> -----Original Message----- > From: The IBM z/VM Operating System > [mailto:[EMAIL PROTECTED] On Behalf Of Dusha, Cecelia > Ms. WHS/ITMD > Sent: Wednesday, May 17, 2006 5:25 AM > To: IBMVM@LISTSERV.UARK.EDU > Subject: 3390 Huge Volumes > > > The 3390 mod 9 are not large enough for the customer's application. > > What is the largest volume z/VM 5.1 can handle? If only the > data utilized > the one huge volume, what would be the repercussions? > > Please advice. > > Cecelia Dusha >
IIRC, currently the largest 3390 emulation is one with just a bit less than 64K cylinders. I think that this is about 57 Gb in size. This is an absolute upper limit to the 3390 architecture because the cylinder number is an unsigned half-word. Now, I would ask some futher question. First is, what OS is the application running under? Eg: CMS, z/OS, z/VSE, z/TPF, or z/Linux? In all cases other than CMS, the application should be able to use multiple volumes for its data. In z/Linux, you can create really huge filesystems by using LVM to create large logical volumes which are spread over multiple physical 3390s. So, personally, I'd ask the customer why a "really huge" single volume is required. There may be a "better way" than just creating a single super huge 3390. Also, remind them that disaster recovery is complicated by using non standard volume sizes. Also, it is usually much faster, for example, to restore 3 x 3390-3 volumes than 1 x 3390-9 because with the 3390-3, you can restore all three concurrently. The larger the physical 3390 volume, the more time it will take to restore it in a disaster (either remotely or locally!). -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited.
