On Feb 22, 2007, at 1:23 PM, Dave Hansen wrote:
A). VM Memory Disk (VDISK). Currently we do not use VDISK for our production zLinux servers on our z/VM 5.2 system. I see SLES 10 recommends two VDISKs. Is there a downside to using VDISK? About the only thing I saw is that VDISK doesn't do expansion or contraction, so you may need to "monitor" its usage. The popular thing I can see is to VDISK the swap filesystem, which we don't do. It sounds to me that even if you only have one zLinux you want to use VDISK (at least for swap).
Absolutely.
B). Shared Kernel. This is an NSS and not just a DCSS for the filesystems like "/var" (I think "/" or root is not supported in a DCSS anymore). So this is what I IPL. If it's not there, I can't IPL. We have been kicking this idea around for a while. But with only a dozen penguins of different configurations (WebShere or not, monitors etc.), I'm not sure we would gain much. Again I looked at what it costs. I found this in the IBM literature: "Every virtual machine that IPLs your shared system must have the same disk configuration as the system that was saved. That is, the disks must be at the same addresses and be the same sizes as the virtual machine that issued the SAVESYS command". What this means to me is we need every zLinux that IPLs the NSS has to have the same filesystems (in size and number). Furthermore I found that previously it looks like LKCD (Suse Crash Dump) didn't work well when you IPLd an NSS. All I can find now is that there appears to be a new LKCD2. I also found LKDTT, but it requires a kernel patch and a kernel re-compile. I thought re-compile = unsupported (tainted) zLinux? So then who would want your dump? Do we need to re-compile the kernel for "crash dump" support? Does it matter if we IPLd from an NSS? Are there any kernel parameters related to using an NSS? I saw a post from this year that talks about "Boot from NSS support" and a parameter "SAVESYS=". If we go through with this for only a few penguins is this worth it (besides having a good procedure to grow the farm)?
For only a few penguins, no, not really. Building from the same sources won't *taint* your kernel (the drivers are GPL after all), but it might make it unsupported. Adam ---------------------------------------------------------------------- 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
