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  • Catch AutoVue at the COE 2010 PLM Conference

    - by [email protected]
    It's a busy tradeshow season! The AutoVue team will be exhibiting at next week's COE 2010 PLM Conference and Technifair in Las Vegas, NV. This will be a unique opportunity to meet with AutoVue visualization experts and discuss how to leverage visualization throughout your engineering organization to capitalize on product and engineering information to improve business processes, such as design reviews, change management and design revisions. If you plan on attending, be sure to stop by Oracle's AutoVue booth (#508). Click here for more details about the show.

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  • wifi hardware switch doesn't work on a Dell 1018

    - by user42566
    I have a problem with my Dell 1018 Inspiron. I can't switch the wifi on, through the key on the keyboard. I think it's a driver problem since Ubuntu 11.10. This are the versions i tried: Ubuntu 10.04 / 10.10 It's possible to install the driver by hand: sudo add-apt-repository ppa:lexical/hwe-wireless sudo apt-get update sudo apt-get install rtl8192ce-dkms Ubuntu 11.04 It works out of the box Ubuntu 11.10 / 12.04 I haven’t found any solution for these versions. The "ppa:lexical/hwe-wireless" doesn't work for these versions. It says Can not find package rtl8192ce-dkms. The window of additional drivers is empty. So I can't install the driver. The wired network works good. Here is some information: 0: dell-wifi: Wireless LAN Soft blocked: no Hard blocked: no 1: phy0: Wireless LAN Soft blocked: no Hard blocked: yes sudo lshw -class network *-network description: Ethernet interface product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:05:00.0 logical name: eth0 version: 05 serial: 5c:26:0a:0d:20:10 size: 10Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half firmware=rtl_nic/rtl8105e-1.fw latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:43 ioport:2000(size=256) memory:f0f2c000-f0f2cfff memory:f0f18000-f0f1bfff *-network description: Wireless interface product: RTL8188CE 802.11b/g/n WiFi Adapter vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:07:00.0 logical name: wlan0 version: 01 serial: 70:f1:a1:fe:15:bd width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=rtl8192ce driverversion=3.2.0-22-generic-pae firmware=N/A ip=192.168.1.76 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn resources: irq:17 ioport:3000(size=256) memory:f0100000-f0103fff mark@mark-Inspiron-1018:~$ mark@mark-Inspiron-1018:~$ sudo lspci -nn 00:00.0 Host bridge [0600]: Intel Corporation N10 Family DMI Bridge [8086:a010] 00:02.0 VGA compatible controller [0300]: Intel Corporation N10 Family Integrated Graphics Controller [8086:a011] 00:02.1 Display controller [0380]: Intel Corporation N10 Family Integrated Graphics Controller [8086:a012] 00:1b.0 Audio device [0403]: Intel Corporation N10/ICH 7 Family High Definition Audio Controller [8086:27d8] (rev 02) 00:1c.0 PCI bridge [0604]: Intel Corporation N10/ICH 7 Family PCI Express Port 1 [8086:27d0] (rev 02) 00:1c.1 PCI bridge [0604]: Intel Corporation N10/ICH 7 Family PCI Express Port 2 [8086:27d2] (rev 02) 00:1d.0 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #1 [8086:27c8] (rev 02) 00:1d.1 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 [8086:27c9] (rev 02) 00:1d.2 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 [8086:27ca] (rev 02) 00:1d.3 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 [8086:27cb] (rev 02) 00:1d.7 USB controller [0c03]: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller [8086:27cc] (rev 02) 00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:2448] (rev e2) 00:1f.0 ISA bridge [0601]: Intel Corporation NM10 Family LPC Controller [8086:27bc] (rev 02) 00:1f.2 SATA controller [0106]: Intel Corporation N10/ICH7 Family SATA Controller [AHCI mode] [8086:27c1] (rev 02) 00:1f.3 SMBus [0c05]: Intel Corporation N10/ICH 7 Family SMBus Controller [8086:27da] (rev 02) 05:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller [10ec:8136] (rev 05) 07:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8188CE 802.11b/g/n WiFi Adapter [10ec:8176] (rev 01) mark@mark-Inspiron-1018:~$ mark@mark-Inspiron-1018:~$ lsusb Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 001 Device 002: ID 174f:1127 Syntek mark@mark-Inspiron-1018:~$

