To begin: No "problem" per se at the moment. And thank you all for the tips and information on this list.
If no one objects I would like to promote myself from "newb with scars" to "clueless duffer."
I need to move forward on my builds and I have some xm dmesg items unresolved or misunderstoo.
I have 2 domU's loaded, both CentOS 5.3, one as image, one as LVM blocks. SELinux is On and Enforced in domUs (not yet in dom0). Apparently all is currently stable.
Xen version 3.1.2-128.1.16.el5 domO = CentOS 5.3 current Hardware = TYAN S2912G2NR mobo, AMD 2 x 2212, WD VelicoRaptors in Raid1
1) Are the below messages benign? I have read all over the place and they are quoted in immediate lockup or failure to boot situations. I have had not had a lockup or crash (after cleaning up the domU confs and services, zeroing hwclocks, etc.) in days.
(XEN) ioapic_guest_write: apic=0, pin=2, old_irq=-1, new_irq=0 (XEN) ioapic_guest_write: old_entry=00010000, new_entry=000009f0 (XEN) ioapic_guest_write: Installing bogus unmasked IO-APIC entry! (XEN) mm.c:649:d1 Error getting mfn 25654 (pfn 5555555555555555) from L1 entry 0000000025654025 for dom1 (XEN) mm.c:3327:d1 ptwr_emulate: fixing up invalid PAE PTE 0000000025654025 (XEN) mm.c:625:d2 Non-privileged (2) attempt to map I/O space 000cba6b (XEN) mm.c:3327:d2 ptwr_emulate: fixing up invalid PAE PTE 00000000cba6b025
2) I went back to HPET because there seems no harm/difference. Does this XM DMESG indicate Xen is "fixing" it, or do I have a loose end:
with HPET On (current state):
(XEN) ENABLING IO-APIC IRQs (XEN) -> Using new ACK method (XEN) Platform timer overflows in 8589 jiffies. (XEN) Platform timer is 25.000MHz HPET
with HPET Off:
(XEN) ENABLING IO-APIC IRQs (XEN) -> Using new ACK method (XEN) ..MP-BIOS bug: 8254 timer not connected to IO-APIC (XEN) works. (XEN) Platform timer overflows in 2 jiffies. (XEN) Platform timer is 1.193MHz PIT
Is HPET On and not setting clock to Jiffies going to bite me at some point?
3) I have been using the Apache ab "stress test" up to the edge of where I get cut off with synflood protection. My Xen servers will be primarily web applications and WAN services. When I first started test with ab I was able to provoke "Time goes backwards" reactions. I tweaked Xen and now I cannot crash or panic anything.
Is stress testing with ab an appropriate test for my environment and I can feel a bit more confident and move forward on my build?