Getting Started | Advanced |
Table of Contents |
Related Topics |
How Source Side Deduplication Works Enabling Source Deduplication on a Storage Policy Copy Enabling Source Deduplication for a Client Signature Caching on the Source Enabling Signature Caching on the Client Filtering Source Side Deduplication Database Folder from Client Backups Prime the Deduplication Store with Data from Existing Stores |
Provides comprehensive information about Source Side Deduplication Support. Provides comprehensive information on deduplication. Provides basic information about Storage Policy Setup. Provides comprehensive information on storage policy copies. Provides basic information about viewing job history. Capabilities and Permitted Actions Provides list of the operations that are available to a user. |
By default, Source Deduplication is enabled in a storage policy copy. Use the following steps to enable Source Deduplication for an existing storage policy copy, if it was not enabled.
You can also enable the source side deduplication for a specific client.
Use the following steps only when Client Side Deduplication option is not enabled on the Storage Policy copy and you want to enable client side deduplication on specific clients.
|
![]() |
The signature lookup process can be optimized by setting up the cache locally on the source. When the local cache is setup, the signature is first looked up in the local cache. A remote lookup is initiated only when the signature is not available in the local cache.
For each backup, though the first lookup is a remote lookup, all subsequent lookups will be performed locally. Also, the remote lookups are performed in batches to optimize network usage. The signature cache can grow to a maximum of 32 GB.
The source side signature cache must have minimum of 500 MB of free disk space.
The following calculation can be used to determine the approximate amount of space required for the signature cache:
(Size of data / Deduplication block size) * 200 bytes
Note that signature caching is not supported on Linux s390, Macintosh and FreeBSD platforms.
Use the following steps to enable signature caching on the client:
|
![]() |
![]() |
During the backup process, it is recommended that to filter the source side deduplication database directory to avoid the backup failure.
If you have Service Pack 5A or higher version installed, the source side deduplication database directory automatically gets filtered.
If you have Service Pack version earlier than 5A, make sure to install the latest service pack or use the following procedure to filter the source side deduplication database folder:
|
![]() |
When source side deduplication storage policy is configured, compression is automatically enabled on the storage policy copy, but the compression always happen on the client.
For most of the data types the compression is recommended. This process works by compressing the blocks and then generating a signature hash on the compressed block.
Use the following steps to enable data compression for all subclients associated to storage policy:
|
![]() |
By default, for source side deduplication storage policy, compression always happens on client. To turn off the compression on a specific client computer, use the following steps
|
![]() |
Variable content alignment is performed on the client system and consequently you may experience some performance overhead, especially when used together with software compression. You can enable variable content alignment as follows:
|
![]() |
Whenever a new store is created, a fresh copy of the deduplicated data blocks is created for that store. However these data blocks may also be available in the sealed stores residing in the MediaAgent/data center. The Store Priming feature discovers such data blocks from the previously sealed stores and uses them to baseline the new store. In source-side deduplication, this saves the need for clients to transfer data blocks that are already available in the MediaAgent.
Use this feature to reduce the data transfer between clients that have source-side deduplication enabled and connect to the MediaAgent over a WAN.
This feature is not recommended if the clients exist in the data center or performance throughput is critical.
|
![]() |
On Unix Operating Systems, perform the following to use source side deduplication:
By default, Optimize for concurrent LAN backups option is enabled on the MediaAgent properties to ease up the IPC resource usage and to use more number of concurrent streams for data protection operations.
For the following agents, if you have source side deduplication enabled, Optimize for concurrent LAN backups option is not recommended. If you have this option enabled, the system ignores the option and will use a regular pipeline for data protection operations. If you wish to use this option to increase streams for concurrent backups, use MediaAgent side deduplication.
For Windows Agents such as DB2, Oracle, SAP Oracle or SAP MAXDB iDataAgents this option is not recommended.
For all Unix Agents except Unix File System iDataAgent this option is not recommended.
