Apr 22

CentOS 5.4 released

By jason Linux/Unix Oprating system No Comments »

Almost two months after RHEL5.4, Centos 5.4 was released on the 21st October. This version includes various changes into the virtualization field and it includes support for KVM (kernel-based virtual machine) hypervisor and the Xen hypervisor.

Also this release features many bug fixes and security updates, and should be an easy upgrade for users running centos5.x:
yum update

For the full list of packages changed/added please see the centos5.4 release notes: http://wiki.centos.org/Manuals/ReleaseNotes/CentOS5.4

Tagged with: •
Apr 06

how to resolve kernel: printk: xxx messages suppressed

By jason Linux/Unix Oprating system No Comments »

I find a lot of error log on my proxy server:

Jan 22 22:57:37 streams1 kernel: printk: 1 messages suppressed.
Jan 22 23:00:04 streams1 kernel: printk: 1 messages suppressed.
Jan 22 23:00:09 streams1 kernel: printk: 1 messages suppressed.
Jan 22 23:00:13 streams1 kernel: printk: 3 messages suppressed.
Jan 22 23:00:20 streams1 kernel: printk: 2 messages suppressed.
Jan 22 23:00:25 streams1 kernel: printk: 3 messages suppressed.
Jan 22 23:00:29 streams1 kernel: printk: 2 messages suppressed.
Jan 22 23:00:34 streams1 kernel: printk: 2 messages suppressed.
Jan 22 23:00:45 streams1 kernel: printk: 3 messages suppressed.

It’s normal after I change kernel parameters.

1.ip_conntrack_tcp_timeout

echo 180 > /proc/sys/net/ipv4/netfilter/ip_conntrack_tcp_timeout_established

2. ip_conntrack_max
echo 262144 > /proc/sys/net/ipv4/netfilter/ip_conntrack_max

3.gc_stale_time
echo 120   > /proc/sys/net/ipv4/neigh/default/gc_stale_time

4.gc_thresh1
echo 1024 > /proc/sys/net/ipv4/neigh/default/gc_thresh1

5.gc_thresh2
echo 4096 > /proc/sys/net/ipv4/neigh/default/gc_thresh2

6.gc_thresh3
echo 8192 > /proc/sys/net/ipv4/neigh/default/gc_thresh3

Tagged with: • •
preload preload preload