Purpose:

This document is meant as a quick reference guide to best practice recommendations for FAST VP.  Please review the associated product guide and best practices white paper for a more detail discussion on various FAST/VP configuration and options.  The online help for Unisphere for VMAX and SMC are also good references for procedures to setup and configure FAST VP.

General Recommendations

  1. Bind all tdevs to the Fibre Channel tier
  2. Do not Preallocate tdevs.  Preallocated, but unwritten, extents will be demoted to lowest tier
  3. Set “Max. Subscription Percent” for the EFD and SATA pool to 0, to prevent accidental binding to the EFD and SATA pool
  4. Set “Pool Reserved Capacity” for the EFD and SATA pool to 1%,
  5. Fast/VP can be enabled on the frame prior to data migrations,
  6. Associate storage groups for migrated hosts after the migration cutover is complete.
  7. Defining and managing less FAST VP policies are generally better than more policies.
  8. Leverage tier advisor or presales sizing to get a starting point of to define a initial FAST VP Policy
  9. The following FAST VP policies can also be used as a initial starting point 
  10. Gold Policy                           =>           EFD 15%, FC  90%, SATA 60%,
  11. Silver Policy                          =>           EFD 10%, FC  80%, SATA 80%
  12. Bronze Policy                       =>           EFD   5%, FC  40%, SATA 100%
  13. Start by placing all storage groups in the Silver policy
    1. Check FAST VP compliance reports to determine tier usage and performance requirements for the associate SG
      1. Promote SG that require more EFD to the Gold Policy
  14. Look to set storage group IO limits on QA/Dev hosts to limit SATA pool drive utilization.
    1. To free up space for subsequent migrations.  1st look for less critical hosts that can be moved to a lower policy.
  15. For data migrations with multiple cutover waves to the frame:
    1. Prior to initiating data copy, ensure there is enough spare capacity in the FC pool to receive the full capacity of the migration wave.
    1. Review VP pool response time and spindle utilization prior to starting to confirm existing FAST VP policy tier % makes sense for your environment.  Adjust tier % as required to maintain a healthy balance between FC pool consumption and SATA pool spindle utilization.
    1. Setting a higher “Pool Reserved Capacity” (ie. 20-30%) may also be used to free up capacity in the pool.  Use with care, as this will potentially cause “warm” extents to be pushed to the SATA pool utilization
    1. EFD pool % in policies can be increased after all migrations are completed to optimize performance

Performance time window

  • Use default, performance metrics are collected 24 hours a day, every day

Data movement time window

  • Allow FAST VP to perform movements 24 hours a day, every day.

The Workload Analysis Period (WAP)

  • A longer WAP will factor less-recent host activity into FAST VP promotion/demotion scores.
  • Shorter WAP, allows FAST VP to react to changes more quickly, but may lead to greater amounts of data being moved between tiers.
  • Use default WAP (168 hrs)

The Initial Analysis Period (IAP)

  • At the initial deployment of FAST VP, it may make sense to set the IAP to 168 hours (one week)
  • During steady state, the IAP can be reduced to 24 hours (one day)

The FAST VP Relocation Rate (FRR)

  • For the initial deployment of FAST VP, start with a more conservative value for the relocation rate, perhaps 7 or 8
  • When it is seen that the amount of data movements between tiers is less, the FRR can be set to a more aggressive level of 5 or higher.
  • To determine expected movement rate in GB/Hour and FRR, the formula is as follow <Rate> GB = 10GB/FRR

VP Allocation by FAST Policy (require 5876, off by default)

  • As a best practice, it is recommended that VP Allocation by FAST Policy be enabled


Storage group priority

  • This priority value can be between 1 and 3, with 1 being the highest priority. The default is 2
  • The best-practice recommendation is to use the default priority of 2 for all storage groups associated with FAST VP policies

SRDF recommendations

  • enable “VP Allocation by FAST Policy” for R2
  • FAST VP SRDF coordination (Enabled by storage groups @ R1, independent FAST VP Policy defined @ R2)
    • Enable coordination only if R2 performance at the time of failover is critical to the client.