Use the following steps to enable/disable optimize for concurrent LAN backups on the MediaAgent:
|
![]() |
The following table displays the possible range of values for each parameter:
If "*" appears
after the parameter name, this indicates that you can increment the
value of the parameter based on the number of desired streams by using
the formula parameter value = 64 * number of desired streams as long as the "high-end" value of the range for the parameter is not exceeded. |
Parameters | Description | Possible Range of Values |
SEMMNI* | Defines the maximum number of semaphore sets in the entire system. | 1 – 65535 |
SEMMAP | Defines the maximum number of semaphore map entries. | 1 – 65535 (SEMMNI + 2) |
SEMMNS* | Defines the maximum semaphores in the system | 1 – 2147483647 [MAXINT] (Default value 128 is too low.) |
SEMVMX | Defines the maximum value of a semaphore | 32768 |
SHMMNI* | Defines the maximum number of shared memory segments in the entire system | 1 – 2147483647 [MAXINT] |
SHMMAX | Defines the maximum allowable size of one shared memory segment | 0 – 4294967295 (Available physical memory); recommended value is 2147483648 |
SHMSEG* | Defines the maximum number of shared memory segments that one process can attach | 0 - 32767 |
SEMMNU | Defines the maximum number of System V IPC system-wide processes that can have "undo" operations pending at any given time. | 1 - (nproc-4) [256]; preferred value: 1024 |
Use the following steps to modify the kernel parameters with System Administrator Menu (SAM) for HP-UX File System:
1. | From the unix prompt, enter the command to open the System Administrator Menu (SAM). | #sam |
2. | In the SAM utility window, double-click the Kernel Configuration icon. | |
3. | Double-click the Configurable Parameters icon. SAM will display a screen containing a list of configurable parameters, including current and pending values. | |
4. | Double-click on the parameter you wish to change. | |
5. | Click New Formula/Value option and type the recommended value. | |
6. | Click OK. | |
7. | Restart the computer to allow the changes to take effect. |
System Management Homepage (SMH) is the new tool introduced to manage HP-UX. Use the following steps to modify the kernel parameters using System Management Homepage (SMH) since the System Administration Manager (SAM) is deprecated in the current releases of HP-UX:
1. | From the unix prompt, enter the command to open the System Management Homepage (SMH) window. |
#smh |
2. | In the SMH Text User Interface, select k -Kernel Configuration and press Enter. |
DISPLAY variable is not set. Starting the Text User Interface. Please wait...HP-UX System Management Homepage (Text User Interface) SMH ---------------------------------------------------------- a - Auditing and Security c - Auditing and Security Attributes Configuration(new) d - Peripheral Devices e - Resource Management f - Disks and File Systems g - Display k - Kernel Configuration l - Printers and Plotters(new) m - Event Monitoring Service n - Networking and Communications p - Printers and Plotters s - Software Management u - Accounts for Users and Groups ---------------------------------------------------------- x-Exit smh w-WebLaunch 1-Help ENTER-Launch Functional Area v-SAM Log Viewer |
3. | Select the t - Tunables to view a list of configurable parameters, including current and pending values and press Enter. |
SMH->Kernel Configuration ---------------------------------------------------------- t - Tunables View or modify kernel tunables m - Modules View or modify kernel modules and drivers a - Alarms View or modify alarms for kernel tunables l - Log Viewer View the changes made to kernel tunables or modules u - Usage View usage of kernel tunables c - Manage Configuration View the options available to manage configuration b - Restore Previous Boot Values Restores Previous Boot Values for Tunable <-----------------------------------------------------------------------> x-Exit smh ENTER-Select ESC-Back 1-Help |
4. | Select the parameter you wish to change and press Enter. For Example, select semmni parameter. |
SMH->Kernel Configuration->Tunables (All) ---------------------------------------------------------------------------- Tunable Tuning Current Next Boot Default Usage Module Capability Value Value Value ===================================================================== semaem Static 16384 16384 16384 - pm_usync semmni Static 2048 2048 2048 1.4% pm_usync semmns Static 4096 4096 4096 3.7% pm_usync semmnu Static 256 256 256 - pm_usync semmsl Dynamic 2048 2048 2048 - pm_usync semume Static 100 100 100 - pm_usync semvmx Static 32767 32767 32767 - pm_usync shmmax Dynamic 1073741824 1073741824 1073741824 3.1% vm_asi shmmni Dynamic 400 400 400 2.2% vm_asi shmseg Dynamic 300 300 300 - vm_asi --------------------------------------------------------------------- x-Exit smh ESC-Back p-Pending b-Restore Previous Boot Values 2-kctune Manpage /-Search ENTER-Details m-Modify d-Dynamic 1-Help 3-Tunable Manpage |
5 |
Press m to modify the selected parameter.
