On 6/2/06, Alan Altmark <[EMAIL PROTECTED]> wrote:
No, you're not dreaming: it's called reserve/release. And, yes, the Linux ECKD device driver has ioctl(BIODASDRSRV) and iotcl(BIODASDRLSE). But understand that a reserve stops ALL other I/O to the device and has no effect on the caches maintained by the other hosts.
And be aware that it will only work for full pack mini disks on z/VM (or rather mini disks starting on cylinder 0). So if you break up your volume in mini disks (as John says: "partition the 3390") the reserve will not be issued by CP to the control unit, and other LPARs or CECs will not see it and it is effectively a no-op. If you want to run Linux on multiple z/VM systems that share the same DASD, I strongly recommend to look at XLINK support. This way you get the R/O vs R/W linking semantics of a single z/VM system implemented accross LPARs. It does assume you have the same CP directory on all systems so you probably would want to use DirMaint satellite support for that. When you mix and match volumes over LPARs it makes sense not to edit the directory by hand on each system anyway. PS Some installations created multiple z/VM LPARs to provide relieve for the 2G constraint with earlier z/VM releases running large Linux guests. For those installations it could be an advantage to migrate back to a single LPAR (and avoid the trouble with linking from different LPARs as well). Rob -- Rob van der Heij Velocity Software, Inc http://velocitysoftware.com/ ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
