Client, I’m 99% sure.
I’m currently running an incremental image backup. There is almost no traffic between the client and the server, I can tcpdump the stream and keep track of it. It’s mostly keep-alives.
The client keeps running at 3.something MB/sec, also if I change the priority to Realtime and the I/O Priority to High.
I tried Windows Server Backup, btw. To see if that is just as slow with VSS, but that kicks at around 80MB/sc.
That can be normal. It reads the whole disk and sends only changed blocks.
I understand that. But if the server would be a bottleneck, one would expect a lot of traffic between the client and the server. The server is idle…
I am currently waiting for the Windows 8.1 ISO to come in and see if that behaves the same.
The question is if it is the bottleneck during full image backups
Well. I’m seeing the exact same disk-read-speed on the client in an incremental run and in a full backup. So don’t you agree that we can pretty safely assume that it’s the client?
Yeah, my guess is that the read-ahead needs improvement. I just need to make sure that’s the bottleneck and that it is not simply fixed by increasing the CPU priority of the read-ahead thread.
(The normal Windows task manager can’t set thread priorities, Process Hacker 2 can)
Windows 8.1 has about the same performance…
@uroni If I need to test anything, please let me know. My client is in quite a hurry, as one of his back-ups currently takes more than 24 hours.
Thanks for the investigation. I have an idea on how to improve it but it would be a pretty large change and as such suitable for 2.1 which will be a while (a month or something).
Hmm. Any way to speed this up? I have just bought a few licenses for CBT, so that should help for incrementals, right? But my customer is really anctious to get this right…
Yes should help, but then you probably already tested that. Most of the time will be spent testing the new versions, so you could watch the testing category and use early beta versions.
Does the phrase “Improved image backup performance” in the UrBackup Server 2.1.0 beta/Client 2.1.0 beta have anything to do with this thread?
Yes. Hope it is improved in your case as well.
I upgraded to 2.1.18 and client 2.1.14-cbt. Image backups are even slower now at about 15Mbit (so about 1MB/sec)…
If you run iotop or iostat on the server while the backups are running, what do you see?
This is not a server issue, it’s about idle.
Does it have the same speed if you run a full image backup?
