This article is compiled from the EMC Japanese Forum Event -Ask the Expert "Data Domain Anything you can ask".

The original address: https://community.emc.com/thread/194000.

Summary thread (IN JP): https://community.emc.com/message/818592#818592.

Ask the Expert Summary: ALL you can AsK ! Data Domain

Introduction

Not only Enterprise customer can use Data Domain but also SMB has demand for this product. This thread is for you to quick understand Data Domain and high lights of this event!

Detailed Information

Question 1:

What is Vendor Support stands for?

Answer:This is function to create alert mail and create daily auto support log sent out to EMC.

(Alert mail/log will be sent to autosupport@autosupport.emc.com if there is a contract with EMC)

How to get Autosupport

Question 2:

What kind of issue will create ``Auto call (Call Home/Dial Home) `` cases?

Answer:

Most of the Hardware issue would create Auto Call cases. See below for detail.

DDR 5.4.1-411752 message Catalog

Question 3:

What is the Supported version for DDOS at the moment ?

Answer:

3Versions are supported currently. Which are 5.4、5.2、5.1 are the current supported versions.

Waiting for 5.5 to be GA (June 2014)

DD OS Software Versions

Question 4:

How to set SNMP Trap when File System usage go over 80%?

Answer:

There is default setting for SNMP when File System usage become 90 % 95% 100 %,but not with 80% .if you want to set as 80% , need to enable config.ems.space.extra_alerts key ...

-> HOW TO enable key? Follow below command ...

sysadmin# regshow config.ems.space.extra_alerts

config.ems.space.extra_alerts = false

sysadmin# regset config.ems.space.extra_alerts = true

sysadmin# regshow config.ems.space.extra_alerts

config.ems.space.extra_alerts = true

Ref links

How to Change Space Full Alert Message Levels

https://support.emc.com/docu50994_Data-Domain-Operating-System-Administration-Guide-5.4.pdf（MIB is in the DD already ）

Question 5:

What is the Multi tenancy and what is this for?

Answer:

Multi tenancy provides data isolation by tenant and keeps secure by tenant.

Multi tenancy provides setting up for alert by tenant. Latest version5.5 (not yet to be GA) will have additional user account

``tenant-admin ``this function call Secure multi tenant (SMT)

Question 6:

Compatibility for  DataDomain and backup server .

Answer:

As long as Backup Server has CIFS availability then it is compatible with Data Domain. But it is up to backup software that if CIFS can be used in NDMP environment.

Question 7:

Difference between GUI and CLI upon replication setup.

Answer:

GUI →"Create Pair.(This could be done from either side and affect both (Destination / Source )

CLI→Need to issue command from each side ( Destination AND Source)

Question 8:

How to set after ``Replication add``? How to change connection to host and Port?

Answer:

Issue below command (Note that you need to complete setting for ``net hosts `` on Both Data Domain)

#replication modify connection-host [port ] 　

Question 9:

Is there any impact by difference of barcode-length in DDOS 5.5?

Answer:

Barcode-length is used for inform initiator/client therefore no affect on data-flow .

( From Cmd ref ...)

barcode-length

Allows you to explicitly set the length – to either 6 or 8 – of the tape barcode that the library will report to the initiator/client.

By default (when barcode-length is not set), the library reports the length of the barcode depending on the type of library. For example, if tape AAA001L3 is put in an L180, DDVTL, or RESTORER-L180 library, the library will report this tape to the initiator/client as AAA001. If the same tape is placed in a TS3500, I2000, or I6000 library, the library will report this tape to the initiator/client as AAA001L3. However, if you do specify the barcode-length, for example, vtl option set barcode-length 6 vtl my_ts3500_library on a TS3500 library, then the barcode will be reported to the initiator/client as AAA001, which is the same length as for an L180 library.

Question 10:

What is vShpere data protection advanced and Data Domain Compatibility?

Answer:

There are supported DDOS in VDP5.5.5 Admin Guide. DD5.4 is supported.

Data Domain side supports teams is now checking latest information.

Question 11:

What is CIFS show config output shown for?

Answer:

# cifs show config　→be able to check 2 DCs

Mode                Active-Directory

Realm              

Domain Controllers       

                                      

#cifs troubleshooting domain info cmdonly show First DC IP

Question 12:

What is Garbage Collection in Data Domain?

Answer:

This is Cleaning operation in Data Domain, called GC (Garbage Collection) or file system cleaning、Filesystem Clean. This is re-cycling function for space by cleaning up deleted files so that space can be used again

(Not recommended to run this while backup is running)

Question 13:

What is the DDOS5.5.0.4/DD2200 vaulting function for?

Answer:

Vaulting is using designated area in HDD. The Data has protected with PRAM (RAM implementation) System show nvram can check status.

Question 14:

DDOS5.5.0.4 related question > Synthetic Backup-Aware Replication function is only available with DDOS5.5+DDBoost3.0?

Answer:

As long as has DDOS 5.5, it will have same function.

Question 15:

What will happen if stream over system comes in DDOS 5.5?

Answer:

Stream Quota Management (Soft Quota) will be introducing in DDOS 5.5 .ETA 173057 is fixed in 5.4.0.8 or over.

Question 16:

DDOS5.5.0.4 related question > what is VTL Configuration Backup and Restore Utility?

Answer:

ICmd intorduced in DDOS5.5 <vtl config export><vtl config import>.Those cmds are able to backup/restore files to group/vtl/initiator/option/ddvar/etc/vtl_configuration_files/ has got setting (need to delete setting for VTL / group before)

Question 17:

DDOS5.5.0.4 related question> When to use persistent-reservation in scsi target?

Answer:

Persistent reservation let assign tape drive for specific host

persistent -reservation is controlled by backup software .

Question 18:

DDOS5.5.0.4 related question > How to check CPLD/BBU, also how to upgrade?

Answer:

To check,Issue  cmd  # enclosure show   all　or Autosupportlog

Question 19:

What is ``A faulty power supply module must be replaced within 24 hours.`` means ,

Answer:

It does not have to be exact 24h. but need to be quick

Question 20:

DataDomain　OS 5.4  relatedquesiton >  How to set SNMP trap ?

Answer:

Check Data Domain mail alert 【DDOS 5.2, 5.4 】　　
Note ：Prior to 5.4 RO community need to be registered on Local host for mail trap .

Question 21:

About VRAM battery?

Answer:

Empty battery will be filled up in 3hours

To check status: system show nvram (but this is not a historical data)

If the battery has 70%or 80% charged, it will get you the status.

Question 22:

What is the impact of HW replacement and failure?

Answer:

See below

Comportment	SP	DIMM Memory	FAN	BackupBatteryUnit/NVRAM(BBU)	I/O MOdule (IOM)	SAS Cable	Power Supply(PS)	Storage shelf	DISK
Impact to system	May stop Storage . Also it may cause Power down for recovery	Possibly, FS may become disable -> system down .	No impact May cause temperature rise .	FS may be disabled so cannot take I/O from host	Using NIC for redundancy … -> may cause shot time connection loss . if there is only one NIC .. Services will be down .	the issue only for SAS cable . There is no system impact	NO impact	storage may stopped May need to power down  depends on the situation . (there issue with Power socket withing the shelf /disk/controller are not impacting system )	No impact on service
DD2500	Off Line	Off line	Off line	off line	off line	On line	On line	Off line	On line
DD4500	Off Line	Off line	Off line	off line	off line	On line	On line	off line	On line