德瑞克的技術大小事: 6月 2013

2013年6月28日星期五

ssh -i identity-file(private-key)

-i identity_file

Selects a file from which the identity (private key) for RSA or DSA authentication is read. The default is $HOME/.ssh/identity for protocol version 1, and $HOME/.ssh/id_rsa and $HOME/.ssh/id_dsa for protocol version 2. Identity files may also be specified on a per-host basis in the configuration file. It is possible to have multiple -i options (and multiple identities specified in configuration files).

PYTHON: range() vs xrange()

1. range 是全部產生完後，return一個 list 回來使用。
2. xrange 是一次產生一個值，並return一個值回來，所以xrange只適用於loop。

http://falldog7.blogspot.tw/2009/07/python-range-xrange.html

2013年6月27日星期四

novncproxy套件安裝衝突解決辦法

dpkg -i --force-overwrite /var/cache/apt/archives/nova-novncproxy_1%3a2013.1-0ubuntu2~cloud1_all.deb

https://answers.launchpad.net/nova/+question/228890

AWS AMI/AKI/ARI之介紹

AMI (Amazon Machine Image) This is a virtual machine image in raw format, as
described above.
AKI (Amazon Kernel Image) A kernel file that the hypervisor will load initially to boot
the image. For a Linux machine, this would be a vmlinuz
file.
ARI (Amazon Ramdisk Image) An optional ramdisk file mounted at boot time. For a
Linux machine, this would be an initrd file.

2013年6月23日星期日

[Quantum] quantum ovs-plugin agent的問題: br-int is not a bridge or a socket

https://github.com/mseknibilel/OpenStack-Folsom-Install-guide/issues/75

https://wiki.openstack.org/wiki/ConfigureOpenvswitch

https://answers.launchpad.net/quantum/+question/181070

https://answers.launchpad.net/quantum/+question/205427

2013年6月19日星期三

半虛擬化(para-virtualization) vs 全虛擬化(full-virtualization)

para-virtualization

full-virtualization

http://werdna1222coldcodes.blogspot.tw/2012/10/full-para-virtualization.html

2013年6月18日星期二

Xenserver RRDs

Xenserver所使用的RRD Consolidation Function(CF)共有:
1. Average
2. Min
3. Max

There exist RRDs for individual VMs (including dom0) and the host. The VM RRDs are stored on the host on which they run, or the pool master when they are not running. This means that the location of VM must be known in order to retrieve the associated performance data.

DS Field Definitions:

DS	Defines a Data Source Field.
DS-Name	The name of this Data Source.
DST	Defines the Data Source Type. Can be GAUGE, COUNTER, DERIVE or ABSOLUTE.
HeartBeat	Defines the minimum heartbeat, the maximum number of seconds that can go by before a DS value is considered unknown.
Min	The minimum acceptable value. Values less than this number are considered unknown. This is optional.
Max	The maximum acceptable value. Values exceeding this number are considered unknown. This is optional.

DS欄位格式為"三文字，三數字"

ex:
DS:telnet:COUNTER:600:0:100000000
(DS-Name) (DST) (HeartBeat) (Min) (Max)

RRA

RRA means round robin archive. Defining an RRA is the tricky part!

This parameter describes how long you want to hold your data, and in what resolution. There can be more than on archive. If the time span of an archive is full, the data will be consolidated and saved into the next archive.

The format is

RRA:CF:xff:steps:rows

http://community.citrix.com/display/xs/Graphing+RRD+with+GNUPlot
http://community.citrix.com/display/xs/Getting+the+Last+RRD+Datapoints
http://community.citrix.com/display/xs/Using+XenServer+RRDs

2013年6月17日星期一

mysql資料庫的授權(grant)

grant all privileges on '資料庫'.'表格名' to ' 帳戶'@'主機' identified by '密碼';

上傳tag到遠端的repo

上傳標籤到遠端

git push 並不會把標籤上傳到遠端，所以必須透過底下才行

$ git push origin v1.5

Counting objects: 50, done.

Compressing objects: 100% (38/38), done.

Writing objects: 100% (44/44), 4.56 KiB, done.

Total 44 (delta 18), reused 8 (delta 1)

To git@github.com:schacon/simplegit.git

* [new tag]         v1.5 -> v1.5

如果在本機端很多標籤，利用 –tags 一次上傳上去

$ git push origin --tags

Counting objects: 50, done.

Compressing objects: 100% (38/38), done.

Writing objects: 100% (44/44), 4.56 KiB, done.

