[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] RE: [Xen-devel] some questions (xfrd, syslog, mem, preempt)
> 1) I found one line about that obscure xfrd in the "Xen Users' > manual": > > As xend runs, events will be logged to /var/log/ > /xend.log and, if the migration assistant daemon > (xfrd) has been started, /var/log/xfrd.log > > That's it, nothing in the FAQ. What is it? Why is it > started by "xend start"? Why is it listening on 0:8002? > If it is necessary, how can i bind it to localhost? If > not, how can i prevent it from being started? xfrd is needed for save/restore/migrate, and isn't needed otherwise. An option could be added such that it only binds to localhost, but the current assumption is that dom0's exist on a private VLAN. > 2) Can i configure xend to use syslog? xend.log's time- > stamps have non standard format, and xend-debug.log has > no timestamps at all. The log messages get written via python's logger package, which I believe can be configured quite flexibly. > 3) When i create a domain configured for "memory = 64" i > observe that "xm info" reports "free_memory" decreasing > exactly 64MB. But "xm list" reports that the domain > consumes 63MB, and /proc/meminfo even less (63136 kB). > This happens allways.Is the missing RAM consumed by the > Xen hypervisor? (I do not use the balloon driver, yet) The difference between xm list and xm info is robably just rounding differences. /proc/meminfo reports about Linux's internal allocation pool, so will always be smaller, just like on native. > Same goes for domain0: I boot with "dom0_mem=100000", > that should be 100000/1024 = 97.656MB, but "xm list" > reports 92MB for "Domain-0" and /proc/meminfo 94740kB, > at least 5MB missing. Dom0 gives back a few MB of memory after booting, as it wants to create certain unused 'guard frames' in it's memory map. I guess this is slightly confusing since dom0 will end up owning less memory than requested, but its not a big issue, and the memory isn't wasted and is available for other domains. > Is the difference between the sum of all gross (or net?) > domain memory footprints plus the "free_memory" and my > hosts RAM the memory consumption of the Xen hypervisor/ > microkernel (in my case it's 17MB)? For normal domains (those not using shadow page tables), Xen only needs about 100KB per domain. > 4) Any recommendations for CONFIG_PREEMPT and CONFIG_PRE- > EMPT_BKL? Or just the same as if the kernels would run > native, eg "If it runs a desktop use CONFIG_PREEMPT=y"? We run with both set to Y by default. > 5) By accident i had CONFIG_HANGCHECK_TIMER=y in my dom0. > That flooded the kernel log with "Hangcheck: hangcheck > value past margin!" Is that caused by the nature of Xen > to pause and unpause domains all the time? Yes, I suspect you don't want to enable this if you have multiple domains sharing a CPU. Nice questions, BTW. Ian ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_ide95&alloc_id396&op=click _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/xen-devel
|
![]() |
Lists.xenproject.org is hosted with RackSpace, monitoring our |