On Saturday 16 January 2010 00:13:58 ltsp-discuss- [email protected] wrote: > I have a problem that is not show-stopping, but annoying nevertheless. > Perhaps the smart people here can give me a hint as to what's going > on. > > Network: > 15 HP thin clients > 1 Ubuntu 9.04 x86_64 server running on ESXi with 1-core virtual Xeon > 5250, 1GB RAM, GBE > Windows Server 2008 on ESXi with dual-dual Xeon 5250, 12 GB RAM, GBE > > If I boot a single tc at one time I see what looks like a normal boot > and the Windows logon screen appears within a minute. However > occasionally, or always when booting more than one tc simultaneously, > the progress bar on the Ubuntu splash screen will stall around 20%, > then the splash screen will give way after a few seconds to a text > console, where I see the following: > > Disconnecting: que, disconnect, sock, done > Negotiation: _ > > And then after some period of time the tc finishes booting normally > and all is well. The delay is approximately equal to 1 minute per > extra booting client. In other words, if I reboot all 15 > simultaneously, it is generally about 15 minutes before all are back > at the login screen. > > My first suspicion for bottleneck was disk access, although it didn't > really seem like a huge load for a server with an 8-SAS RAID5 array. I > tested this hypothesis by mounting /opt/ltsp/images as a ramdisk and > copying i386.img into it. Now I see a network activity spike on the > server when clients are booted, but no disk activity, as expected, but > the delay is the same. > > Likewise, the CPU (top) and network (gnome system monitor, ESXi) > actually read idle during this group boot, but the observed delay > remains the same. Flow control is off on the server and switches, > although it shouldn't matter because the network is passing <1mbit > during this delay. > > What do you think could be happening? There is definitely a > peer-dependent delay when booting these thing. There must be some > contention going on during a mass (>1) boot, but I don't know where > else to look. Any ideas?
Dave I cannot recall what we did, it was easy to find in the man, but the servers have DenialOfService delays built in. We increased the number of simultainious clients I think on DHCP. Wireshark is easy to use and very helpful to show exactly what is happening. James ------------------------------------------------------------------------------ Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev _____________________________________________________________________ Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: https://lists.sourceforge.net/lists/listinfo/ltsp-discuss For additional LTSP help, try #ltsp channel on irc.freenode.net