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  • Abstraction, Politics, and Software Architecture

    Abstraction can be defined as a general concept and/or idea that lack any concrete details. Throughout history this type of thinking has led to an array of new ideas and innovations as well as increased confusion and conspiracy. If one was to look back at our history they will see that abstraction has been used in various forms throughout our past. When I was growing up I do not know how many times I heard politicians say “Leave no child left behind” or “No child left behind” as a major part of their campaign rhetoric in regards to a stance on education. As you can see their slogan is a perfect example of abstraction because it only offers a very general concept about improving our education system but they do not mention how they would like to do it. If they did then they would be adding concrete details to their abstraction thus turning it in to an actual working plan as to how we as a society can help children succeed in school and in life, but then they would not be using abstraction. By now I sure you are thinking what does abstraction have to do with software architecture. You are valid in thinking this way, but abstraction is a wonderful tool used in information technology especially in the world of software architecture. Abstraction is one method of extracting the concepts of an idea so that it can be understood and discussed by others of varying technical abilities and backgrounds. One ways in which I tend to extract my architectural design thoughts is through the use of basic diagrams to convey an idea for a system or a new feature for an existing application. This allows me to generically model an architectural design through the use of views and Unified Markup Language (UML). UML is a standard method for creating a 4+1 Architectural View Models. The 4+1 Architectural View Model consists of 4 views typically created with UML as well as a general description of the concept that is being expressed by a model. The 4+1 Architectural View Model: Logical View: Models a system’s end-user functionality. Development View: Models a system as a collection of components and connectors to illustrate how it is intended to be developed.  Process View: Models the interaction between system components and connectors as to indicate the activities of a system. Physical View: Models the placement of the collection of components and connectors of a system within a physical environment. Recently I had to use the concept of abstraction to express an idea for implementing a new security framework on an existing website. My concept would add session based management in order to properly secure and allow page access based on valid user credentials and last user activity.  I created a basic Process View by using UML diagrams to communicate the basic process flow of my changes in the application so that all of the projects stakeholders would be able to understand my idea. Additionally I created a Logical View on a whiteboard while conveying the process workflow with a few stakeholders to show how end-user will be affected by the new framework and gaining additional input about the design. After my Logical and Process Views were accepted I then started on creating a more detailed Development View in order to map how the system will be built based on the concept of components and connections based on the previously defined interactions. I really did not need to create a Physical view for this idea because we were updating an existing system that was already deployed based on an existing Physical View. What do you think about the use of abstraction in the development of software architecture? Please let me know.

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  • SQL Down Under Podcast 50 - Guest Louis Davidson now online

    - by Greg Low
    Hi Folks,I've recorded an interview today with SQL Server MVP Louis Davidson. In it, Louis discusses some of his thoughts on database design and his latest book.You'll find the podcast here: http://www.sqldownunder.com/Resources/Podcast.aspxAnd you'll find his latest book (Pro SQL Server 2012 Relational Database Design and Implementation) here: http://www.amazon.com/Server-Relational-Database-Implementation-Professional/dp/1430236957/ref=sr_1_2?ie=UTF8&qid=1344997477&sr=8-2&keywords=louis+davidsonEnjoy!

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  • what's included in a typical computer architecture class? [closed]

    - by sq1020
    Does this description fit what's usually included in a computer architecture class? Computer Organization and Assembly Language An introduction to the hardware organization and assembly language of the Intel processor. Topics include memory hierarchy and design- CPU design- pipelining- addressing modes- subroutine linkage- polled input/output- interrupts- high level language interfacing and macros.

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  • What are the advantages and disadvantages of having a subdomain for each user account?

    - by Sathish Manohar
    I notice two types of design used in web applications, some with a particular subdomain for users contents, and some with same URL structure for all the accounts. Ex: unique.domain.com and another_unique.domain.com for subdomains for sites like blogspot, wordpress, basecamp etc. while in the other approach domain.com/action1 and domain.com/action2 the content is shown according to the user logged in, but the URL is same for every user. What are main differences between both of these kind of design?

