LTO4 Tape size is not correct

[great_vc]

Hi,

We have an HP MSL G3 Tape Library. This is working for over 5 years with the tapes below.



I know that the 1.6TB with asterisk means that is after hardware compression. On VERITAS NETBACKUP before we made the switch to VEEAM i got about 1.3TB on each tape valid written data.

On Veeam i get the actual uncompressed size. I have check on some point the hardware compression on the Tapes pool in VEEAM i don't know if that is enough. Do i need to change any other setting ? How can i get the full 1.3TB on my tapes ?



Many thanks

[Mildur]

Looks normal to me.
For LTO4, that‘s the physical capacity. Veeam shows you the physical capacity in that screen and not the 1.6TB with compression.

Veeam Backups Restore Points, which you write to tape are already compressed. 800GB worth of veeam backup files on the tape could be between 800GB and 1.6 TB actual uncompressed data, if you restore the entire content from the tape. It depends on your data type before the backup how good the compression will be.

[great_vc]

Hi Midlur and thanks for the reply.

So if i understand this right VEEAM does not display the data in compressed mode only the uncompressed one in the information box. So here that we see the free capacity



it is not actually 29.7GΒ , this is without compression.

So if i restore everything from that tape then the resulted restored GBs will be ~1.4TB correct ?

I'm asking cause for the first time in 5 years, (even previous month with NETBACKUP) i always had 2 tapes used and the second was never full, now we are at 22 of the month (change tapes every 8th of next month so more backups are coming) and it is asking for a new tape. I have to move a new tape to continue the backup.
That is what frightens me most.

[Mildur]

Your welcome, Vassilis.

So if i understand this right VEEAM does not display the data in compressed mode only the uncompressed one in the information box.

That's correct.

So here that we see the free capacity it is not actually 29.7GΒ , this is without compression.
So if i restore everything from that tape then the resulted restored GBs will be ~1.4TB correct ?

That depends on the type of data. Not every data type has the same compression efficiency after the backup.
You can check this in the backup properties in the veeam console:
Veeam Guide - Viewing Properties

I'm asking cause for the first time in 5 years, (even previous month with NETBACKUP) i always had 2 tapes used and the second was never full, now we are at 22 of the month (change tapes every 8th of next month so more backups are coming) and it is asking for a new tape.

I'm sorry, I don't know about NetBackup. Never used it.
Can you tell us more about what job you have configured in Veeam?
- File to Tape Job?
- Backup to Tape Job?

If I get your configuration correctly, you are using an entire month the same media set to store backups on the the tapes. Are this tapes used for protection against ransomware? If yes, you should consider rotating the tapes more than once in a month. When the tape is in the drive, a hacker can remove the data from the tape and you have no current backups.

If you change the tapes only once in a month, is it possible, that you have multiple full backups on the same tape (media set)? Multiple Full Backups on a single tape could lead to much more tape space required.

My recommendation for Tape Backups:
Use GFS Media Pools with Backup to Tape Jobs. Normally, I use LTO 7 or LTO 8 for our SMB Companies.
Each Tape contains a fullbackup.
- 4 Tapes for weekly GFS (weekly rotation)
- 12 Tapes for monthly GFS, if archiving is needed (monthly rotation)
- 10 Tapes for yearly GFS, if archiving is needed (yearly rotation)