08-18-2014 12:30 AM
Hello everyone
Sorry if i am asking this question again.
i have an lt0-5 cartridge of 3tb on my tape device.
backup exec 2014 see's the cartridge as 1.5tb on 2 partition, what i mean is that. on backup exec, i see 1.5tb and 1.5tb.
i understand that the native capacity of an lt0-5 is 1.5tb.
what i need to know is backing up to both 1.5tb is this ok?
i manually insert the barcode for both partitions. my second question is if i decide to use barcode label on the cartridge will backup exec see it as 3tb or 1.5tb and 1.5tb
Solved! Go to Solution.
08-18-2014 01:09 AM
LTO5 is 1.5TB native (1:1 compression!) and 3TB compressed (2:1)...read below:
http://en.wikipedia.org/wiki/Linear_Tape-Open
Never go according to the compressed size of the tape.
1.3TB on a 1.5TB tape means you're either not backing up enough data, backing up data that is compressing to less than 1.5TB, or backing up data that is getting less compression (ie. 0.9:1 if you are perhaps backing up compressed data that is increasing in size).
Check the compression on the tape...this will tell you what you are getting.
Thanks!
08-18-2014 08:28 AM
08-18-2014 12:40 AM
Hi,
1.5TB is the native 1:1 capacity, so this is correct. Backup exec is seeing the correct size of the tape. 3TB is 2:1 compression which you're not likely to get in the real world to be honest. A good compression ratio is between 1.2:1 and sometimes up to 1.6:1.
Backup Exec is reporting correctly, and putting barcode labels on won't see the 3TB size...it helps with management of tapes.
Thanks!
08-18-2014 12:51 AM
Thanks
please look at the image below.
i inserted an lt0-5 cartridge of 3tb onto my tape device.
the size that i saw was 2.78tb
the slots tho, are 1.3tb and 1.3tb
08-18-2014 01:09 AM
08-18-2014 01:09 AM
LTO5 is 1.5TB native (1:1 compression!) and 3TB compressed (2:1)...read below:
http://en.wikipedia.org/wiki/Linear_Tape-Open
Never go according to the compressed size of the tape.
1.3TB on a 1.5TB tape means you're either not backing up enough data, backing up data that is compressing to less than 1.5TB, or backing up data that is getting less compression (ie. 0.9:1 if you are perhaps backing up compressed data that is increasing in size).
Check the compression on the tape...this will tell you what you are getting.
Thanks!
08-18-2014 01:15 AM
hello pkh
yes i have 2 tapes in the library. u might be correct to say thats why i see 2.78tb
but what about the 4.17tb?
the backup job is set to keep the data for four weeks. does this mean that after 4 weeks it will be overwritten?
08-18-2014 01:24 AM
...yes they will be overwritten/appendable after 4 weeks.
Thanks!
08-18-2014 01:34 AM
08-18-2014 01:52 AM
hello pkh.
i only have two tapes. the 1 offline is actually inside the device. i haven't been able to bring it back online.
let me explain.
i had just one tape before. backuped up data into it. for some reasons it didnt come back online
i inserted a new tape into the device. making it two tapes now.
the new one shows up as 2.7tb
where the 4.17tb is coming from i dont know
i am about to pay for the symantec license and need to be sure of this
08-18-2014 08:28 AM