Nathan Phan writes: > > > > The course emphasized extensively on the placement of > > each logical > > volume's PP i.e. the above physical partitioning > > (1016) layout...either > > on the outer edge, middle or inner edge of the > > cylinderical disk. > > They allow you to specify where to place the PP, this is because > accessing to different location on the disk plate give you different > speed. I think accessing the outer edgeis the fastest, I can't > remember exactly. It allow you to place your most frequent access > data on the fast location. But this may not be applicable any more > because the disk technology had improved over the years. In older > day, it make sence because you don't have many disks in a system, > typically people buy one big disk can cut it out for different > usages. Nowaday, people prefer many smaller disks to make up a pool, > especially for database access.
Actually, that's a feature of LPs, not PPs. When you create a logical volume (LV), you can specify where you'd prefer to have LPs allocated for that LV -- inner edge, inner middle, center, outer middle, or outer edge of the corresponding PV. At least among the folks I've talked to, it's an -funroll-loops level of control, and most just take the default (outer middle) policy. (Outer is indeed supposed to be faster as bit rates can be higher there, and contiguous is better. But whether tweaking such a thing makes a useful bit of difference is a different matter ...) -- James Carlson, KISS Network <[EMAIL PROTECTED]> Sun Microsystems / 1 Network Drive 71.232W Vox +1 781 442 2084 MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677 _______________________________________________ opensolaris-discuss mailing list [email protected]