Use the following formula to calculate the value for the parameter: parameter value = current value + (64 * number of desired streams)
|
SMH->Kernel Configuration->Tunables (All)->Details Details : semmni --------------------------------------------------------------------------------- Tunable semmni ============================================================================== Description Maximum number of semaphore sets on the system Dynamic no Subsystem pm_usync Default Value 2048 Current Value 2048 Planned Value 2048 Last Boot Value 2048 Constraints semmni >= 2 Constraints semmni <= 32767 Constraints semmni <= semmns Auto Tuning Not Supported Current Usage 28 ----------------------------------------------------------------------------------x-Exit smh m-Modify ESC-Back 1-Tunable Help |
6. |
|
SMH->Kernel Configuration->Tunables (All)->Details->Modify ------------------------------------------------------------------------ Tunable semmni Description Maximum number of semaphore sets on the system Module pm_usync Current Value 2048 [Default] Value at Next Boot 2048 [Default] Value at Last Boot 2048 Default Value 2048 Constraints semmni >= 2 semmni <= 32767 semmni <= semmns Can Change At Next Boot Only NOTE: If the new Value is specified as Default, the next boot value will be default value for the tunable as reccomended by HP. However, if the tunable is being autotuned then the value assigned will be determined dynamically by kernel during run-time. New setting[Expression/Value]: ___________________ New setting (evaluated): ___________________ [ Recalculate ] Back up the current configuration before applying change: (X) Yes ( ) No Reason for change : _______________________________________ [ Modify ] [ Preview ] [ Cancel ] ------------------------------------------------------------------------ |
7. | A Confirmation window will be displayed warning you that the requested changes have been saved and will take effect at next boot. Press Enter to continue. |
SMH->Kernel Configuration->Tunables (All)->Details->Modify ---------------------------------------------------------------------------------- mount: ignoring incomplete/incorrect entry for /dev/dsk/c0t0d0 in /etc/fstab NOTE: The requested changes could not be applied to the currently running system, for the following reasons: - The tunable 'semmni' cannot be changed without a reboot. * The requested changes have been saved, and will take effect at next boot. Tunable Value Expression semmni (now) 2048 Default (next boot) 2048 2048 mount: ignoring incomplete/incorrect entry for /dev/dsk/c0t0d0 in /etc/fstab Command Successful press Enter Key to continue |
8. | Restart the computer. |
The following table displays the possible range of values for each parameter:
If "*" appears
after the parameter name, this indicates that you can increment the
value of the parameter based on the number of desired streams by using
the formula parameter value = 64 * number of desired streams as long as the "high-end" value of the range for the parameter is not exceeded. |
Parameters | Description | Possible Range of Values |
SEMMSL* | Defines the minimum recommended semaphore value. | 1 – 2147483647 [MAXINT] |
SEMMNS* | Defines the maximum semaphores in the system. | 1 – 2147483647 [MAXINT] |
SEMOPM | Defines the maximum number of operations for each semaphore call. | 100 |
SEMMNI* | Defines the maximum number of semaphore sets in the entire system. | 1 – 65535 |
SHMMNI* | Defines the maximum number of shared memory segments in the entire system. | 1 – 2147483647 [MAXINT] |
SHMMAX | Defines the maximum allowable size of one shared memory segment. | 0 – 2147483648 [2 GB] (the high-end value is the recommended value) |
SHMALL | Defines the maximum total shared memory system-wide. | 2097152 |
Use the following steps to modify the kernel parameters:
1. | From the unix prompt, log on to the client as root. | |
2. | Navigate to the /proc/sys/kernel. | cd /proc/sys/kernel |
3. |
View the current values of the parameters in the sem
file. For example, view the values of all semaphore parameters. The output provides the current value for the following parameters in the order listed: SEMMSL, SEMMNS, SEMOPM, and SEMMNI. |
Example: cat sem 250 32000 32 128 In this example, SEMMSL=250, SEMMNS=32000, SEMOPM=32, and SEMMNI=128 |
4. |
Modify the required parameter. For example, modify the semmns parameter.
