horace_ng
Contributor
Contributor

VDP backup performance over NBD

I got a backup bottleneck on VDP over NBD on a 1Gbps link. The backup is capped at 20MB/s very steadily, but if I start a cold VM migration between those two hosts (same source and destination) at the same time, it can still pump up to 110MB/s, i.e. definitely not CPU/IO/NETWORK bottlenecks. As I search through internet, someone suggested that there is a upper limit on the traffic at the management interface. I would like to know if I can lift the limitation, so that I can backup my single 3TB VM successfully within 24 hrs.

By the way, backup job will be forced to cancel after exactly 24 hrs? Anything can do about it?

2013-08-21 10:44:09 avvcbimage Info <16037>: Cancelled by MCS

2013-08-21 10:44:09 avvcbimage Info <0000>: Starting graceful (staged) termination, MCS cancel (wrap-up stage)

2013-08-21 10:44:09 avvcbimage Info <16022>: Cancel detected(externally cancelled by Administrator), terminated(1).

2013-08-21 10:44:09 avvcbimage Info <16022>: Cancel detected(externally cancelled by Administrator), terminated(1).

2013-08-21 10:44:09 avvcbimage Info <9746>: bytes submitted was 2064249651200

2013-08-21 10:44:09 avvcbimage Info <0000>: pax_container::endfile(virtdisk-flat.vmdk,2064249651200) returned problem:24

2013-08-21 10:44:09 avvcbimage Info <0000>: pax_container::enddir returned problem:24

2013-08-21 10:44:09 avvcbimage Info <16022>: Cancel detected(externally cancelled by Administrator), terminated(1).

2013-08-21 10:44:11 avvcbimage Info <6688>: Process 31737 (/usr/local/avamarclient/bin/avtar) finished (code 163: externally cancelled)

2013-08-21 10:44:11 avvcbimage Warning <6690>: CTL workorder "XXXXXXXXXXXXXXXXX-1376966624139" non-zero exit status 'code 163: externally cancelled'

2013-08-21 10:44:15 avvcbimage Error <9768>: Avtar exited with 'code 163: externally cancelled'

2013-08-21 10:44:15 avvcbimage Info <16038>: Final summary, cancelled/aborted 2, snapview 4, exitcode 169: externally cancelled by Administrator

2 Replies
schepp
Leadership
Leadership

Hi,

I did a little research, as I'm also suffering form the 20MB/s max transfer rate when taking backups of VMs on remote Hosts.

Only thing I could find was this in the documentation center: VMware vSphere 5.1

It says there are NFC Session Connection Limits:

Limited by a transfer buffer for all NFC connections, enforced by the host; the sum of all NFC connection buffers to an ESXi host cannot exceed 32MB.

52 connections through vCenter Server, including the above per-host limit.

Regards

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horace_ng
Contributor
Contributor

Didn't say anything about speed. I don't think the limit of NFC connection and the 32MB buffer will cap a single VM backup at 20MB/s.

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