MY NOTES
- HBA Company – Emulex,
Q- logic
- Switches – Brocade,
CISCO
- SAN Surface
is used to manage the Brocade switch.
- Cisco is
managed by HBA anywhere / OCM (one command manager)
- Zoning –
Connecting initiator node and target node.
- ALIAS – nick names
for WWNs.
- How we login into switch: Telnet
& SSH are used to login into switch.
- MDS – Cisco
- B-Series – Brocade
- Cisco Fabric manager, EMC
san manager & device manager are the management tools for switch.
- Adding a LUN to Multiple
storage group is not recommended configuration because this will allow
multiple hosts to have simultaneous access to LUN.
- DMX Features – Non
Disruptive upgrade, Multi site disaster recovery, enterprise consistent.
- In DMX each storage bay
consists of 240 drives.
- CMI is used to setup the
Management IP.
- Domain: Combining
all the storages under one roof to manage.
- Thin
LUNs: On-Demand Storage Allocation.
- Thick
LUNs: Fully allocated at the time of creation.
- Minimum No of disks: 3
(Raid-5), 4(Raid-6), 3 or 9 (Raid-3)
- Raid Group Limit to 16
Disks.
- Raid-6: accept even number
of disks, defragment is not allowed.
- How to access LUNs: kept LUN
in storage group, assign HOST to SG.
- CLI (command line interface)
used for Configure, Manage and Monitor Blades.
- Proactive
Hot Spare: Replacement of a drive without operating in degraded mode.
- Information and Error Msg
are logged in Ktrace or event logs.
- Replication
Manager: Manage and automate snapshots and clone for various
replication product. Ex: Microsoft Exchange and SQL server Volumes.
- Recovery
Point CDP: It maintain a history journal of all changes that can be used
to roll back the mirrors to any point in time.
- SanpSure: Create
Checkpoint , view file system
- SanpView: To view the File System, Point in Time
Copies of LUNs.
- Types
of Tickets (BMC Ready S/W): Incident
– Which are not planned.
Change
– Which are planned.
Problem
– Happen in sudden or any disaster.
- FAST: Fully
Automated Storage Tire (FC-Fast, SAS-Medium speed, SATA - Least): Moving
the most active data to costly or expensive disk (for performance) &
less active data to low cost disk. It can also use pool storage system.
CMDs:
>>”storage”>>”pool”>>R.C “Pool
0”>>”properties”>>S “Tiering” Tab.
>>Pools>>R.C
“Pool 0”>> S “Strat active”.
- CORE
EDGE: CORE Connected to
Storage.
EDGE
connected to Host.
- DMX Architecture: Front End,
Cache, Back End, Disks.
- Hyper is a Slick, One part
of physical disk.
- Selera Operating
Systems – DART
- Clariion Operating Systems – FLARE.
CMD
Line – San Copy.
GUI
– Navisphere.
- VNX Operating Systems - VNX
OE.
CMD
Line – Naviseccli.
GUI
– Unisphere.
- Symmentrix Operating Systems – Eingunity.
CMD
Line – Symcli.
GUI
– SMC (Symmentrix Management Console).
- SLA: Service level Agreement
- Fiber, GIGE, ISCON are Open
System interface.
- ESCON & FICON are
mainframe interface.
- Hardware & Microcode
(73,74,75,76)
52
– Symm4
53
– Symm5
56
– DMX 1 / 2 (5672)
57
– DMX 3 / 4 (5773)
58
– VMAX (5874, 5875, 5876)
- Diff B/W Vmax SE & Vmax:
Vmax SE Cannot Expanadable, Performance & availability.
Vmax Can Expandable, Scalability.
- Vmax has 8 Engines – each
engine has 2 directories – each directories has 128 FE ports.
Each System Bay has – 3 Stand-by-power supply
+ 1 UPS (uninterrupted power supply).
Operation
Layer:
L1: Symm based app, host-based app,
and independent app.
L2: EMC Solution Enabler API.
L3: Symm Enginuity Operating Environment.
L4: Symm hardware.
- Read
Hit: Requested data in the Global memory.
- Read
Miss: Requested data not in Global memory and retrieved from disk
Device.
- Fast
Write: The Channel directory store the data in Global Memory and
sends “Channel End” and “Device End” to the host.
- Delayed
Fast Write: Disconnect the Channel director from the channels, when
sufficient global memory space is available, then the channel director
re-connect to their channels and process the I/O request as Fast Write.
- Symm
Service Processor is used to manage IMPL.BIN File.
