本教程旨在说明如何在 Ubuntu 9.04 系统上安装 Preload ，并使用它为系统提速。Preload 是一个自适应预读守护进程。它监控用户运行的应用程序，并且分析这些数据，，预测用户可能运行的程序，并读取这些程序的二进制文件及其依赖文件到系统内存，以达到加速启动的时间。
本文当不做任何形式的担保！我不保证它能在你的系统上正常工作！
安装 Preload
要安装 Preload ，首先打开终端 （应用程序/附件/终端），然后输入：
sudo aptitude install preload
来安装 Preload 。
安装完成。Preload 将在后台静静运行。如果你想改变 Preload 的行为，你可以编辑它的配置文件 /etc/preload.conf 。这是它的默认配置：
sudo gedit /etc/preload.conf
[model]
# cycle:## This is the quantum of time for preload. Preload performs# data gathering and predictions every cycle. Use an even# number.## Note: Setting this parameter too low will may reduce the# system performance and stability.## unit: seconds# default: 20#cycle = 20
# usecorrelation:## Whether correlation coefficient should be used in the prediction# algorithm. There are arguments both for and against using it.# Currently it’s believed that using it results in more accurate# prediction. The option may be removed in the future.## default: trueusecorrelation = true
# minsize:## Minimum sum of the length of maps of the process for# preload to consider tracking the application.## Note: Setting this parameter too high will make preload less# effective, while setting it too low will make it eat# quadratically more resources, as it tracks more processes.## unit: bytes# default: 2000000#minsize = 2000000
## The following control how much memory preload is allowed to use# for preloading in each cycle. All values are percentages and are# clamped to -100 to 100.## The total memory preload uses for prefetching is then computed using# the following formulae:## max (0, TOTAL * memtotal + FREE * memfree) + CHACED * memcached# where TOTAL, FREE, and CACHED are the respective values read at# runtime from /proc/meminfo.#
# memtotal: precentage of total memory## unit: signed_integer_percent# default: -10#memtotal = -10
# memfree: precentage of free memory## unit: signed_integer_percent# default: 100#memfree = 100
# memcached: precentage of cached memory## unit: signed_integer_percent# default: 30#memcached = 30
###########################################################################
[system]
# doscan:## Whether preload should monitor running processes and update its# model state. Normally you do want that, that’s all preload is# about, but you may temporarily want to turn it off for various# reasons like testing and only make predictions. Note that if# scanning is off, predictions are made based on whatever processes# have been running when preload started and the list of running# processes is not updated at all.## default: truedoscan = true
# dopredict:## Whether preload should make prediction and prefetch anything off# the disk. Quite like doscan, you normally want that, that’s the# other half of what preload is about, but you may temporarily want# to turn it off, to only train the model for example. Note that# this allows you to turn scan/predict or or off on the fly, by# modifying the config file and signalling the daemon.## default: truedopredict = true
# autosave:## Preload will automatically save the state to disk every# autosave period. This is only relevant if doscan is set to true.# Note that some janitory work on the model, like removing entries# for files that no longer exist happen at state save time. So,# turning off autosave completely is not advised.## unit: seconds# default: 3600#autosave = 3600
# mapprefix:## A list of path prefixes that controll which mapped file are to# be considered by preload and which not. The list items are# separated by semicolons. Matching will be stopped as soon as# the first item is matched. For each item, if item appears at# the beginning of the path of the file, then a match occurs, and# the file is accepted. If on the other hand, the item has a# exclamation mark as its first character, then the rest of the# item is considered, and if a match happens, the file is rejected.# For example a value of !/lib/modules;/ means that every file other# than those in /lib/modules should be accepted. In this case, the# trailing item can be removed, since if no match occurs, the file is# accepted. It’s advised to make sure /dev is rejected, since# preload doesn’t special-handle device files internally.## default: (empty list, accept all)mapprefix = /usr;/lib;!/
# exeprefix:## The syntax for this is exactly the same as for mapprefix. The only# difference is that this is used to accept or reject binary exectuable# files instead of maps.## default: (empty list, accept all)exeprefix = !/usr/sbin;!/usr/local/sbin;/usr;!/
如果你更改了配置，你需要重启 Preload ：
sudo /etc/init.d/preload restart
链接
preload: Ubuntu:翻译自 Speed Up Your System With Preload On Ubuntu 9.04 ，不保证翻译的准确性，请查看原文。
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我也相信爱可以排除万难;只是，万难之后，又有万难。这是我更相信的。
