Slow tape write speed 2x LTO6 + TL2000

[aaron@ARB]

Hi all,

I'll be as succinct as I can. Slow writing to tape, was previously 150mb/sec consistently, now its 50mb/sec.

VBR 9.5.4.2866

Dell R720xd, 24x 15k disks, raid 10 blah blah blah (i.e... the disk is fast enough to keep up)
Dell TL2000 library running latest firmware. Connected via 6gb/sec SAS. Veeam lists as (IBM-3573 C.30)
2x LTO6 drive sleds
Tape block size: 262144 (max listed as 1048576)
Use native commands unticked in library properties
library and drives running latest firmware (not changed since speed slowdown)

Nothing that I can tell has been installed since 4b but its really starting to impact production. Anyone with similar basic configurations? I read in another post that the fix in KB2983 fixed a speed issue, but my drive WORK fine, they are just 1/3 the speed they were previously for 'some reason'.

I'll open a case, but does anyone have any pointers? I need this working again as its snowballing a ton of other problems.

Cheers,
Aaron

[aaron@ARB]

Case # 03913070

The job(s) are reporting about the same sort of thing.

As a reminder we are talking about local storage -> SAS Tape library

16/12/2019 9:11:46 AM :: Load: Source 5% > Proxy 7% > Network 6% > Target 99%
15/12/2019 5:41:55 PM :: Load: Source 7% > Proxy 8% > Network 4% > Target 99%

All the jobs are indicative of the above whereas when it was working okay
Then for a job that was working at processing @ 141mb/sec

5/12/2019 11:28:19 PM :: Load: Source 38% > Proxy 19% > Network 21% > Target 98%