- Dynamic
Sparing (Spare Disk): Protection of all volumes from loss of
data.
- Local Replication: Time
finder / Clone / Snap /and mirror.
- Tiering:
Tiering is the process of grouping the disks based on their size, speed
and Technology (Tier consisting of 1TB SATA or 400GB FC 10K Disks)
- Journaling: Used
to speed up the processor.
- SCSi: used
to connect certain devices with limitation.
- Vault Disk: First
four disks in a 1st Enclosure, it contain OS
- D-Stage: when
right cmd id given, where power failure occurs.
- Clar
Alert: It is used to notify Emc people about error occurs in
system.
- Sniff
Verify: Low Priority Check.
- Back-ground
Check: High Priority Check, cannot be interrupted, manually
operated.
- SPOF: Single
point of failure.
- CMI:
Clariion message Interface
- Hot
Spare: Backup disk, When disk failure occurs
- Flushing
Right Cache: To maintain free cache pages are flushed are moved to the
right cache to the disk.
- Three types of flushing: Ideal Flushing,
Watermark
flushing,
Force
Flushing.
- User
Quota Restriction: Limiting the disks blocks for a
particular users.
- San
Copy: used to transfer vnx to 3rd party storage.
- Access
Logic: Masking & Mapping.
- ALUA:
Assessment logical unit access.
- Power Path: manage
active-passive from host side, multi pathing and load balance.
- CIFS: File
Format in windows.
NFS: Unix or
Linux.
- Quorum
Drive: It is used to store the info about which drive is active or
not used in windows.
- SMART
GRIP: It is used for all meter reading from all the applications.
- NPIV: Node
Port ID Virtualization, it is FC facility, it allows N port to connect
virtually to a single physical port.
- When power Failure occurs,
Data is moved to Vault Drive.
- Data
Duplication: If two servers are accessing came data.
- NP
Backup: taking backup into a tape drive.
- SymmWin is in
symmentrix service processor.
- Solution Enabler 7.0 and higher running on the symmentrix Vmax.
- We can run
up to 4 concurrent configuration changes session at the same time.
·
Default Stripe Size is 1920
·
What is Concatenating &
Stripped?
Concatenating - First byte of data at the
beginning of the first device and addressing continues to the end of the
first device before any data on the next device is referenced.
Stripping - divides the data to a series of
stripes.
- Once we dissolve the Meta,
we will never get that data back.
- What is the cmd to Drain the
pool cmd: rebalance.
- DR: Disaster Recovery.
IE: implementation engineer.
CE: customer Engineer.
- SHIFT + CTRL + F12: To open
engineer mode.
- VIO generates Virtual WWN.
- We can pick a least used FA
port from Performance Monitor.
- Explain
Rule 17 in DMX: The Rule of 17 is to make sure that redundancy is in place
so that the host does not lose access in case of a FA/DA director failure.
The director cage of DMX can have
16 director cards numbering from 1-16. Two director cards are paired in
such a way that the total adds up to 17. Example when a host is connected/
lun is mapped
to the FA it is mapped to directors 1 and 16 or to directors 10 and 7.
·
How do you calculate number of
cylinders for 50GB LUN?
A cylinder is roughly 1 mb in size and 0.937mb to be precise
15 tracks -1 cylinder
64 blocks – 1 track
512 bytes-1 block
1024= conversion of bytes to kb to mb to GB
GB=cylinder *15*128*512/1024/1024/1024-DMX3 DMX4 VMAX
GB=cylinder *15*64*512/1024/1024/1024 -DMX DMX2
- What is
the maximum hyper size in DMX-4?
60Gb and in case of Vmax 240Gb
- How
many hypers can create in a Single disk?
255 and in case of Vmax 512
- How
many members can contain in one Meta?
Max 255 members
- How
many LUN IDs available per port?
Technically speaking 2048. Per port pair 4096, however this is flexible
meaning either one can have all the 4096 devices or 2048 each or any
combination which does not exceed 4096. However this is not a good
practice.
- What
Dynamic LUN addressing?
Once the lun id on the port crosses 255 the host will not be able to see
the lun and hence lun offset has to be used which has to be implemented
carefully if not would lead to host losing access to devices (luns). In
order to overcome this dynamic lun addressing is used in which the luns
are numbered in the ascending order to the Host HBA
- How do
you add a new member to the existing Meta?
using the add command
symconfigure –sid 1234 –cmd “add dev X to meta Y”; commit
·
Briefly explain the DMX-4
supported Device types?