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  • Turning your code inside out (functional style) compared to a OO paradigm

    - by Acaz Souza
    I have find this article Turning Your Code Inside Out and I want to know how this approach described in article is for OO programmers/languages. Is this style of design used in OO programmers/languages? What's downsides and goodsides of this approach in a OO language? Update: OO objects have state and behavior, the design explained in article is stateless. Is not only Single Responsability Principle. (If I'm talking shit, please explain to me instead of only downside/close votes)

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  • Hardware wireless switch has no effect after suspend and 13.10 upgrade

    - by blaineh
    This seems to be a fairly chronic problem, as shown by the following questions: How do I fix a "Wireless is disabled by hardware switch" error? Wireless disabled by hardware switch "Wireless disabled by hardware switch" after suspend and other hardware buttons ineffective - how can I solve this? but no good solutions have been found! Wireless works fine after a reboot, but after a suspend the hardware switch (for my laptop this is f12) has no effect on the wireless, it is just permanently off, and shows that it is with a red LED. All My rfkill list all reads: 0: phy0: Wireless LAN Soft blocked: no Hard blocked: yes 1: hp-wifi: Wireless LAN Soft blocked: no Hard blocked: yes Any combination with rfkill <un>block wifi doesn't work, although one time first blocking then unblocking actually turned it on again. sudo lshw -C network reads: *-network DISABLED description: Wireless interface product: AR9285 Wireless Network Adapter (PCI-Express) vendor: Qualcomm Atheros physical id: 0 bus info: pci@0000:02:00.0 logical name: wlan0 version: 01 serial: 78:e4:00:65:2e:3f width: 64 bits clock: 33MHz capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless configuration: broadcast=yes driver=ath9k driverversion=3.11.0-12-generic firmware=N/A ip=155.99.215.79 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn resources: irq:17 memory:90100000-9010ffff *-network DISABLED description: Ethernet interface product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:03:00.0 logical name: eth0 version: 02 serial: c8:0a:a9:89:b4:30 size: 10Mbit/s capacity: 100Mbit/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10Mbit/s resources: irq:42 ioport:2000(size=256) memory:90010000-90010fff memory:90000000-9000ffff memory:90020000-9002ffff Also, adding a /etc/pm/sleep.d/brcm.sh file as recommended here simply prevents the laptop from suspending at all, which of course is no good. This question has an answer urging to install the original driver, but it wasn't an "accepted answer" so I'd rather not take a chance on it. Also I'll admit I'm a bit lost on that and would like help doing so with the specific information I've given. xev shows that no internal event is triggered for my wireless switch (f12), but other function keys also acting as hardware switches work fine. I would be happy to provide more information, so long as you're willing to help me find it for you! This is a very annoying bug. I have a Compaq Presario CQ62. Edit. I just tried to reload bios defaults (or something) as shown by this video. Didn't work. Edit. I tried the contents of this answer, and it didn't work. Edit. I made a pastebin of dmesg. I couldn't even begin to understand the contents. Edit. Output of lspci | grep Network: 02:00.0 Network controller: Qualcomm Atheros AR9285 Wireless Network Adapter (PCI-Express) (rev 01)

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  • Errors when trying to compile the driver for the rtl8192su wireless adapter

