15-EDT
09/24/2013-12:10:00-EDT
09/24/2013-13:10:00-EDT
09/24/2013-14:10:00-EDT
inuse fullmark
y
y
y
y
y
y
90%
90%
90%
90%
90%
90%
total_
savvol_
used
8%
8%
8%
8%
8%
8%
ckpt_
usage_on
savvol
1%
1%
1%
1%
1%
1%
Info 26306752329: The value of ckpt_usage_on_savvol for read-only checkpoints may not be
consistent with the total_savvol_used.
[[email protected] ~]$
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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Recycling SavVol Storage
• One way to create more SavVol space without extension is to
refresh checkpoints
Unmount
Checkpoint
Delete
Checkpoint
Data
Copyright © 2014 EMC Corporation. All Rights Reserved.
Update
Checkpoint
to Active
Remount
Checkpoint
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Managing Checkpoints
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VNX SnapSure
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Modifying Checkpoint Schedules
• Schedules may be modified once they are active by accessing their
Properties page
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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
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VNX SnapSure
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Viewing Blockmap Status
[[email protected] ~]$ 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)
[[email protected] ~]$
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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VNX SnapSure
Lesson 4: Summary
During this lesson the following topics were covered:
• Storage management for checkpoints
• Modifying SnapSure schedules
• Memory management for checkpoints
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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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
Copyright © 2014 EMC Corporation. All Rights Reserved.
VNX SnapSure
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