Vitaly, this occurs on the vCenter server itself, which is on it's own hardware. Dell R610 2x15k RPM 140G SAS drives mirrored, 48G RAM, running Server 2008R2 U1. We only have 3 hosts, with 40 or so VMs.
I don't think there should be any issue with database performance, but we keep getting these in the vCenter log.
The errors are all "SQL execution took too long" including INSERT INTO VPX_BINARY_DATA and DELETE FROM VPX_BINARY_DATA", as well as multiple rule_ tables. This is on the included mssql 2008 r2 packaged database from the vCenter install.
I've cleaned the database and shrunk it, but the errors persist. I'm opening a ticket with VMware.