Don't discount the DASD system on a z box. My IBM DS6800 manual states that a properly configured DS6800 can support 330,000 I/Os per second. Obviously, no one actually has a properly configured DS6800 (and I assume that the DS8*** boxes are even better).
My point is that the PC I/O system really pales compared to a modern mainframe. If your application needs to support 10,000 I/Os per second or so, you won't need the "tricks". And, of course, a good performance monitor can, more easily, point you to where any performance bottlenecks are. Tom Duerbusch THD Consulting On Tue, Oct 30, 2012 at 9:00 AM, David Boyes <[email protected]> wrote: > >But our Z enthusiast > > says we can put Redis and memcache on Z-Linux (under VM) without any > > loss of functionality or performance (because we have extra capacity and > > "paging on Z doesn't cost anything"). > > I'd agree on functionality, but performance is a harder question. Both > redis and memcache build and run fine on Z, no problems there. The trick is > that memory usage in a shared environment is much trickier to calculate the > impact of mass allocations of RAM -- depends a lot on where and how fast > you page, whether you have XSTOR or not, etc, etc, etc,. > > I'd try it with a smaller database and see how it goes. XSTORE will have a > measurable impact, as will use of VDISK for paging. > > ---------------------------------------------------------------------- > 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 > ---------------------------------------------------------------------- > For more information on Linux on System z, visit > http://wiki.linuxvm.org/ > -- ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