Use the following formula to calculate the value for the parameter: parameter value = current value + (64 * number of desired streams)
|
sysctl -w kernel.<parameter>="value" For example: sysctl -w kernel.semmns="2147483647" |
5. | Restart the computer to allow the changes to take effect. |
On a redhat linux computer, you can permanently modify the parameters using the following steps:
1. | From the unix prompt, log on to the client as root. | |
2. | Open the /etc/sysctl.conf file. | vi /etc/sysctl.conf |
3. |
Modify the required parameters. For example, modify the sem parameters.
Use the following formula to calculate the value for the parameter: parameter value = current value + (64 * number of desired streams)
|
sysctl -w
kernel.<parameter>="value1 value2 value3 value4". For Example: sysctl -w kernel.sem="4096 512000 1600 9005"
|
3. | Save the sysctl.conf file. |
Press the Esc key. Type :wq |
4. | Run the command to allow the changes to take effect. | sysctl -p |
The following table displays the possible range of values for each parameter:
If "*" appears
after the parameter name, this indicates that you can increment the
value of the parameter based on the number of desired streams by using
the formula parameter value = 64 * number of desired streams as long as the "high-end" value of the range for the parameter is not exceeded. |
Parameters | Description | Possible Range of Values |
SEMMNI* | Defines the maximum number of semaphore sets in the entire system. | 1 – 65535 |
SEMMSL* | Defines the minimum recommended semaphore value | 1 – 2147483647 [MAXINT] |
SEMOPM | Defines the maximum number of operations for each semaphore call | 100 |
SEMVMX | Defines the maximum value of a semaphore | 32767 |
SEMUME | Defines the maximum number of undo entries per process | 64 |
SEMAEM | Defines the maximum value for adjustment on exit | 16384 |
SHMMIN | Defines the minimum allowable size of a single shared memory segment |
0 ( Physical Ram) 1 |
SHMMNI* | Defines the maximum number of shared memory segments in the entire system | 1 – 2147483647 [MAXINT] |
SHMMAX | Defines the maximum allowable size of one shared memory segment | 0 – 4294967295 (recommended value is 2147483648) |
SHMSEG* | Defines the maximum number of shared memory segments that one process can attach | 0 - 32767 |
Use the following steps to modify the kernel parameters:
1. | From the unix prompt, create a backup copy of the /etc/sysconfigtab file. |
Example: cp /etc/sysconfigtab /etc/sysconfigtab.copy |
2. |
Use the ipcs
command to view the current values of the parameters. You can also view the kernel parameters in sysconfig file using the following commands:
|
Example: ipcs -m -s shm_max=1073741824 shm_mni=1024 shm_min=1 shm_seg=256 sem_mni=128 sem_msl=128 sem_opm=100 sem_ume=64 sem_vmx=32768 sem_aem=16384
sysconfig -s Example: sysconfig -s
|
3. |
Modify the required parameter value.
For example, modify the shm_mni parameter. Use the following formula to calculate the value for the parameter: parameter value = current value + (64 * number of desired streams)
|
sysconfig -r
<parameter>="value" Example: sysconfig -r shm_mni="2147483647" |
4. | Save the sysconfigtab file. |
Press the Esc key. Type :wq |
5. | Restart the computer. |
By default, the kernel parameters are set during the installation. However, you can also modify the parameters at a later point in time if needed.
