Windows 2016 & Dell Tape device TL2000 compression?

[rosmith42]

I am seeking verification of information.

Installed Veeam 9.5 with patch 1 on a new Windows 2016 server and migrated the database over to the server without a problem.
However, we decided to connect the Dell tape device TL2000 via SAS HBA and Windows detected and installed the driver. (Tape Device seen as "LTO tape device" in device manager and Medium changer devices is seen as "Unknown Medium Changer")
Added the tape device in Veeam and was able to create new media pools and run a tape full back up job without an issue. However, since we are using LTO6 2.5 TB/6.0 TB with compression, the job copied to tape 4.3 TBs which took two tapes instead of 1. It is my understanding that Dell TL2000 uses hardware compression to compress data to tape and yet it filled 2 tapes. Should I be using veeam software compression or should Dell tape drivers be used? I have yet to see any supported Dell tape drivers for Windows 2016.
Is there anyone else who has a similar setup in their environment?

[DaveWatkins]

Two things

First, download the proper drivers from dell and run the setup utility (don't manually install from the INF). That will install the full drivers for the changer and the tape drive(s) and stop it reporting "Unknown Medium Changer"
https://downloads.dell.com/FOLDER038852 ... 15_ZPE.exe

Second, Veeam already compresses the backup files. The hardware compression of the tape drive can't compress it anymore as it's already compressed so you're only going to get 2.5TB per tape. You can tell Veeam not to use compression but then your backups on disk will take up much more space. There are older posts that suggest Veeam's compression is significant;y better than what the hardware compression on your tape drive can do.

[Mike Resseler]

Hi Rob,

Dave is right about the drivers. Make sure the device is known in Windows Server 2016 and not seen as an "Unknown..." No matter if it is the tape device or the medium changer. I am not sure if Dell has already a driver for windows server 2016 (I can't check if @Dave's is the good one) but make sure you do that first.

For 2: Dave is correct again, but it might be that you are not using Veeam compression, in that case the hardware compression does make sense. But I don't see that a lot to be honest

[rosmith42]

Thanks for your input and suggestions.

I was reading about installing exclusive vs. non-exclusive drivers. The Dell tape device is currently partitioned into two. One drive (2) is used by networker and the 2nd tape drive (1) is used by Veeam. So am I to conclude that I should be installing the non-exclusive dell drivers? In addition, the install.readme.txt doesn't explain what "install_nonexclusive_dpf.exe" or "install_nonexclusive_no_dpf.exe" is used for specifically. Would you happen to know? Also, do you guys also use Windows 2016 with this type of Dell tape device without any issues?

[DaveWatkins]

The drivers are for 2012R2, but I've been using them successfully on 2016 for a couple of months now so they do work.

DPF in the file name is for data protection feature and from my understanding, it was if you had that feature licensed. From memory it's to use dual paths to each drive and basically MPIO to each drive. If you had it you'd know and it'd be listed as licensed in the admin portal for the library. I use the nonexclusive no dpf installer.

The partitioning unfortunately I've never used. I know Veeam likes to be the only program interacting with the library so not sure if that will cause issues if you have something else using it too

Dave

[Mike Resseler]

We do not support sharing a tape device, but you can use partitions.

The explanation is here: https://helpcenter.veeam.com/docs/backu ... tml?ver=95

Mike

[rosmith42]

Installed the Dell tape drivers non-exclusive TL2000TL4000_DRV_6257 (FGNVN) on our Veeam Windows 2016 server without a glitch.(Yes, 2012 dell drivers work too. Thanks Dave)
Ran a tape backup job and noticed it did not use hardware compression. Checked the webgui of the Dell tape device and found that data compression was turned off. Is this set by the software within Veeam/drivers? I checked the tape backup option settings in Veeam and found that "compression" was unchecked for "Use hardware compression when available." Will hardware compression be turned on once I run the tape job again or will I have to turn it on somehow in the Dell PowerVault TL2000 tape library? It seems to me it could be driver related but not sure.

[DaveWatkins]

As mentioned originally, Veeam's backups are already compressed, and using a better compression than the tape drives. Enabling Hardware Compression won't do anything but possibly slow down your backup as you can't compress already compressed files (in fact it grows slightly when you try).

The only reason I could see to use hardware compression is if you're backing up non compressed files to tape rather than Veeam backup files