The following message is a courtesy copy of an article that has been posted to bit.listserv.ibm-main,alt.folklore.computers as well.
[email protected] (McKown, John) writes: > This just occurred to me. I wonder if I'm suffering from lack of > oxygen to the brain. But, as best as I can tell, SDSF is capable of > accessing the SPOOL files for a non-active JES2 system. At least as I > recall from the past, I did this. So I got to wondering. Suppose I > have a z/Linux system running in the same complex. Perhaps under > z/VM. It might be nice (FSVO nice), if I could logon to z/Linux and do > SDSF ad least to the extent of being able to read SPOOL files. Of > course, being a bit paranoid, I would only allow a READONLY access to > the DASD containing the SPOOL data. And there is always the specter of > security. There may be SPOOL files which I should not be able to even > READ (like payroll or HIPAA reports or ...). So this may be a stupid > idea. But the though is intriguing to me. there had been significant enhancement of cms os/simulation ... including handling pretty much all (both r/o and r/w) os formated disks & files (the cms os/simulation had been less than 64kbytes of code ... but there were comments that it was really cost-effective compared to the size of the MVS os/simulation). However, this was before the shutdown of the vm370 group and their move to POK to support mvs/xa development (person left the company and remained in the boston area) ... and the enhancements appeared to evaporate. A couple years later I was getting heavily involved in redoing assembler implementations in more appropriate languages ... recent reference to doing DUMPRX in rexx http://www.garlic.com/~lynn/2010e.html#10 Need tool to zap core I also redid a spool file system implementation in pascal running in virtual machine. The los gatos lab had done the original mainframe pascal implementation for vlsi tool implementation ... that pascal went thru several product releases started with IUP before evolving into program product. That pascal was also used to implement the original mainframe tcp/ip product (and suffered from none of the buffer length exploits that are common in C language implementations). recent reference to that tcp/ip implementation: http://www.garlic.com/~lynn/2010d.html#72 LPARs: More or Less? My full (spool file system) implementation moved the complete system spool file implementation into virtual address space ... however, I packaged subset of the routines as independent utilities for doing spool file diagnostic (on normal systems). It is actually relatively straight-forward activity. Total aside, part of the issue was that the internal networking technology ran thru the spool system (implemented as a service virtual machine, or "virtual appliance") ... and for various implementation reasons would only get 20kbytes-40kbytes/sec sustained thruput (before controller caches, etc). In HSDT, some past posts http://www.garlic.com/~lynn/subnetwork.html#hsdt I needed multi-megabyte sustained thruput ... so was having to add all sorts of things like lazy writes, contiguation allocation, multi-buffering, read-ahead, etc (however, lazy writes still required logged operation ... either they completed or had to be redone) ... total aside, some of this sort of thing recently shows up in enhancements for ext4 filesystem ... minor reference to google upgrading to ext4: http://arstechnica.com/open-source/news/2010/01/google-upgrading-to-ext4-hires-former-linux-foundation-cto.ars HSDT was also having some vendors, on the other side of the pacific, build some hardware. The friday afternoon before a vendor visit trip, the communicationg group distributes an announcement for a new "high-speed" discussion group in an internal forum ... with the following definitions: low-speed <9.6kbits medium-speed 19.2kbits high-speed 56kbits very high-speed 1.5mbits monday morning in vendor conference room on the other side of the pacific: low-speed <20mbits medium-speed 100mbits high-speed 200-300mbits very high-speed >600mbits -- 42yrs virtualization experience (since Jan68), online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
