cancel
Showing results for 
Search instead for 
Did you mean: 

Backup Plan , BE 2014, Netapp NDMP

Nayabsk
Level 6
Partner Accredited

Hi All,

 

I have a 8 slot ( 7 Slots for Data & 1 Slot for Cleaning ) HP tape autoloader with single Drive and i am using LTO-6 which is 2.5TB each tape , Now i want to plan accordingly to backup 8TB weekly full backup as this needs to be tapeout every monday to offsite.

How to set compression if needed and also how to check the same. And what are all the compression ratio's supported.

 

Thanks, 

Nayab

11 REPLIES 11

VJware
Level 6
Employee Accredited Certified

Edit the backup and choose Storage on the left pane. On the right side, you can specify Hardware or Software under Compression setting.

If choosing hardware compression, the tape drive should be capable of hardware compression & should be enabled under Storage tab - right-click the tape drive - choose Details - Choose Properties.

Software compression doesn't require any other setting apart from choosing it in the backup job properties.

One of the ways to verify if compression is being used and what ratio one is achieving, then check the job log or else, check the properties of the tape media itself.

Lastly, since you mentioned NDMP, then software compression is not applicable for NDMP based backups and only hardware compression is.

Nayabsk
Level 6
Partner Accredited

Hey VJ,

Can also help me to understand the field Byte Count means ? My Job Activity monitor showing as below for a ongoing backup job which is about 8TB

 

                                                         Byte Count 

                                                           438 GB

                                                       4,195 MB/min

 

Does this mean it is transferring 438 GB/Min ?? 

 

Thanks,

Nayab

 

 

VJware
Level 6
Employee Accredited Certified

Byte count refers the amount of data which has been processed by the job. It does not necessarily mean the amount of data which has been backed up (especially in case of incremental/differential)

Nayabsk
Level 6
Partner Accredited

Also can help me to understand these fields from " When this Job Begins "

1) Overwrite media

2) Append to media ,Overwrite if no appendible media is available 

3) Append to media , terminate job if no appendible media is available 

 

How the above options works , If possible can explain with example

 

Thanks,

Nayab

Nayabsk
Level 6
Partner Accredited

I see from the tape showing compression as 1.12:1 , So if i backup 8TB of data what will be compressed size of data ?

 

Colin_Weaver
Moderator
Moderator
Employee Accredited Certified

Compression is an On or Off setting, you cannot set a ratio , basically how much compression you get depends on what you backup - files that are already compressed (MPEG4, JPG, ZIP etc) will typically not compress any further. However other file types (DOC, XLS etc) might compress more then the average. 

Typically 2:1 compression is expected over an average of file types and sizes which is why tape sizes are quoted with 2 numbers with the native capacity (lower number) being half of the compressed capacity (larger number)  There is however no guarantee you will get 2:1

VJware
Level 6
Employee Accredited Certified

This KB explains in detail about the append to media, overwrite to media settings and its effect - http://www.symantec.com/business/support/index?page=content&id=TECH5459

maurijo
Level 6
Partner Accredited

The second number is the transfer rate, in your case 4,195 MB/min.

 

438GB is the total amount of data processed, most of the times this is the same as the amount that is already backed up.

pkh
Moderator
Moderator
   VIP    Certified
I think a more typical compression ratio is from 1.2 - 1.4. A compression ratio of 2:1 is hardly achieved in real life

Nayabsk
Level 6
Partner Accredited

Ok as per my understanding If i choose 

1) Overwrite media

It will overwrite whatever media is available ?

2) Append to media ,Overwrite if no appendible media is available 

Means it will append to the available media if free space left on the tape ? or it will overwrite the same media if no space left ?

Appending means :- Adding something at the end of where last time data written to that tape 

Ex:- say if i have 10GB of data backup to tape and next job i choose to append media then it will start copying the data to tape after the end of 10GB data ?

3) Append to media , terminate job if no appendible media is available.

This job will always try to append media but if no space left on any tapes it will cancel the job ?

 

Am i right to conclude as above ?

VJware
Level 6
Employee Accredited Certified

"1) Overwrite media

It will overwrite whatever media is available ?"

Not exactly. It will choose overwritable media based on other settings such as protection level (full, partial or none), setting whether scratch media is to be used first or recyclable media etc.

"2) Append to media ,Overwrite if no appendible media is available 

Means it will append to the available media if free space left on the tape ? or it will overwrite the same media if no space left ?"

It will append to the available media if the tape is appendable and has available free space. If there is no such media, then the backup job will search for media which can be overwritten. If a backup job started and appended to a tape and if the backup requires additional tapes, the additional tapes will not be appended but overwritten.

"3) Append to media , terminate job if no appendible media is available.

This job will always try to append media but if no space left on any tapes it will cancel the job ?"

If the tape is not appendable or no space left, then yes, the backup job will be cancelled.