1. Associate the BCV Device for pairing: To perform standard/BCV pairing, the standard and BCV mirror devices of your production images must be members of the same device group (Note:- Already discussed in previous post about creating device group and pairing devices). symbcv –g DgName –sid SymmID associate dev 0ABC BCV001 Or to associate a range of devices to a device group, enter: symbcv –g DgName –sid SymmID associateall dev –RANGE 0ABC:0DEF Note:- -sid SymmID is optional if you have already defined device group in symcli environment varaiable. 2. Unmount the BCV device: Prior to using devices for BCV operations, the BCV device should be Windows formatted and assigned a drive letter. If using basic disks on the Windows platform, you must unmount the BCV devices. If using dynamic disks, you must deport the entire TimeFinder device group. For basic disks, use the syminq command to determine the SymDevName of the potential BCV device. For dynamic disks,use the TimeFinder symntctl command to determine the volume and disk group name as follows: symntctl list –volume [dg DgName] Note that the term device group and dynamic disk group are the same applied to this command. Unmount the selected BCV device as follows (with TimeFinder command): symntctl unmount –drive z Where z equals the designated drive letter. If an error occurs, check for an “openhandle” and clear this condition. For Veritas dynamic disks only, you must deport the disk group and rescan using the following commands: vxdg deport –g DgName symntctl rescan 3. Fully Establish BCV and STD: To obtain a copy of the data on a standard device, the BCV device of the pair must be established. To initiate a full establish on a specific standard/BCV device pair, target the standard device: symmir –g DgName –full establish DEV001 Fully Establish all pairs in a group. To initiate a full establish on all BCV pairs in a device group, enter: symmir –g DgName –full establish Verify the completed (synchronized) establish operation. To verify when the BCV pairs reach the full copied or Synchronized state, use the verify action as follows: symmir –g DgName –i 20 verify With this interval and count, the message is displayed every 20 seconds until the pair is established. Rescan the drive connections. For Dynamic disks only on a Windows host, you should rescan for drive connections visible to the host: symntctl rescan After any standard/BCV pair has been fully established and subsequently split, to save establish (resync) time, you can perform an establish operation omitting the -full option, which updates the BCV copy with only the changed tracks that occurred on the standard device during the elapsed BCV split time. To perform an incremental establish, omit the –full option, targeting the standard device symmir -g DgName establish DEV001 Optionally, you can also collectively target all devices in a device group, composite group, or defined devices in a device file: symmir –g DgName establish [-full] symmir –g CgName establish [-full] symmir –file FileName establish [-full] 4. Prepare (freeze) Production database for a TimeFinder Split: To prepare to split the synchronized BCV device from the production standard device, you must suspend I/O at the application layer or unmount the production standard prior to executing the split operation. symioctl freeze –type DbType [object] Ensure any residual cache on the Production host is fully flushed to disk. To insure all pending unwritten production file system entries are captured, enter TimeFinder command: symntctl flush –drive z Wait 30 to 60 seconds for the flush operation to complete. 5. Split the BCV devices: To split all the BCV devices from the standard devices in the production device group, enter: symmir –g DgName split To split a specific standard/BCV pair, target the logical device name in the group, enter: symmir –g DgName split DEV001 6. Verify the split operation completes: To verify when the BCV device is completely split from the standard, use the verify action as follows: symmir –g DgName –i 20 verify –split -bg With this interval and count, the message is displayed every 20 seconds until the pair is split. 7. Rescan for dynamic disks: For dynamic disks only, you should rescan for drive connections visible to the host: symntctl rescan 8. Mounting BCV device: After splitting the BCV device, you can mount the device with captured data on another host and reassign the drive letter. For basic disks, use the TimeFinder command: symntctl mount –drive z –dg DgName For Dynamic disks, use the TimeFinder command: symntctl mount –drive z –vol VolName –dg DgName | -guid VolGuid For VERITAS dynamic disk only, you must deport the disk group and rescan, as follows: vxdg deport –dg DgName symntctl rescan For Dynamic disk only (without Veritas), you can use the Microsoft diskpart command to select the disk and import the device using the online and import actions. Note:- symntctl command available in TimeFinder/IM ( Integration Module).
of the pair:
What is “Tier 0” in Storage Environments?
Tier "0" is not new in storage market but for implementation purposes it has been difficult to accommodate because it requires best performance and lowest latency. Enterprise Flash disks (Solid State Disks) capable to meet this requirement. It is possible to get more performance for company most critical applications. The performance can be gained through using Flash drives supported in VMAX and DMX-4 systems. Read More →
You can identify the FA port available on Symmetrix:
symcfg list –connections.
Verify port flag settings-
symcfg list –fa
( FA-Number and Port where your host connected/zoned)
The following FA bits/flag require being set/Enable:
i) Common Serial Number (C)
ii) VCM State (VCM) --- (ACLX for V-MAX)
iii) SCSI 3 (SC3)
iv) SPC 2
v) Unique World Wide Name (UWWN)
vi) Auto-negotiation (EAN)
vii) Point to Point (P)
Note :- FA bit/flag requirement may vary depending on Symmetrix, but most of times you require to enable above bit for VMware host.