Total 44 (delta 18), reused 8 (delta 1)

To git@github.com:schacon/simplegit.git

 * [new tag]         v0.1 -> v0.1

 * [new tag]         v1.2 -> v1.2

 * [new tag]         v1.4 -> v1.4

 * [new tag]         v1.4-lw -> v1.4-lw

 * [new tag]         v1.5 -> v1.5

http://blog.wu-boy.com/2010/11/git-%E7%89%88%E6%9C%AC%E6%8E%A7%E5%88%B6-%E5%A6%82%E4%BD%95%E4%BD%BF%E7%94%A8%E6%A8%99%E7%B1%A4tag/

2013年6月15日星期六

Python基礎心法: list與dict的初始化宣告

dict

x = {}

list

x = []

指數平滑法

指數平滑法可以分成:
1. 一次指數平滑法
2. 二次指數平滑法
3. 三次指數平滑法

CA Server的種類

Self-Signed CA
亦可稱為 root CA。由於此種 CA 所發的憑證(certificate)是不經由任何上層 CA 所認證，而是以「自行認證」的方式進行認證。因此像是最上層的商業 CA，或是自行架設內部認證用的 CA，都可以屬於此類。
Signed CA
不同於 Self-Signed CA，此種 CA 所發佈的憑證，可被上層的 CA 進行認證，而兩種 CA 的關係則是「Parent CA <==> Child CA」。而通常設定上層 CA 時，除非是內部使用，不然使用商業 CA 是必須付費的!

http://godleon.blogspot.tw/2007/05/ca-certificate-certificate.html

2013年6月13日星期四

ceilometer監控的資料類型

Type	Definition
Cumulative	Increasing over time (instance hours)
Gauge	Discrete items (floating IPs, image uploads) and fluctuating values (disk I/O)
Delta	Changing over time (bandwidth)

Linux系統附載均值

load average: 0.09, 0.05, 0.01

             (1min)(5min) (15min)

Reference

http://www.gracecode.com/posts/2973.html

2013年6月11日星期二

STP: Spanning Tree Protocol

http://blog.xuite.net/alexx.huang/solution/33077662-STP+(Spanning+%E2%80%93+Tree+Protocol)+

2013年6月9日星期日

RRDTools

RRDTools = Round-Robin Database Tools的縮寫

handle time-series data like network bandwidth,temperatures, CPU load, etc. The data are stored in a round-robin database (circular buffer), thus the system storage footprint remains constant over time.

Reference:

1. RRDtools tutorial, http://oss.oetiker.ch/rrdtool/tut/

OpenStack: Cloud Inventory Manager

CloudInventoryManager

https://wiki.openstack.org/wiki/CloudInventoryManager

2013年6月6日星期四

[英文] provide的語法

provide X for 人

provide X with 東西

nova: virtapi

在nova中virtapi的定義放在/usr/share/pyshared/nova/virt/virtapi.py當中，只是用來制定api的spec

英文: 先行詞

先行詞是指句子中被一個跟在後面的代名詞所代替的字群；這個字群通常是個名詞及其修飾語。

http://www.taiwantestcentral.com/Grammar/Title.aspx?ID=236

2013年6月1日星期六

OpenStack Xenserver Host Aggregate 建置筆記

所謂的Xenserver Host-Aggregte目的是為了讓Compute Node能利用Xensever Resource Pool的概念集結起來，在掛載像是NFS Share的SR以便做Live-migration或是VM-RESIZE。

1. 在XenServer Host上先製作出PV的Nova Compute Node + quantum-plugin-openvswitch-agent
(ubuntu 12.04 LTS )
2. 然後再將要建置成resource pool的所有compute node中的/etc/nova/nova.conf加入以下的設定:
sr_matching_filter = default-sr:true

3. 再來利用aggregate-create在availability zone中建置邏輯資源池(logical resource pool)
nova aggregate-create <pool-name> <availability-zone>

4. 再來設定host-aggregate的metadata，告訴nova controller我要建置的是xenserver resource pool:
nova aggregate-set-metadata <pool-id> hypervisor_pool=true
nova aggregate-set-metadata <pool-id> operational_state=create

5. 從所有的計算節點當中選出一個當作Master ComputeNode:
nova aggregate-add-host <pool-id> <master-compute-node>

6. 其他後續加入的compute node會成為slave compute node:
nova aggregate-add-host <pool-id> <slave-compute-node>

Reference:
1. http://docs.openstack.org/trunk/openstack-compute/admin/content/configuring-migrations.html#true-live-migration-kvm-libvirt

AMQP

http://lab.howie.tw/2012/07/whats-different-between-amqp-and-jms.html

訂閱：文章 (Atom)

2013年6月28日 星期五

2013年6月27日 星期四

2013年6月23日 星期日

2013年6月19日 星期三