The following table displays the possible range of values for each parameter for Solaris 9 and below:
If "*" appears
after the parameter name, this indicates that you can increment the
value of the parameter based on the number of desired streams by using
the formula parameter value = 64 * number of desired streams as long as the "high-end" value of the range for the parameter is not exceeded. |
Parameters | Description | Possible Range of Values |
SEMMNI* | Defines the maximum number of semaphore sets in the entire system. | 1 – 65535 (unsigned short) |
SEMMNS* | Defines the maximum semaphores in the system. | 1 – MAXINT MAXINT = 0x7fffffff (2147483647) |
SEMMSL* | Defines the minimum recommended semaphore value. | 1 – MAXINT MAXINT = 0x7fffffff (2147483647) |
SHMMIN | Defines the minimum allowable size of a single shared memory segment. | 0 (Physical Ram) 1 (It is recommended not to change the current value if set. If no value exists, set it to 1.) |
SHMMNI* | Defines the maximum number of shared memory segments in the entire system. | 0 – MAXINT MAXINT = 0x7fffffff (2147483647) |
SHMMAX | Defines the maximum allowable size of one shared memory segment. | 0 - MAXINT3264
MAXINT3264 = MAXINT (if 32-bit) or 0x7fffffffffffffff (if 64-bit) (If the current value is less than 4199304, then set it to 4199304.) |
SHMSEG* | Defines the maximum number of shared memory segments that one process can attach. | 0 - 32767 (signed short) |
SEMINFO_SEMMNU | Defines the total number of undo structures supported by the System V semaphore system. | 1024 |
Use the following steps to modify the kernel parameters for Solaris 9 and below:
1. | From the unix prompt, create a backup copy of the /etc/system file. | cp /etc/system /etc/system.copy |
2. | Open the /etc/system file. | vi /etc/system |
3. | Change the desired parameter value as per the range given
in the above table.
For example, set the value for semmni parameter to 55680 Use the following formula to calculate the value for the parameter: parameter value = current value + (64 * number of desired streams)
|
Example: set semsys:seminfo_semmni=55680 |
4. | Save the /etc/system file. |
|
5. | Restart the computer to allow the changes to take effect. |
The following table displays the possible range of values for each parameter for Solaris 10 and above:
project.max-shm-memory | Defines the total amount of shared memory allowed for a project. | [Default = 25% of the physical memory]
It is recommended not to set this value. However, if you have to set the control to accommodate other resource consumers, ensure that the value is not less than 2MB = [2097152]. |
project.max-shm-ids* | Defines the maximum number of shared memory IDs allowed for a project | 16777216 [Default = 128] |
project.max-sem-ids* | Defines the maximum number of semaphores allowed for a project | 16777216 [Default = 128] |
For Solaris 10 and above, you can use any of the following commands to modify the kernel parameters:
Use the following steps to modify the kernel parameters in Solaris 10 and above versions using the projmod command:
1. | From the unix prompt, type the
projmod command. projmod [-n] [-f filename] [-p projid [-o]] [-c comment] [-a|-s|-r] [-U user [,user...]] [-G group [,group...]] [[-K name[=value[,value...]...]]] [-I new_projectname] project |
Example: projmod -s -K "project.xxx" user.root |
2. | Change the desired parameter value as per the range given
in the above table. For example, set the value for project.max-shm-ids parameter Use the following formula to calculate the value for the parameter: parameter value = current value + (64 * number of desired streams)
|
Example: projmod -s -K "project.max-shm-ids=(priv,1280,deny)" user.root |
3. | Restart the computer to allow the changes to take effect. |
Use the following steps to modify the kernel parameters in Solaris 10 and above versions using the prctl command:
1. | From the unix prompt, type the
prctl command. prctl [-P] [-t[basic| privileged| system]] [-n name] [-v value] [-e| d action] [-p pid] [-i idtype] id... |
Example: projmod -n project.xxx -v xxx -r -i project user.root |
2. | Change the desired parameter value as per the range given
in the above table.
For example, set the value for project.max-shm-ids parameter Use the following formula to calculate the value for the parameter: parameter value = current value + (64 * number of desired streams)
|
Example: prctl -n project.max-shm-ids -v 1280 -r -i project user.root Output: project: 1: user.root project.max-shm-ids privileged 1280 - deny - project.max-shm-ids system 16777216 max deny – |
3. | Restart the computer to allow the changes to take effect. |
Deduplication requires following licenses based on the License Type:
Review the following consideration when using Source Side Deduplication:
Operation | Description |
Inline Copy | Inline Copy is not supported for Source Side deduplicated storage policy copies. |
Store Priming | Store Priming is not supported for Storage Policy Copy configured with Cloud Storage library. |