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ASR XD报警抛出如下错误

"
dm01cel02: Hardware Error has been detected in the Flash Logs on the Cell Node
dm01cel02: Please open up a Service Request with Oracle to resolve the Error
dm01cel02: View File /tmp/ASR-Flash-Fault-Check-Log for further Information of the Error
dm01cel02: This log File c[......]

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Nmap (“Network Mapper”) is an open source tool for network exploration and security auditing. It was designed to rapidly scan large networks, although it works fine against single hosts. While Nmap is commonly used for security audits, many systems and network administrators find it useful for routi[......]

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对于业务的激活码需求做了一次关于mysql,mongodb的比对.mysql分为normal,key partition 数量分别是1亿和10亿数据,mysql采用直接访问PK键,partition key为PK,mysql table size 为90G,mongodb table size为157G。

[liuyang@yhdem ~]$ cat /proc/cpuinfo  |grep processor |wc -l
24

[liuyang@yhdem ~]$ cat /etc/issue
Oracle Linux Server release 5.8
Kerne[......]

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iotop是一个类似top的检测process IO 的Python 项目。可以在这里下载到源码,可以在这里找到具体的说明。下面做一个演示：

首先下载源码,要求python version>=2.6

wget http://guichaz.free.fr/iotop/files/iotop-0.5.tar.gz
wget http://www.python.org/ftp/python/2.6.6/Python-2.6.6.tgz

编译python

[root@oel58 tmp]# cd /tmp/Python-2.6.6
[root@oel58 Python[......]

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pidstat是一款很不错的针对linux pid状态监控的程序

The pidstat command is used for monitoring individual tasks currently being managed by the Linux kernel.
It writes to standard output activities for every task selected with option -p or for every task managed by the Linux kernel if option -p ALL has been used.[......]

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本来想写一篇关于nicstat的文章,霸爷已经写的非常好了参考这里nicstat 网络流量统计利器

这里说明一下使用nicstat 可以完美替代iptraf ,nload 等工具

同样可以替代watch –命令行模式:
eg:

Every 1.0s: /sbin/ifconfig eth0 | grep bytes                                                                                                                           Wed Feb[......]

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Perf is a profiler tool for Linux 2.6+ based systems that abstracts away CPU hardware differences in Linux performance measurementsand presents a simple commandline interface. Perf is based on the perf_events interface exported by recent versions of the Linux kernel. This article demonstrates the pe[......]

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+------------+----------+-------------+------------+-------------+-------------+
|bps         |B/s       |network      |storage     |port         |bus          |
+------------+----------+-------------+------------+-------------+-------------+
|56/48K      |5.6/4.8K  |Modem 56k    |            |[......]

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mysql 数据库 poor IO performance.从DELL 815(6disk raid 5,oel5.5) 迁移至 HP DL380 (14disk raid 1+0,rhl5.8)

当时的IO 表现

avg-cpu:  %user   %nice %system %iowait  %steal   %idle
           4.55    0.00    1.30    0.25    0.00   93.90

Device:         rrqm/s   wrqm/s   r/s   w/s    rkB/s    wkB/s avgrq[......]

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11g ADG 给了大家更多的灾备选择,包括之前美国飓风,给了ADG大放光彩的机会,但是ADG并没有想象中的那么完美,以下是最近的一个CASE,具体过程不详写了,目前这个case还在跟进中,记录之：

[oracle@dcb-srv-0174 trace]$ cat itemstd02_ora_22156.trc |grep "LibraryObjectLock" |awk '{print $3 "-- obj handle get"}' | uniq -c |awk  '{ if ($1>100) print $[......]

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