ubiquitous  普遍存在的

gadget      小机件

we have almost come to take disk drives for granted as ubiquitous gadget that are redily available at volume discounts.

subassembly  部件，组件

platter      大浅盘

actuator     执行器

spindle      轴，纺锤

servo        伺服

rigid        严格的，僵硬的，刻板的

substrate    基片，底层

microscopical 显微镜的

alloy        合金  aluminum/magnesium alloy

magnesium    镁

vibration    震动

proximity  接近，亲近  proximity to the CPU

volatile   易失性，易挥发的，稍纵即逝的  non-volatile RAM   volatile RAM

peripheral 不重要的，外围，外围设备

traction   牵引，牵引力   market traction

convoluted 旋绕的，费解的

HBA        hosted bus attachment

imprint    刻上记号，印记

perplex    使困惑，使更复杂，使为难   are often perplexed by the complexity involved.

primitive  原始的  Kernel process are sometimes referred to as 'primitive'

subroutine 子程序

vigorous   精力充沛的

smack      滋味，风味，少量

intricate  复杂的，难懂的

compart

DAS: direct attached storage

NAS: network attached storage

SAN: storage area network

SCSI: small computer system interface

ATA: advanced technology attachement

主机端口的spanning-tree portfast经常被我们忽视，它不仅仅起到加速端口UP速度的目的，对二层网络稳定性也有很重要的作用。

主机端口（以后称host port）的UP，被RSTP视为一种TC（拓扑变化），继而引起MAC表项刷新（删除并重新学习），在重新学习过程中，所有二层单播数据包将被视为未知单播泛洪处理。

最重要的是MAC表项刷新并不只对本设备做刷新，而是对整个二层逻辑网络全部刷新。

也就是如果你在一台二层接入交换机上，接入了一台主机，将触发所有处于同一VLAN内的所有交换机的MAC表项刷新。整个二层网络振荡。

所以建议所有主机端口host port，启用spanning-tree portfast

rationale   基本原理, basic theory

perspective 观点看法, view points, thinking

outset      开始，from the beginning, start

murky       黑暗的，dark, black

neanderthal 穴居人的

swamp       淹没，湿地

reservoirs  水库

cunning     可爱的，狡猾的，精巧的，精心设计的

aroma       香气，浓香

pallet      托盘

fermented   发酵，动乱

yeast       酵母

cholesterol 胆固醇

diabetes    糖尿病

venison     鹿

oxidation&nbs

Link State Tracking in Blade Deployments

刀片服务器两个NIC接口可互为备份，通过teaming实现切换，但teaming只能检测NIC接口或其直连链路状态。

如果刀片内置交换机模块（CISCO）上行链路DOWN，则NIC的切换无法进行。

所以我们需要在交换模块上设置link state tracking配合teaming。

具体配置如下：

link state track 1

int port-channel 1

  uplink to network backbone

  link state group 1 upstream

int g0/1

  description port group member for uplink to network backbone such as 6509

  channel-group 1 mode on

int g0/2

  description port group member for uplink to network backbone such as 6509

  channel-group 1 mode on

int g0/10

  description connected to the blade server NIC

  sw mo ac

&n

Version ! Header Length ! Type of Service ! Total Length !

Identification ! Flags ! Fragmentation Offset

Time to Live ! Protocol ! Header Checksum

Source IP Address

Destination IP Address

Options(if any) ! Padding

Data ...

The first choice:

vi /etc/inittab

modify the lastline's number '5' to '3'

id:5:initdefault:

run level:

0: halt

1: single user mode

2: multiuser mode, no network(NFS)

3: multiuser mode, have network(NFS)

4: reservable

5: multiuser mode, network(NFS), graphic(X11)

6: restart

for

and

nor

but

or

yet

so

both ... and ...

not only ... but also

either ... or ...

neighther ... nor ...

Both Jhon and George like footable.

You can either stay or go.

He is neither handsome nor rich.

It not only rained but also snowed.

He can't decide whether to go out or stay at home.

He is neither in his office nor in the meeting room.

You will find him either reading a book or sleeping.

She is not only pretty but also intelligent.

He is both rich and generous.

I can't decide whether he a brave or stupid.

He likes both watching movies and listening to music.

Whenever you see him he is either talking or laughing.

Neither you nor i know the answer to that question.

He isn't sure whether to marry Flona or Lee-Anne.

Not only

from ... to ...

from ... until ...

I went to unversity from 2002 to 2008                 PAST

I work from nine to five                              NOW

I will go on holiday from July to Auguest.            FUTURE

until ...

He stayed until Friday.                               PAST

I work until 5pm.                  &n