On 19 May 2016 at 01:44, Martin Packer <martin_pac...@uk.ibm.com> wrote: > It's sort of come back to me: > > A small track size limits the virtual storage window (probably usually > below the line in 1989 when I looked at this). Or it might've been > cylinder. But I think it was track. > > I'm wondering if anyone else remembers something like this.
I'm not sure I get the "virtual storage window" idea. VIO emulates an entire disk drive in virtual storage. So where is there a window? The whole disk has to be in virtual storage at once. Well, I suppose there could be logic to not allocate Virtual until used, but that would surely better be left to VSM's and RSM's expertise at managaing their respective kinds of storage. Now maybe VIO was changed much later (surely there wasn't expanded storage in 1989...?) to use or perhaps favour expanded storage, in which case a window model could make some sense. But only if VIO was directly dealing with expanded storage rather than just requesting that RSM use it to back virtual storage used to hold the VIO disk data. Tony H. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
