Made some more testings. This is very interessting...
Veeam Backup Server (VBR), Proxy, Repository is the Same VM on a dedicated ESXI Host. 10Gbit NIC for Management, vMotion, VM Traffic
Client (the machine configured in the test backup) is running on the production ESXI Host. 10Gbit NIC for Management, vMotion, VM Traffic
Backup job is using NBD as Transport mode (because proxy is the VBR Server on another Host which has no access to the Storage where the Client is running on)
Test 1: Client is on the local disk (2x 300 GB SAS RAID1) on the ESXI host
01.12.2016 12:23:21 :: Using backup proxy VMware Backup Proxy for disk Festplatte 1 [nbd]
01.12.2016 12:23:22 :: Festplatte 1 (40,0 GB) 19,2 GB read at 267 MB/s [CBT]
01.12.2016 12:24:53 :: Removing VM snapshot
Test 2: Client is moved to the shared 3Par Storage (56x SAS 450GB), connected with 2x 8Gbit FC to the ESXI Host
01.12.2016 12:30:44 :: Using backup proxy VMware Backup Proxy for disk Festplatte 1 [nbd]
01.12.2016 12:30:46 :: Festplatte 1 (40,0 GB) 19,2 GB read at 74 MB/s [CBT]
01.12.2016 12:35:30 :: Removing VM snapshot
Backup from local Disk is about 3.5 times faster compared to the shared storage...
Ok now one could say the shared storage is the Limitation (maybe too much load on it), BUT why is the Performance in the following test here so much faster in hotadd mode?
Test 3: Proxy is now a virtuall appliance on the same esxi host where the client is running. client is still on the shared storage, same as in Test 2.
01.12.2016 12:38:12 :: Using backup proxy leistersrv186.leister.com for disk Festplatte 1 [hotadd]
01.12.2016 12:38:39 :: Festplatte 1 (40,0 GB) 19,2 GB read at 387 MB/s [CBT]
01.12.2016 12:39:53 :: Removing VM snapshot
At the moment i don't see why Test 2 (nbd, client on shared storage) and Test 3 (hotadd, client on shared storage) have so much different performance. if share storage would be the Problem, then i should not get 387MB/s in hotadd and only 74MB in NBD. Even if we proof in Test 1 (nbd, local disk) that nbd can be fast as well, but not when the backup source is the shared storage....
can someone explain this?