Mainframe and Open systems
devices
- What
are the DMX-4 supported disk types, no. of disks and maximum capacity?
FC, SATA. SSD supported. Capacity and number of disks vary
from configuration to configuration.
- What
are the RAID levels DMX-4 Supports?
RAID 0 - unprotected
RAID 1 - 2-way Mirror
RAID 5
RAID 6
RAID 1 / 0 - 2 way Mirror Meta (Striped).
- What is
Preview, Prepare and Commit while using Symconfigure command?
Preview - verifies the command
syntax
Prepare - ensured that
sufficient system resources are available and also checks for any existing
locks
Commit- commits the
configuration. This can be run directly as it performs both the Preview
and prepare actions as well.
·
How do you check the failed disks
in the Symmetrix Array?
symdisk -sid 2258 -failed list
- What
are the service states of a device?
RW
NR
Write_disabled
- How do
you reserve the devices?
symconfigure –sid 4042 reserve dev 0667
- How do
you check the free space by Disk group and Array as whole?
symconfigure list -freespace or more accurate is symdisk list
-dskgrp_summary
·
How many Cache directors,
Front-end directors and Back-end directors we can use in DMX-4?
Cache directors -8
Front-end directors -8
Back-end directors -8
·
What are the different types of
Front-end directors and the purpose of each one?
Mainframe CKD devices:
ESCON (EA)
FICON (EF)
Open Systems FBA
Fibre channel (FA)
ISCSI (SE)
etc
·
What are the Management Tools for
DMX?
EMC Control Center (ECC)
SMC
EMC Solutions Enabler
EMC Symmetrix Performance
Analyzer
·
What are the major components of
System Bay and Storage Bay?
System Bay:
Directors and
Memory boards, FANS, KVM, SPS, UPS, Power Supplies, XCM boards
Storage Bay
DAEs, BBU (Battery
Backup Unit), SPS, LCC Link control card
- Can
windows, Linux, Solaris share the same FA in DMX? ANS: YES
- Host is
unable to see the storage, what may be the problem?
Host WWN issue, Zoning issue,
switch port failure, connectivity issue, SAN disk issue
- What is
VCMDB and how do you take the backup?
The Symmetrix Volume Configuration Management (VCM)
database stores access configurations that are used to grant host
access to logical devices in a Symmetrix storage array. The VCM database
resides on a special system resource logical device, referred to as the
VCMDB device, on each Symmetrix storage array.
Information stored in the VCM database includes, but is not limited to:
- Host and storage World Wide Names.
- SID Lock and Volume Visibility
settings.
- Native logical device data, such
as the front-end directors and storage ports to which they are mapped Masking operations
performed on Symmetrix storage devices result in modifications to the VCM database in the Symmetrix array.
The VCM database can be backed up, restored, initialized
and activated. The Symmetrix SDM Agent
must be running in order to perform VCM database
operations (except deleting backup files).
Backup the VCM database
# symmaskdb backup
·
What are the Symmetrix Business
Continuity Tool
Time finder
SRDF
·
By using what symcli command we
can check the HBA details and physical details
symmask list hba –list local host hba details
symmask –sid 1234 –wwn wwn list logins
symmaskdb –sid 1234 –host name list capcity (not in VMAX)
·
How do you list the Hosts which
are connected to particular director port?
symamsk –sid 1234 list logins
–dir 10e –p 1
·
How do you check the total
allocated storage of a Host?
Symmaskdb –sid 1234 –host name
list capacity
·
What is the purpose of bin file
in SAPAPI database?
It contains the configuration
information for a symmetrix. The file defines the
Physical
hardware configuration:
-Directors
-Memory
-Physical
Drives
Logical
Storage configuration:
Emulation, number, size and data
protection schemes for logical volumes.
Operational
parameters and features:
Located on each director and
in SP
·
What is pre check list to assign
to storage to the host?
Host WWN details.
