some hardware solutions.... change PSU change hard disk to solid state disks (OCZ is fast, energy saver, with high MTBF, a very good disk is OCZ VERTEX 2, REVODRIVE (pci-express) and OCZ AGILITY 2, check read random 4kb >=200 MB/s is better than any SAS disk... latency is <0.1ms) maybe changing to solid state is a good solution (cost is the point here) another point is when startup remove (hot plug) some disks, and plug after 2011/2/1 Stan Hoeppner <stan@xxxxxxxxxxxxxxxxx>: > John Robinson put forth on 2/1/2011 7:10 AM: > >> That'd be an excessive amount of time to wait. A quarter of a second is more >> than enough, a tenth of a second would probably be enough. It's just the motor >> inrush current you're trying to avoid having simultaneously. > > The blowers in a typical 2U server chassis will have slightly more startup > current draw than the drives, assuming 5 80mm blowers and 8 2.5" drives. Mobos > don't do staggered startup of blowers. Thus, staggering the drive spin up is > pointless. Add to that the fact that most server chassis ship with PSUs large > enough to carry the current draw of anything/everything you can stuff into them. > >> So waiting another second for your array to wake up would mean you could use a >> sensibly-sized PSU operating in its 80%+ efficiency range, rather than a huge >> PSU operating inefficiently. > > A typical 2.5" 10K RPM 600GB enterprise HDD, such as the Seagate Savvio, has a > startup draw of 24.1 watts combined from the 12v and 5v rails. A RAID/JBOD > chassis of 24 such drives, which is sold by dozens of vendors today, will draw > only 578.4 watts with all drives spinning up concurrently. Most such chassis on > the market today are sold with 800w to 1800w redundant PSUs, again, making > staggered spin up moot. > > -- > Stan > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- Roberto Spadim Spadim Technology / SPAEmpresarial -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
