On Tuesday 17 November 2009 15:37:24 Todd Denniston wrote: > Benjamin Smith wrote, On 11/17/2009 01:46 PM: > > See comments below... > > > > On Tuesday 17 November 2009 07:52:01 Todd Denniston wrote: > >> Benjamin Smith wrote, On 11/16/2009 10:56 PM: > >>> I have a 1TB USB drive plugged into a USB2 port that I use to back up > >>> the production drives (which are SCSI). It's working fine, but while > >>> doing backups (hourly) the load average on the server shoots up from > >>> the normal 0.5 - 1.5 or so up to a high between 10 and 30. Strangely, > >>> even though the "load is high" the server is completely responsive, > >>> even the USB drives being accessed are! > >>> > >>> Using top to diagnose, nothing seems to be particularly high! IoWait > >>> seems reasonable (10-30%) and CPUs are 0.5%, Idle is 70-90%. Even > >>> accessing the USB partition while the load is "high" is responsive! > > you might add another field to top while you are watching, Last used cpu > (SMP), i.e., start top > press f > press j > press enter > > this should let you see if your process is bouncing between processors. The process pg_dump is "adhering" fine to processor 1. I see usb-storage bouncing between processors - I've seen it on 3, 4, 7 over perhaps a minute. What could you recommend next? -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.