Since we upgraded our system to Fedora 7 both available kernels seem very unstable. We have tried 2.6.21-1.3194.fc7 as well as 2.6.21-1.3228.fc7. Unfortunately we cannot describe the error in more detail but that it just hangs. Over the serial connection the system is not responding anymore as well as on the VGA console. It usually happens after about 36 hours and then the system is not reachable anymore. The system is a quad amd dual-core system: processor : 7 vendor_id : AuthenticAMD cpu family : 15 model : 65 model name : Dual-Core AMD Opteron(tm) Processor 8214 stepping : 2 cpu MHz : 2200.283 cache size : 1024 KB physical id : 3 siblings : 2 core id : 1 cpu cores : 2 Dell Poweredge 6950 8GB RAM The load is most of the time rather high. This is a mirror server and we are pushing about 300Mbit/s as an average. With much higher peaks possible. There is a fiber channel RAID with 4TB attached and 1TB iscsi volume. We used bonding during FC6 but due to https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=241719 we disabled it. We have a dual port e1000 for our main traffic and the internal bnx2 dual port is used for the iscsi connection. Our system is stable with the latest 2.6.18 from FC6 but newer FC6 kernels were never tried because of https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=225399 We are writing some values to proc with sysctl for performance reasons: net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_tw_recycle = 1 net.ipv4.tcp_fin_timeout = 30 net.ipv4.tcp_keepalive_time = 1800 net.core.wmem_max = 8388608 net.core.rmem_max = 8388608 net.ipv4.tcp_rmem = 4096 87380 8388608 net.ipv4.tcp_wmem = 4096 87380 8388608 net.ipv4.tcp_max_syn_backlog = 4096 vm.min_free_kbytes = 65536 We have not tried changing these values because they have proofed to be good with the 2.6.18 kernel. I have no idea if these values are the reason for our hangs. I am aware that this is a bad bug report and you can close if you like. I just wanted to report it. Currently we are happy with 2.6.18.
Created attachment 158428 [details] lspci output I'm having a similar problem on a copule of FC7 machines, most recently on a Dell Optiplex GX270 with kernel-2.6.21-1.3228.fc7 - complete lock up no output on serial console. Has also happened at run level 3 (so no X). I've attached the output of lspci for the GX270 as it might help correlate issues with specific hardware.
We've been having trouble with random system hangs on Acer Veriton 5800 workstations. These have a pentium D (3.4Ghz) processor. setting maxcpus=1 at boot, seems to stop this from happening. We;ve noticed the the same problem with FC6 machines running a kernel later than 2.6.20.
With 2.6.22.4-65.fc7 we have now a uptime of two weeks. Seems to be fixed. Closing it.