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Data compression again

Maurice Reed
Advisor

Data compression again

I have just installed a DAT 40 drive and am using Veritas BackupExec 7.3 Can anyone tell me whether it is best to opt for hardware OR software compression in the back up software? While I didn't really expect to get 40Gb on a single tape I was annoyed when it filled a tape at 25.5gb. The annoying thing is that the server contents comes to 26.9gb so I would like to get it all on one tape so that it can run overnight.

Thanks
I hate bl**dy computers!!!
4 REPLIES
Marino Meloni_1
Honored Contributor

Re: Data compression again


hi

the best is hardware conpression, the software have to manage the dat to enable hardware compression, if you perform a software compression on a dat with hardware compression enable you will work like compression a zip file and you will add information to your files so that your data will encrease.
note also tht a dat 40 have a native capacity of 20 gb and with a ratio of 1/2 you can reach 40 gb, obviusly, your data have to be able to be compressed.
you can test the compression ratio of your data compressing them with winzip and see the result.
Last thing, be sure that you have a permanent streaming of your data or you will lost space on the tape
bye

marino
Maurice Reed
Advisor

Re: Data compression again

OK thanks for that. Very little of the data being backed is compressed(ZIP files etc) much of it is Word docs which normally compress well. You say to ensure a constant stream of data. The backup is scheduled to run during the night when no users or other work running.
I hate bl**dy computers!!!
Sanjay_6
Honored Contributor

Re: Data compression again

Hi Maurice,

The normal suggestion would be to use software compression. Not hardware. Use the compression from the backup executive. Do not enable any hardware compression on the Drive. You should get better

Thanks


Marino Meloni_1
Honored Contributor

Re: Data compression again

hi
what i meen with hardware compression, is to enable it (hardware compression) from the software (usualy you have to check a flag), the process of compression, will be performed by the hardware (the bios have a routine wicht do the same thing that winzip) in this way your server is more free than conpressing itself the data before sending them to the dat (!!note that the compression process only delete the blank spaces in the middle of the data).
About streaming data, this can be an issue if you are backing up data througt the lan, or with progarmms running on the server, if the data are localy and nobody work on the server, no problem the flow of data will be constant

For Sanjay, let me know if something is wrong

bye

marino