As far as I know, EDEV -FBA emulation- uses much more CPU. At the other hand, with EDEV VM's minidisk cache becomes available, what can help Linuxes with shared minidisks. And there are differences in error recovery for the paths: -if I remember well- Linux does it better than CP.
2008/2/19, Dave Jones <[EMAIL PROTECTED]>: > Given that performance is very nearly the same between SAN and EDEV > connections, or acceptably so, then I would recommend that you go with > the EDEV approach. Just have your SAN folks carve out a big chunk of SAN > storage for your use, and then allocate EDEV (FBA type) disk storage for > guests as needed from that large pool. You want to minimize your > contacts with the SAN folks, I think. > > Good luck. > > Richard Troth wrote: > > I should post this to the Linux list also, but I'll start with the VM list. > > > > On a VM system hosting Linux guests, > > I can think of one or two reasons why one might > > want to use EDEV instead of direct SAN connections. > > There are also some reasons why one would NOT want to. > > Can any of you think of reasons you would go one way or the other? > > > > Given a Linux guest on z/VM using SAN, > > should it go direct or go via EDEV? If direct, why? If EDEV, why? > > > > Thanks. > > > > I hope to add a slide to my SHARE pitch on this topic. > > > > > > -- R; <>< > > > > -- > DJ > > V/Soft > z/VM and mainframe Linux expertise, training, > consulting, and software development > www.vsoft-software.com > -- Kris Buelens, IBM Belgium, VM customer support
