linux下的fastcopy
在拷贝数据的时候,如果遇到一堆小文件,即使总数据量很小,拷贝也会很费时,在win下,有一个软件叫fastcopy,可以实现快速拷贝,据说使用了一种叫内存映射的技术,那么在Linux下有没有呢?
我找了半天,原来LInux下根本不需要单独的软件,用现有的命令组合就OK了!
有高手在两个服务器间传数据,使用命令,实现了快速传送数据。
http://www.4bcj.com/post/2008/01/Fast-File-Copy—Linux!.aspx
All good ideas come out of necessity. We were cloning an instance of
Oracle Financials from one server to another. There are a LOT of files
under < 1k and the copy takes forever. Yesterday the copy was kicked
off using SCP - there was 39GBs to copy over a gigabit switch. This
should have been less than 10 minutes but actually took over 8 hours
because of all the small files. The copy failed and we needed to fix
the problem and copy it a lot faster (30 minutes) today.
After clearing up 10 GBs of log files, we were left with hundreds of
thousands of small files that were going to slow us down. We couldn’t
tarball the file because of a lack of space on the source server. I
started searching around and found this nifty tip that takes our
encryption and streams all the files as one large file:
This requires netcat on both servers.
Destination box: nc -l -p 2342 | tar -C /target/dir -xzf -
Source box: tar -cz /source/dir | nc Target_Box 2342
It’s been about 4 minutes and I’m already 1/3 of the way done!
感谢本校LInux版主ashmer,写了这个shell脚本,可以实现fastcopy, 与诸位共享.
#!/bin/sh
# file: fastcp.sh
source="$1"
target="$2"
if [ "x$1" == "x" ] || [ "x$2" == "x" ] ; then
echo "$0 SOURCE_DIR TARGET_DIR"
exit 1
fi
exec tar -cp "$source" -f - | tar -xpv -C "$target" -f -
#end
PS: 测试了一番,速度竟然由cp的0m21.270s降低至0m6.984s,真是够快的。。。
相关文档:
1. HCI层协议概述:
HCI提供一套统一的方法来访问Bluetooth底层。如图所示:
从图上可以看出,Host Controller Interface(HCI) 就是用来沟通Host和Module。Host通常就是PC, Module则是以各种物理连接形式(USB,serial,pc-card等)连接到PC上的bluetooth Dongle。
在Host这一端:application,SDP,L2cap等协议 ......
Service Discovery Protocol(SDP)提供一种能力,让应用程序有方法发现哪种服务可用以及这种服务的特性。
服务发现协议(SDP或Bluetooth SDP)在蓝牙协议栈中对蓝牙环境中的应用程序有特殊的含意,发现哪个服务是可用的和确定这些可用服务的特征。SDP定义了bluetooth client发现可用bluetooth server服务和它们的特征的方法。 ......
一:前言
最近在研究android的sensor driver,主要是E-compass,其中用到了Linux input子系统.在网上也看了很多这方面的资料,感觉还是这篇分析的比较细致透彻,因此转载一下以便自己学习,同时和大家分享!
(这篇博客主要是以键盘驱动为例的,不过讲解的是Linux Input Subsystem,可以仔细的研究一下!)
键盘驱动将检 ......
作者:fbysss
msn:jameslastchina@hotmail.com
blog:blog.csdn.net/fbysss
声明:本文由fbysss整理编写,转载请注明出处
关键字:shell编程
背景
同事求助。
需求
一个文本文件,要得到最后一行与倒数第一行相减的结果。
测试文 ......
参考网址:
http://trac.edgewall.org/wiki/TracInstall
http://trac.edgewall.org/wiki/TracInstallPlatforms
http://trac.edgewall.org/wiki/TracOnRhel5
http://dag.wieers.com/rpm/FAQ.php#B
http://tech.idv2.com/2008/12/26/install-trac-on-linux/
软件下载地址:
trac:http://trac.edgewall.org/wiki/TracDo ......