IBM Entices Sun, HP Customers onto Linux Mainframes (eWeek) [LWN.net]

eWeek looks at IBM's efforts to move customers to Linux mainframes. "With enterprises looking to consolidate their data center infrastructures, some are turning to the mainframe platform, particularly in combination with Linux, he said. According to IBM, almost 2,800 of the 5,000 unique applications available for the System z platform are Linux-based, and Linux accounted for about half of the 1,000 or so new and updated applications created for the IBM mainframe in 2008. In addition, more than 40 percent of new System z customers in 2008 installed Linux."

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IBM Entices Sun, HP Customers onto Linux Mainframes (eWeek)

Posted May 31, 2009 1:07 UTC (Sun) by drag (subscriber, #31333) [Link]

Hrm. I only see this useful for people who are existing customers and require mainframes for other purposes then what they need Linux or Solaris or whatever for. That way they can get rid of some servers and whatnot.

Even then it's still not a easy thing to 'get'. So much mainframe software licensing is based on 'mips' and core count that having any excess capacity in CPU is a very bad thing financially. With mainframes you generally want to keep the CPU as slow as possible to reduce licensing and support costs... so if you have lots of cycles to devote to running a Linux web server or whatever then your probably doing something wrong.

Of course Linux networking capabilities are much better then the mainframe OS stuff, so that would be at least one good reason to run Linux on a mainframe. Although you can get the same benefit by connecting a Linux server to a mainframe via fiber and using that server for the TCP/IP networking side of things.

So migrating from a Unix system to a mainframe system, even if your a existing customer, only really makes lots of sense if your using Unix side of things for lots and lots of I/O and relatively little CPU. Or your using *nix systems for minor networking tasks that are not very demanding, or you want to use inexpensive Linux software in some manner to replace some of the expensive stuff you usually use the mainframe OS for and want to have very high I/O performance between the mainframe OS side and the Linux OS side.

Just my impression. I could be missing something here.

IBM Entices Sun, HP Customers onto Linux Mainframes (eWeek)

Posted May 31, 2009 12:37 UTC (Sun) by cborni (subscriber, #12949) [Link]

>Even then it's still not a easy thing to 'get'. So much mainframe
>software licensing is based on 'mips' and core count that having any
>excess capacity in CPU is a very bad thing financially. With mainframes
>you generally want to keep the CPU as slow as possible to reduce
>licensing and support costs... so if you have lots of cycles to devote to
>running a Linux web server or whatever then your probably doing something
>wrong.

IBM realized that problem as well. Thats why you can customize the
mainframe cpus either as standard engines (CPs) or speciality engines to
separate the pricing. CPs can run all mainframe OSes - and these CPs
define the CPU capacity for the software licenses of the classic operating
systems.

One speciality engine is the IFL (integrated facility for Linux). The
classic operating systems wont run on an IFL. On the other hand IFLs dont
affect the software licenses for the classic mainframe operating systems.

For example, if you have a 64 cpu system with 1 CP (running z/OS) and 63
IFLs (running Linux) the z/OS software licenses will only the consider the
one cpu.

IBM Entices Sun, HP Customers onto Linux Mainframes (eWeek)

Posted Jun 1, 2009 2:21 UTC (Mon) by drag (subscriber, #31333) [Link]

That's good to know.

The difficult thing then would be whether or not mainframe software vendors would follow IBM's lead on not counting the non-Z/OS-using mips.

IBM Entices Sun, HP Customers onto Linux Mainframes (eWeek)

Posted Jun 12, 2009 20:58 UTC (Fri) by Wol (guest, #4433) [Link]

For several years (almost since IBM introduced its linux mainframe range - last century?), the IBM mainframe customer base has been *growing*.

In other words, IBM has been getting *new* *customers* to buy their *first* mainframe. At a starting cost of about $1/4M, that's not that pricey to replace a roomful of x86 servers.

Cheers,
Wol