Host and SAN connectivity to
Fabric Switch
Type of storage needed(Tier
1,Tier2 ,Tier3 )
Size of the LUN
·
How do you check the login hosts
in the Array?
symmask –sid 1234 list logins
·
create a
zone and place it in the vsan # zone name testzone1 vsan 4
add a member (port wwn example) # member pwwn 10:00:00:00:c9:21:40:b8 (port on
the host)
add a member (fabric port wwn example) # member fwwn 10:01:10:01:10:ab:cd:ef
(port on the switch)
add a member (FCID example - hard zoning) # member fcid 0x7f0000 (24 bit
address)
add a member (FC alias example) # member fcalias payroll
·
MDS-series
common commands
display logged in WWN, display vsan information # show flogi database
display the specific vsan logins # show fcns database vsan 4
activatng a zoneset # zoneset activate name zone1 vsan 4
delete a zoneset # clear zone dataabse vsan 4
configure the default zone # zone default-zone permit vsan 4
display zones and zonsets # show zoneset active
# show zoneset
# show zoneset active vsan 4
copy active zone set to the full zone set # zone copy active-zoneset
full-zoneset vsan 4
distribute the full zoning database to others switches # zoneset distribute
full vsan 4
==============================================================================
Creating zone by WWN
#zonecreate "zone1", "20:00:00:e0:69:40:07:08 ;
50:06:04:82:b8:90:c1:8d"
Create a zone configuration #cfgcreate "test_cfg", "zone1 ;
zone2"
saving the zone configuration #cfgsave (this will save across reboots)
enable the zone configuration #cfgenable "test_cfg"
saving the zone configuration #cfgsave
view zoning information #zoneshow or cfgshow
If you want you can create alias for zone members as well with
"alicreate" and use cfgadd command to add zones to the active
configuration.
- DHCP provides the IP address to the computer.
- SYN packet – Communication Start.
- FIN packet – Communication End.
Time Finder:
allows you
to nondisruptively create and manage point-in-time copies of data. For example,
Time Finder allows you to create a point-in-time copy of critical data while
this data continues to be used in production operations.
TimeFinder
The TimeFinder
family of software provides trusted local storage replication leveraging the
high-end Symmetrix VMAX Architecture. The TimeFinder family enables IT
organizations to create local copies for DR testing/validation, backups,
point-in-time recovery, database consistency checks, and test/development. The
TimeFinder family consists of the following options:
·
TimeFinder Clone – High performance, full source copies
·
TimeFinder Snap – Economical space saving copies
·
TimeFinder VP Snap – Space-efficient snaps for VP devices
Symmetrix Remote Data Facility (SRDF)
The SRDF family of software is the gold standard for remote replication
in mission critical environments. Built for the industry-leading high-end VMAX
hardware architecture, the SRDF family of solutions is trusted for disaster
recovery and business continuity. The SRDF family offers unmatched deployment
flexibility and massive scalability to deliver a wide range of distance
replication capabilities. The SRDF family consists of the following options:
·
SRDF/S – Synchronous option for zero data exposure loss
·
SRDF/A – Asynchronous option for extended distances
·
SRDF/Star – Multi-site replication option
·
SRDF/CG – Consistency Groups for federated data sets across arrays
Migration to Symmetrix VMAX
VMAX customers have choice and flexibility for migrations in both open
systems and mainframe environments. By enabling customers to perform migrations
at the host or array level depending on their specific requirements, EMC offers
the broadest set of migration options to help customers rapidly realize the
performance and efficiency benefits of the VMAX family in the virtual data
center. The migration options to migrate to the VMAX are as follows:
·
Open Replicator for Symmetrix – Heterogeneous, open-systems array-based
migration
·
Federated Live Migration (FLM) – FLM using Open Replicator
non-disruptively migrates workloads and redirects/hosts to the VMAX
·
z/OS Migrator – Non-disruptive migration for mainframe environments at
the volume or dataset level
·
SRDF/DM – High performance Symmetrix to Symmetrix migration
·
Open Migrator – Host-based open systems data migration
Fully Automated Storage Tiering for Virtual Pools
(FAST VP)
FAST VP automatically optimizes performance in a tiered environment
reducing costs, footprint and management effort. FAST VP puts the right data in
the right place at the right time. FAST VP maximizes utilization of Flash Drive
capacity for high IOPS workloads and maximizes utilization of SATA drives for
capacity intensive applications. FAST VP is a game changing technology that
delivers automation and efficiency to the virtual data center.
Points to
Remember
- The software used to split
physical disks into volumes is called Hyper Volume Extension.
- SymmWin software is used for
modifying system configuration file (IMPL.bin).
- Symrdf -- command manages dynamic RDF operations
- symaccess -- manages masking
and mapping operations on the VMAX
- symfast and symtier -- commands are responsible for managing
FAST operations
- symmigrate -- manages
virtual LUN migration.
- specific devices are
“mapped” to specific ports by assigning a channel address. Host systems
discover and access Symmetrix devices using these Channel Addresses.
