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"J. Roeleveld" <joost@××××××××.org> writes: |
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> On Friday, April 24, 2015 10:24:06 PM lee wrote: |
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>> "J. Roeleveld" <joost@××××××××.org> writes: |
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>> > On Thursday, April 23, 2015 11:02:24 PM lee wrote: |
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>> >> hydra <hydrapolic@×××××.com> writes: |
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>> >> > You mean the documentation at Gentoo about Xen sucks or the upstream |
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>> >> > |
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>> >> > documentation? What information are you missing from there? Maybe we |
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>> >> > can |
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>> >> > add the missing pieces for Xen being more accessible and easier to |
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>> >> > use, |
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>> >> > what do you think? :) |
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>> >> |
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>> >> I mean the documentation they have on their wiki. It's a confusing mess |
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>> >> referring to various version with which things are being done |
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>> >> differently. |
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>> > |
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>> > The problem here is the different "implementations" that exist: |
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>> > - Xen (install and configure yourself, toolset: 'xl' , 'xm' is deprecated) |
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>> > - Citrix and XCP (pre-configured, install on dedicated server, toolset: |
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>> > 'xcp') - OVM (Oracle's implementation, not sure which toolset they use) |
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>> |
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>> Maybe, maybe not; the documentation is so confusing that I can't really |
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>> tell what it is talking about. |
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> |
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> Where did you look? |
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|
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Everywhere I could find. The xen wiki is particularly messy. |
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|
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>> >> Could you add missing pieces about why power management --- as in |
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>> >> frequency scaling --- doesn't work |
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>> > |
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>> > What doesn't work with this? |
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>> > The following seems quite detailed: |
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>> > http://wiki.xen.org/wiki/Xen_power_management |
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>> |
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>> There was some command to query what frequencies the CPUs are running |
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>> on, and it didn't give any output. Documentation seems to claim that |
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>> xen can do power management automagically, yet there was no way to |
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>> verify what it actually does. |
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> |
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> It works here: |
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> # xenpm get-cpufreq-para all |
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> cpu id : 0 |
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> affected_cpus : 0 |
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> cpuinfo frequency : max [3101000] min [1600000] cur [1600000] |
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> scaling_driver : acpi-cpufreq |
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> scaling_avail_gov : userspace performance powersave ondemand |
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> current_governor : ondemand |
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> ondemand specific : |
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> sampling_rate : max [10000000] min [10000] cur [20000] |
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> up_threshold : 80 |
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> scaling_avail_freq : 3101000 3100000 2900000 2700000 2500000 2300000 2100000 |
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> 1900000 1700000 *1600000 |
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> scaling frequency : max [3101000] min [1600000] cur [1600000] |
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> turbo mode : enabled |
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> |
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> <snipped identical results for other CPU-cores> |
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> |
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> Looks like it's actually working and I never configured this. |
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|
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It didn't work for me. |
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|
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>> > And the commands listed there (for the hypervisor based option) work on my |
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>> > server. |
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>> > |
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>> >> and what to do about keeping the time |
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>> >> in sync between all VMs when you find out that this doesn't work as the |
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>> >> documentation would have you think it does? |
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>> > |
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>> > In what way doesn't it work? |
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>> > The clocks are all synchronized and I don't need to use anything like |
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>> > 'ntpd' |
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>> The clocks were off by quite a bit after a while, and I had to use ntp |
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>> to get them in sync. Some documentation claims you don't need ntp or |
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>> anything; some other documentation apparently tries to explain that |
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>> keeping the clocks in sync cannot work unless the CPU(s) have some |
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>> features having to do with clock consistency while they are in sleep |
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>> states, and yet other documentation seems to say that using ntp cannot |
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>> work because xen screws it off. In the end, it was recommended to me to |
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>> use ntp, which I found to work. There was no way to figure out what xen |
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>> was actually doing or not doing towards this, and nobody seemed to know |
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>> how to keep the clocks in sync, other than using ntp, which appears to |
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>> be deprecated. |
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> |
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> Which version did you try? |
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> I remember having had clock-issues requiring ntp when I first started using Xen |
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> over 10 years ago. |
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|
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The version in Debian --- I don't remember which one it was. Debian was |
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the only distribution I could get it to work with at all, and the VMs |
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also were Debian because there isn't a good way to install an operating |
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system in a VM. |
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|
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-- |
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Again we must be afraid of speaking of daemons for fear that daemons |
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might swallow us. Finally, this fear has become reasonable. |
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