similar to: Monitoring time drift of hosts

Hello, On a xenserver with several (39) domUs, we experience problems with the system clock of the domUs. The clock seems to drift away several seconds up to two minutes from the dom0 clock. We do have set independent_wallclock=0. According to the docs (i.e. http://wiki.xensource.com/xenwiki/InstallationNotes) that way domUs should use the dom0 clock, but apparently that''s not the case.

Hello, What is for you the best GlusterFS scenario in using XenServer (i'm not talking about Xen on a linux but XenServer baremetal) for a web farm (Apache-Tomcat) ? I were thinking of using ZFS as the filesystem for the different nodes. The objectives/needs : * A storage cluster with the capacity equal to at least 1 node(assuming all nodes are the same). * being able to lose/take down any

Supermicro X7DWN+, XEON 5410, Centos 5.2, Xen 3.2.1 At what looks like random times network traffic over xen bridge stops working, the only way I found to fix it is a reboot. This sometimes takes 10 min, other times it may be up for 10 days. This happened with default xen that comes with RedHat EL 5.2 as well as a default install of Fedora 8. Any ideas? ><> Nathan Stratton

I have 6 boxes with a client config (see below) across 6 boxes. I am using distribute across 3 replicate pairs. Since I am running xen I need to disable-direct-io and that slows things down quite a bit. My thought was to move the replicate / distribute to the backend server config so that self heal can happen on faster backend rather then frontend client with disable-direct-io. Does this

Hello folks, I am running Xen 2.6 under Centos 5.2 installation, and am trying to port Xen migration abilities to Infiniband. But, the InfiniBand drivers do not work under Xen kernel, only under non-Xen kernels. It looks like I need to install some patches to rectify the situation. Has anyone ever worked with Infiniband and Xen and would be able to give me inputs about the same? I would really

Lets say you had 4 servers and you wanted to setup replicate and distribute. What methoid would be better: server sdb1 xen0 brick0 xen1 mirror0 xen2 brick1 xen3 mirror1 replicate block0 - brick0 mirror0 replicate block1 - brick1 mirror1 distribute unify - block0 block1 or server sdb1 sdb2 xen0 brick0 mirror3 xen1 brick1 mirror0 xen2 brick2 mirror1 xen3 brick3 mirror2 replicate block0 -

Greetings. I''ve reviewed the list archives, particularly the posts from Zakk, on this subject, and found results similar to his. drbd provides a block-drbd script, but with full virtualization, at least on RHEL 5, this does not work; by the time the block script is run, the qemu-dm has already been started. Instead I''ve been simply musing the possibility of keeping the drbd

Hello Everyone, I recently had a question that got no responses about GFS+DRBD clusters for Xen VM storage, but after some consideration (and a lot of Googling) I have a couple of new questions. Basically what we have here are two servers that will each have a RAID-5 array filled up with 5 x 320GB SATA drives, I want to have these as useable file systems on both servers (as they will both be

I am experiencing strange network behavior from several DomU''s. I can ssh from DomU to any host on the local lan/vlan, I can ping those hosts. However when I go to resolve a hostname DNS fails. I have verified that three other DomU''s are exhibiting the same behavior. I have also verified that Dom0 is functioning properly and can resolve hostnames and access hosts outside of the

Hi On 5.3 i have a situation where some boxes have been 3 or 4 seconds out and restarting ntpd has fixed the issue. What i dont understand is why the clocks did not drift to the correct time when the config seems correct in that restarting ntp did correct the time. Is there something 'special' i need to do in order for the drift to work? $ cat /etc/ntp.conf restrict default

Hi, I've noticed that one of my new servers (new mobo) if drifting slowly backwards in time (in aprox. 24 hours, system time drifts back 5 minutes). I have an ntpd process which is supposed to sync with a lan time server but it's not quite working. So I'm launching a manual ntpdate or ntp-client once an hour and that seems to work. However, suppose I update system time at every hour

I'm trying to justify a GlusterFS storage system for my technology development group and I want to get some clarification on something that I can't seem to figure out architecture wise... My storage system will be rather large. Significant fraction of a petabyte and will require scaling in size for at least one decade. from what I understand GlusterFS achieves redundancy through

Hi All, Sorry again to bother you with this but there is really something I don't fully understand about client/server clock syncs. If I connect to the stream with a fresh browser, I can measure between 5-10 secs latency. I keep listening to it for while, and the delay between server and client grows as listening is going on. As pointed out Philipp yesterday to me, it's approximately a 5%

Hello everyone! I been observing some peculiar time drift on my Xen domains (dom0 and domUs). The time (as returned by timeofday) on my domains drifts at an almost steady rate from the real time ( as read from the time stamp counter ). The drift is so constant that it makes me think there should be some simple explanation for it in the way Xen keeps time. Some info about my set up: guest OS:

We have a local time server and all of our machines are pointed at it for the time. How can the clock drift by a day and a half? [root at devserver21 ~]# date Fri Aug 13 14:43:29 EDT 2010 [root at devserver21 ~]# rdate -s 192.168.1.67 [root at devserver21 ~]# date Thu Aug 12 07:02:39 EDT 2010 [root at devserver21 ~]# cat /etc/ntp.conf | grep -v ^# | grep -v ^$ restrict default nomodify notrap

In english: Buddies, The Eucalyptus is a system to build a cluster and provide a service such as Amazon EC2 on its own structure. It is very promising, flexible, stable and well documented. The team of Eucalyptus just created an Internet election to choose which distributions will be officialy supported by it. I would ask everyone for voting in Debian! Let me explain why. I have

In english: Buddies, The Eucalyptus is a system to build a cluster and provide a service such as Amazon EC2 on its own structure. It is very promising, flexible, stable and well documented. The team of Eucalyptus just created an Internet election to choose which distributions will be officialy supported by it. I would ask everyone for voting in Debian! Let me explain why. I have

Dear R-Users, I have the following problem to solve and I wonder if there are means in R that can help me. At irregular time intervals I observe a random walk process, Y, with time-varying drift. I assume that the drift, D, is a (linear) function of some parameter X. The goal is to estimate D(X). I could regress Y_{t+dt} - Y_{t} ~ X, but it's probably not appropriate since Var(Y_{t+dt} -

I have been trying to simulate from a time series with trend but I don't see how to include the trend in the arima.sim() call. The following code illustrates the problem: # Begin demonstration program x <- c(0.168766559, 0.186874000, 0.156710548, 0.151809531, 0.144638812, 0.142106888, 0.140961714, 0.134054659, 0.138722419, 0.134037018, 0.122829846, 0.120188714,

1. Shouldn''t the GPLPV drivers take care of the (bad) clock drift I''m experiencing in my Windows XP HVM? Or is there some other way around this problem that I haven''t been able to find on Google? How can I tell if the GPLPV drivers are active? I''ve added the /gplpv switch to the boot.ini file and the virtual NIC is definitely using the GPLPV version but other