We are running a Windows Server 2003 r2 x64 with SQL Server 2005 (Production Server) on it. Our software provider usually access to our server to fix/update/add features to our systems (Service/Contractor Software). They were backing up the entire database (47 GB) while we were working. We experienced a very slow performance, which is not normal. They compressed the database into 6 parts (rar files) of a total of 4GB all 6 rar files on an external hard drive attached to the server. Then they were uploading them to they servers/computer for testing purposes.
They said that it might slow down the server while they were compressing the database. After the compression process finish, uploading compressed files should have little to no effect.
It is currently utilizing 0.5% of your LAN and 3% of your WAN upload bandwidth, and is uploading to us at 150KB/s (1.2Mbps). I'm doubtful this has any effect, but it is currently underway and should be done in about 3 hours.
I think his statement is not correct because in this scenario they are other factors such as memory ram, page files, I/O and transactions/connection to SQL server. SQL server is using 14 GB of 16 GB of the server's memory ram. The C drive has 27 GB free space. There are like 379 connection to SQL server.
So, my question is, is he right? I'm not 100% sure. The other thing is that it was done on a production server and in peak times.