Create a command file for setting FA port flags, call it faflags.cmd with the below entry:
# For C-Bit
set port FA:Port Common_Serial_Number=enable;
set port FA:Port Common_Serial_Number=enable;
# For VCM-Bit
set port FA:Port VCM_State=enable;
set port FA:Port VCM_State=enable;
# For SC3-Bit
set port FA:Port scsi_3=enable;
set port FA:Port scsi_3=enable;
# For SP-2-Bit
set port FA:Port SPC2_Protocol_Version=enable;
set port FA:Port SPC2_Protocol_Version=enable;
# For UWWN-Bit
set port FA:Port Unique_WWN=enable;
set port FA:Port Unique_WWN=enable;
# For EAN-Bit
set port FA:Port Auto_Negotiate=enable;
set port FA:Port Auto_Negotiate=enable;
# For PTOP-Bit
set port FA:Port Init_Point_to_Point=enable;
set port FA:Port Init_Point_to_Point=enable;
Once you prepare command file, you can commit the file:
symconfigure –sid
Verify port flag settings once again, required FA flags should have be enabled by now-
symcfg list –fa
You are ready to provision SAN storage for VMware host now…
3) Virtual Provisioning Phase 2 - Support for MirrorView and SAN Copy replication on thin LUNs has been added.
PowerPath Migrator Enabler is a host-base migration tools from EMC that allows you to migrate data between storage systems with little or no interruption to data access. This tool can be use in conjunction with other underlying technology such as EMC Invista, Open Replicator. PPME use the PowerPath filter dirvers to provide non-disruptive or minimally disruptive migrations. Only specific host plateforms are supported by PPME. Please check EMC support matrix for supported host systems. One of the PPME features that supports pseduo-to-pseduo, native-to-native and native-to-pseudo device migration.
Consider the following when designing and configuring PPME:
Ø Remote devices do not have to be the same RAID type or meta-configuration.
Ø Target devices must be the same size or large than the source control device.
Ø Target directors act as initiators in the SAN.
Ø Contrary to the recommendations for Open Replicator, the source device remains online during the “hot pull.”
Ø The two storage systems involved in the migration must be connected directly or through a switch, and they must be able to communicate.
Ø Every port on the target array that allows access to the target device must also have access to the source device through at least one port on the source array. This can be counter to some established zoning policies.
Ø Since PPME with Open Replicator uses FA resources, determine whether this utility will be used in a production environment. In addition, consider FA bandwidth assessments so that appropriate throttling parameters (that is, pace or ceiling).
Ø The powermig throttle parameter sets the pace of an individual migration by using the pace parameter of Open Replicator:
Ø Faster (lower throttle) makes the migration faster, but may impact application I/O performance.
Ø Slower (higher throttle) makes the migration slower.
Ø The default is five (midpoint).
Ø When setting a ceiling to limit for Open Replicator throughput for a director/port:
Ø The ceiling value is set as a percentage of a director/port’s total capacity.
Ø The ceiling can be set for a given director, port, director and port, or all director and ports in the Symmetrix array.
Ø To set ceiling values, you must use symrcopy set ceiling directly (powermig does not provide a way to do this)
Ø Once the hot pull has completed, remove or re-use the source device.
Ø Do not forget to “clean up” the zoning once you have completed migration activities.
Hope this will be useful in migration planning or selecting migration tools. I will try to explain in deatil in coming post such as PPME with Open Replicator, Solution Enabler etc..
Tier "0" is not new in storage market but for implementation purposes it has been difficult to accommodate because it requires best performance and lowest latency. Enterprise Flash disks (Solid State Disks) capable to meet this requirement. It is possible to get more performance for company most critical applications. The performance can be gained through using Flash drives supported in VMAX and DMX-4 systems. One Flash drive can deliver IOPS equivalent to 30 15K RPM hard disk drives with approximately 1 ms application response time. Flash memory achieves performance and the lowest latency ever available in the enterprise class storage array.
Tier “0” application can be closely coupled with other storage tier within Symetrix series for consistency and efficiency, reducing cost of company for manual data layout or data migration from old disk to new high speed disk.
Tier “0” storage can be used to accelerate online transaction processing, accelerating performance with large indices and frequently accessed database tables i.e. Oracle, DB2 databases and SAP R/3. Tier 0 can also improve performance in batch processing and shorten batch processing in windows environments.
Tier “0” storage performance will help application that needs the lowest latency and response time possible. The following applications can get benefited through using Tier 0 storage:
- Algorithmic trading
- Data modeling
- Trade optimization
- Realtime data/feed processing
- Contextual web advertising
- Other realtime transaction systems
- Currency exchange and arbitrage
Tier “0” storage is most beneficial with random read miss application. If random read miss percentage is low, application will not see any performance difference since writes and sequential reads/writes already leverage Symmetrix cache to achieve the lowest possible response time.
For example, if the read hit percentage is high >90 % as compared to read misses, such application like DSS, Streaming media, improvements provided by Tier 0 storage will not likely be enough to be cost-effective.
About Me
- Diwakar
- Sr. Solutions Architect; Expertise: - Cloud Design & Architect - Data Center Consolidation - DC/Storage Virtualization - Technology Refresh - Data Migration - SAN Refresh - Data Center Architecture More info:- diwakar@emcstorageinfo.com