Gathering Data (FAST VP Configuration)

Execute a “symcfg discover” prior to the cmds below

symfast -sid xxxx list -control_parms                             – List FAST/VP configuration settings

symfast -sid xxxx list -state -vp                                        – List current FAST/VP SW state

symtw -sid xxxx list                                                            – List fast data movement and performance monitor time windows

symfast list -sid xxxx -fp -v                                               – List Fast/VP policy and storage groups associated to each policy.

symfast -sid xxxx list -association                                   – List FAST VP Storage Group association and priority

symfast -sid xxxx list -association -demand                  – List FAST VP Storage Group Compliance reports, from a SG perspective

symfast -sid xxxx list -tech ALL -demand -vp -v         – List FAST VP Compliance reports, from a drive Tech/tier perspective

symtier -sid xxxx list -vp                                                    – List VP tiers configuration and utilization summary

symtier -sid xxxx list -vp -v                                               – List VP tiers configuration and utilization details with % full info

Gathering Data (Virtual Provisioning Data)

Execute a “symcfg discover” prior to the cmds below

symcfg -sid xxxx list -pool -thin -detail -gb                                    – List VP thin Pool allocation summary in GB (usable/free/ % full)

symcfg -sid xxxx list -pool -thin -detail -gb    -v                            – List VP thin Pool device allocation detail in GB

symcfg -sid xxxx show -pool <name> -thin –all -detail -gb        – List a specific VP thin Pool device allocation detail in GB

symcfg -sid xxxx list -tdev  -bound  -detail -gb                              – List all tdevs (in GB) with VP pool binding associations

symcfg -sid xxxx list -tdev -pool <name> -gb                                – List all tdevs (in GB) bound to the specified VP pool

symdev -sid xxxx list -pinned                                                           – List any symdev that are pinned to a specific tier

symdev -sid xxxx list -datadev -tech <EFD | FC | SATA>           – List all thin data devices associated with a disk technology

symdev -sid xxxx list -datadev -nonpooled                                   – List all thin data devices not associated with a VP pool

symdisk -sid xxxx list -dskgrp_summary                                       – Summary list of all disks defined in the frame by disk groups

symsg -sid xxxx list                                                                             – List storage groups and if SG is associated with a FAST VP policy

Gathering Data (Symapi DB for Offline Review)

To look at the data offline, the array configuration information must 1st be sync with the symapi_db.bin file

Execute a “symcfg discover” prior to the cmds below

symcfg -sid xxxx sync -fast                                              – Sync the symapi_db file with FAST info gathered from the frame

symcfg -sid xxxx sync -vpdata                                        – Sync the symapi_db file with VP info gathered from the Frame

symcfg -sid xxxx sync -tier                                                – Sync the symapi_db file with tier info gathered the frame

On UNIX, the default pathname for the configuration database file is:

                /var/symapi/db/symapi_db.bin

On Windows, the default configuration database path is:

                C:\Program Files\EMC\SYMAPI\db\symapi_db.bin

Set the following environment variables on the local symcli host to point to the symapi_db offline

                SYMCLI_OFFLINE                : 1

                SYMCLI_DB_FILE                : symapi_db.bin

Limits and Restrictions

  1. FAST VP Policies may contain up to 4 tiers (Up to 3 internal and 1 external <FTS> with 5876 code)
  2. 2. Internal tiers should be of different drive technology types   (Each internal tier can consist of up to 4 VP pools)
  3. VMAX support up to 256 policies with 32 alpha-NUMERIC CHARACTERS (‘-’ AND ‘_’  are allowed)
  4. An array can contain up to a maximum of 8192 storage groups.
  5. Each storage group can contain a maximum of 4096 devices.
  6. Up to 1000 storage groups can be associated with FAST VP policies
  7. Cascaded storage groups require 5876 code and SE 7.5 or greater
  8. Up to 32 child storage groups can be added to 1 parent storage group
  9. FAST VP only supports association with storage groups that contain devices

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