Archive for the ‘Technology’ Category

EMC Symmetrix: VCMDB and ACLX

March 23rd, 2010 5 comments

VCMDB: Volume Control Manager Database

ACLX: Access Control Logix

VCM: Volume Control Manager device (where the database resides)

VCM Gatekeeper: Volume Control Manager Gatekeeper (database doesn’t reside on these devices)

SFS Volumes: Symmetrix File System Volumes


If you work with EMC Symmetrix systems, you know the importance of VCMDB. Introduced with Symmetrix 4.0 and used in every generation after that, VCMDB stands for Volume Control Manager Database). Also in the latest generation of systems the VCM device is at times also referenced as VCM Gatekeeper.

VCMDB is a relatively small device that is created on the Symmetrix system that allows for hosts access to various devices on the Symmetrix. VCMDB keeps an inventory of which devices have access to which host (HBA’s). Without a VCMDB in place, host systems will not be able to access the Symmetrix. The VCMDB should be backed up on regular intervals and would be helpful in a rainy day.

The VCMDB device size grew along with new generations of Symmetrix systems that got introduced, primarily a means to keep a track of more supported devices (hypers / splits) on these platforms. With the introduction of Symmetrix V-Max, the VCMDB concept is now a bit changed to ACLX (Access Control Logix). Access Logix is being used on the Clariion systems for years now.


Here are a few things to consider with VCMDB

  • On the older Symmetrix systems (4.0, 4.8, 5.0 and 5.5), the VCMDB (device) is mapped to all the channels, host
  • In these systems the VCMDB access is typically restricted by Volume Logix or ACL (access control lists)
  • With the Symmetrix DMX, DMX2 Systems – Enginuity Code 5670, 5671 the VCM device only requires to be mapped to the Management stations
  • Management stations include SYMCLI Server / Ionix Control Center Server / Symmetrix Management Console
  • At all given times on the DMX, DMX2 platforms, the VCMDB would need to be mapped to at least one station to perform online SDDR changes. Alternatively this problem of not having device mapped to at least one host can also be fixed by the PSE lab
  • Mapping VCMDB to multiple hosts, channels may make the device venerable to crashes, potential tampering, device attributes and data change
  • You can write disable VCMDB to avoid the potential of the above
  • With these systems, the host can communicate to the VCMDB via Syscalls
  • The VCM Edit Director Flag (fibrepath) needs to be enabled for management stations to see VCM device
  • The database (device masking database) of the VCMDB resides on the SFS volumes. This feature was introduced with DMX-3 / DMX-4 (5772 version of microcode). A 6 cylinder VCM Gatekeeper device is okay to use with these versions of microcode.
  • Starting Symmetrix V-Max systems, the concept of ACLX was introducted for Auto Provisioning etc.
  • VCM volumes are required to be mirrored devices like SFS volumes


Various different types of VCMDB

Type 0, Type 1, Type 2, Type 3, Type 4, Type 5, Type 6

  • Type 0: Symmetrix 4.0, 32 Director System, 16 cylinder device size, Volume Logix 2.x
  • Type 1: Symmetrix 4.8, 64 Director System, 16 cylinder device size, ESN Manager 1.x
  • Type 2: Symmetrix 5.0/5.5, 64 Director System, 16 cylinder device size, ESN Manager 2.x
  • Type 3: Symmetrix DMX, supports 32 fibre/ 32 iSCSI initiator records per port, 24 cylinder device in size. Enginuity 5569, Solutions Enabler 5.2, Support 8000 devices
  • Type 4: Symmetrix DMX/DMX-2, supports 64 fibre/ 128 iSCSI initiator records per port, 48 cylinder device in size. Enginuity 5670, Solutions Enabler 5.3, Supports 8000 devices
  • Type 5: Symmetrix DMX/DMX-2, supports 64 fibre / 128 iSCSI initiator records per port, 96 cylinder device in size, Enginuity 5671, Solutions Enabler 6.0, Supports 16000 devices
  • Type 6: Symmetrix DMX-3, DMX-4, supports 256 fibre / 512 iSCSI initiator records per port, 96 cylinder device in size, Enginuity 5771, 5772 Solutions Enabler 6.0, Supports 64000 devices


Notes about various Types of VCMDB

  • Type 3 of VCMDB can be converted to Type 4 VCMDB (code upgrade from 5669 to 5670 to 5671)
  • Solutions enabler 5.2 and Solutions Enabler 5.3 can read/write Type 3 VCMDB
  • Solutions enabler 5.3 can read/write Type 4 VCMDB
  • VCMDB device is recommended to be a certain size, but it is okay to use a larger size device if no choices are available.


Converting various types of VCMDB using SymCLI

  • If the device cylinder size is equal with a conversion you are attempting, the following will help you convert your VCMDB from type x to type y.
    • Backup the device
    • symmaskdb –sid <symmid> backup –file backup
    • Check the VCMDB type using
    • symmaskdb – sid <symmid> list database
    • Convert from type 4 to type 5
    • Symmaskdb – sid <symmid> convert –vcmdb_type 5 –file Covertfilename


To initialize VCMDB for the first time on a Symmetrix System

Within Ionix Control Center

  • Click on the Symmetrix array you are trying to initialize the VCMDB
  • Select Masking then VCMDB Management and then initialize
  • Select a new backup and create a file name
  • Create a file name with .sdm extenstion
  • Click on Activate the VCMDB
  • VCMDB backups are stored at \home\ecc_inf\data\hostname\data\backup\symmserial\
  • Also it will be viewable within Ionix Control Center at Systems/Symmetrix/VCMDB Backups/


With SymCLI

  • To query the VCMDB database
    • symmaskdb –sid <symmid> list database
    • To backup and init an existing VCMDB database
      • symmaskdb – sid <symmid> init –file backup

More technical deep dive coming soon on various other topics…including ACLX.



