Gustav Brock
Gustav at cactus.dk
Fri Feb 8 11:30:29 CST 2008
Hi John Perhaps the drives or the controller can be set for (individual) delayed spin-up? That could be done for SCSI drives. Not sure about IDE drives. /gustav >>> jwcolby at colbyconsulting.com 08-02-2008 18:21 >>> I am trying to copy a 30 gig file from one computer to another. Task Manager shows it "bursting" transmission at 30-40% of network bandwidth for 10 or 20 seconds and then transferring at 3% or so for 10 minutes or so. While it is bursting it shows "will complete in 10 minutes", when it trails off it shows "will complete in 160 minutes". Obviously I want this thing to finish so I can copy the next file. Any idea why I would be seeing something like this? Actually I just took a bathroom break and while thinking about it I may have come up with the answer. Software raid 0. The destination disk is a software raid 0 drive using three different drives. Perhaps the destination computer is caching a bunch of data and then runs out of room to cache more while it writes the data out to the Raid1 volume. Which would answer the question of why I would choose JBOD over RAID0. The write calculations required to do RAID0. On a related note, I decided to test this theory. I shut off the computer and started fiddling with the drives. I decided to just move the drives out of my WHS box and place them in my SQL Server box and ran square up against my power supply. I have a 700 watt supply in there but when I added the three drives into that box the system would turn on, then right back off. When I disconnected the new drives the computer turned on just fine. These are old western digital caviar 250 gig drives, the kind that came out when the SATA drives were just entering the market, with a normal power connector and a SATA connector. Anyway, my 700 watt supply just wouldn't handle the load. Sigh. I now have 4 of these old WD drives just sitting there. A terabyte of identical drives and no home for them. I guess I will tear open one of my other boxes and see if I can get them mounted in some other system. John W. Colby Colby Consulting www.ColbyConsulting.com