EMC Symmetrix: Calculations for Heads, Tracks, Cylinders, GB

March 22nd, 2010 No comments

Symmetrix Disk Drive

Here is the quick and dirty math on EMC Symmetrix Heads, Tracks, Cylinder sizes to actual usable GB’s of space.

Based on different generations of Symmetrix systems, here is how the conversions work.

Before we jump into each model type, lets look at what the basics are, with the following calculations.





There are s number of splits (hyper) per physical device.

There are n number of cylinders per split (hyper)

There are 15 tracks per cylinder (heads)

There are either 64 or 128 blocks of 512 bytes per track


All the calculations discussed here are for Open Systems (FBA) device types. Different device emulations like 3380K, 3390-1, 3390-2, 3390-3, 3390-4, 3390-27, 3390-54 have different bytes/track, different bytes/cylinder and cylinders/volume.


Symmetrix 8000/DMX/DMX-2 Series

Enginuity Code: 5567, 5568, 5669, 5670, 5671

Includes EMC Symmetrix 8130, 8230, 8430, 8530, 8730, 8830, DMX1000, DMX2000, DMX3000 and various different configurations within those models.

GB = Cylinders * 15 * 64 * 512 / 1024 / 1024 / 1024

eg: 6140 Cylinder devices equates to 2.81 GB of usable data

6140 * 15 * 64 * 512 / 1024 / 1024 / 1024 = 2.81 GB

Cylinders = GB / 15 / 64 / 512 * 1024 * 1024 * 1024


15 = tracks per cylinder

64 = blocks per track

512 = bytes per block

1024 = conversions of bytes to kb to mb to gb.


Symmetrix DMX-3/DMX-4 Series

Enginuity Code: 5771, 5772, 5773

Includes EMC Symmetrix DMX-3, DMX-4 and various different configurations within those models.

GB = Cylinders * 15 * 128 * 512 / 1024 / 1024 / 1024

Eg: 65520 Cylinder device equates to 59.97 GB of usable data

65540 * 15 * 128 * 512 / 1024 / 1024 / 1024 = 59.97 GB

Cylinders = GB / 15 / 128 / 512 * 1024 * 1024 * 1024

15 = tracks per cylinder

128 = blocks per track

512 = bytes per block

1024 = conversions of bytes to kb to mb to gb


Symmetrix V-Max

Enginuity Code: 5874

Includes EMC Symmetrix V-Max and various different configurations within this model.

GB = Cylinders * 15 * 128 * 512 / 1024 / 1024 / 1024

Eg: 262668 Cylinder device equates to 240.47 GB of usable data

262668 * 15 * 128 * 512 / 1024 / 1024 / 1024 = 240.47 GB

Cylinders = GB / 15 / 128 / 512 * 1024 * 1024 * 1024

15 = tracks per cylinder

128 = blocks per track

512 = bytes per block

8 bytes = 520-512 used for T10-DIF

1024 = conversions of bytes to kb to mb to gb

Drive format on a V-Max is 520 bytes, out of which 8 bytes are used for T10-DIF ( A post on DMX-4 and V-Max differences).

HP Blades Day 2010: Paul Perez [CTO, Storageworks]

March 8th, 2010 No comments

During HP Blades Day 2010, we had a 30 min chat with Paul Perez – HP CTO, Storageworks Division.

Some of the highlights of the discussion with Paul are below

  • One master provisioning stack for all Storage
  • VDI solution from HP
  • Integration of IBRIX and Lefthand – Common Management Infrastructure
  • Proliant features of power management etc, to be passed onto the IBRIX and Lefthand with Convergence
  • Customer References
  • Bottlenecks in networking and storage today
  • Stranded pools of IP (Intellectual Property) within HP, Integration challenges
  • DataDomain
  • Integration of HP EVA teams with HP Unified Storage Division
  • Storage Tiering
  • “Memristor” – HP Labs
  • Industry Consolidation, business models
  • Convergence is Next Gen

The Video – Paul Perez Unplugged

Part 1

Part 2

Part 3

HP Blades Day 2010: HP POD Tour

March 4th, 2010 No comments

As part of the HP Blades Day, HP showed us a demo of the mobile datacenters that HP manufacturers and sells as Performance Optimized Datacenters (POD).

Though we didn’t get to see the manufacturing of this POD, they showed one of these POD’s sitting in their parking lot.

This thing was massive, a size of a tractor trailer with its weight around 100,000 pounds. Though these datacenters are not very mobile, they are used for customers that may need additional computation power or has on-demand computing. I would think these are probably available to buy by a customer and possibly lease.

Here is the video of HP POD Tour that was given to us at HP Houston, TX facilities, quite an impressive setup. Unfortunately we were not able to go inside the POD, we took pictures and movies outside the POD.

The only thing that needs to be connected to these POD’s are electric connection for power and cooling. Additional resources would include network/fiber connections etc. Not just one POD, but you can have a warehouse full of POD’s used as datacenter.

These typically cost 60 to 70% of a regular brick built datacenter and is at least 40% more efficient.

Hope you enjoy the video…




Disclaimer: This event is sponsored by HP and hosted in Houston, TX. HP paid all the flight, living and mostly food expenses. This is a bloggers – invitation only event. No products have been given by HP.