    - by Tom Brito
    I have a wireless to usb adapter, and I'm having some trouble to install the drivers on Ubuntu. First of all, the readme says to use the make command, and I already got errors: $ make make[1]: Entering directory `/usr/src/linux-headers-2.6.35-22-generic' CC [M] /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c: In function ‘rtl8192_usb_probe’: /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12325: error: ‘struct net_device’ has no member named ‘open’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12326: error: ‘struct net_device’ has no member named ‘stop’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12327: error: ‘struct net_device’ has no member named ‘tx_timeout’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12328: error: ‘struct net_device’ has no member named ‘do_ioctl’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12329: error: ‘struct net_device’ has no member named ‘set_multicast_list’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12330: error: ‘struct net_device’ has no member named ‘set_mac_address’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12331: error: ‘struct net_device’ has no member named ‘get_stats’ /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.c:12332: error: ‘struct net_device’ has no member named ‘hard_start_xmit’ make[2]: *** [/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u/r8192U_core.o] Error 1 make[1]: *** [_module_/home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/HAL/rtl8192u] Error 2 make[1]: Leaving directory `/usr/src/linux-headers-2.6.35-22-generic' make: *** [all] Error 2 /home/wellington/Desktop/rtl8192su_linux_2.4_2.6.0003.0301.2010/ is the path where I copied the drivers on my computer. Any idea how to solve this? (I don't even know what the error is...) update: sudo lshw -class network *-network description: Ethernet interface product: RTL8111/8168B PCI Express Gigabit Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:01:00.0 logical name: eth0 version: 03 serial: 78:e3:b5:e7:5f:6e size: 10MB/s capacity: 1GB/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list rom ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=half latency=0 link=no multicast=yes port=MII speed=10MB/s resources: irq:42 ioport:d800(size=256) memory:fbeff000-fbefffff memory:faffc000-faffffff memory:fbec0000-fbedffff *-network DISABLED description: Wireless interface physical id: 2 logical name: wlan0 serial: 00:26:18:a1:ae:64 capabilities: ethernet physical wireless configuration: broadcast=yes multicast=yes wireless=802.11b/g sudo lspci 00:00.0 Host bridge: Intel Corporation Core Processor DRAM Controller (rev 18) 00:02.0 VGA compatible controller: Intel Corporation Core Processor Integrated Graphics Controller (rev 18) 00:16.0 Communication controller: Intel Corporation 5 Series/3400 Series Chipset HECI Controller (rev 06) 00:1a.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06) 00:1b.0 Audio device: Intel Corporation 5 Series/3400 Series Chipset High Definition Audio (rev 06) 00:1c.0 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 1 (rev 06) 00:1c.2 PCI bridge: Intel Corporation 5 Series/3400 Series Chipset PCI Express Root Port 3 (rev 06) 00:1d.0 USB Controller: Intel Corporation 5 Series/3400 Series Chipset USB2 Enhanced Host Controller (rev 06) 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev a6) 00:1f.0 ISA bridge: Intel Corporation 5 Series Chipset LPC Interface Controller (rev 06) 00:1f.2 SATA controller: Intel Corporation 5 Series/3400 Series Chipset 6 port SATA AHCI Controller (rev 06) 00:1f.3 SMBus: Intel Corporation 5 Series/3400 Series Chipset SMBus Controller (rev 06) 01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) 02:00.0 FireWire (IEEE 1394): VIA Technologies, Inc. VT6315 Series Firewire Controller (rev 01) sudo lsusb Bus 002 Device 003: ID 0bda:0158 Realtek Semiconductor Corp. USB 2.0 multicard reader Bus 002 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 001 Device 004: ID 045e:00f9 Microsoft Corp. Wireless Desktop Receiver 3.1 Bus 001 Device 003: ID 0b05:1786 ASUSTek Computer, Inc. Bus 001 Device 002: ID 8087:0020 Intel Corp. Integrated Rate Matching Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

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  • PSD to WordPress Theme Coding

    About PSD. The files and documents that are made by using the application Adobe Photoshop are saved with the extension of .PSD. PSD stands for Photoshop Document. The .PSD file design can be exporte... [Author: Jenna Bethshaya - Web Design and Development - May 25, 2010]

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  • Professional Bespoke Web Development Firm

    Now those who are looking forward to having professional bespoke web design services on board, they need not go and look any further. This is because of the fact that such firms are available all aro... [Author: John Anthony - Web Design and Development - May 18, 2010]

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  • Organization &amp; Architecture UNISA Studies &ndash; Chap 6

    - by MarkPearl
    Learning Outcomes Discuss the physical characteristics of magnetic disks Describe how data is organized and accessed on a magnetic disk Discuss the parameters that play a role in the performance of magnetic disks Describe different optical memory devices Magnetic Disk The way data is stored on and retried from magnetic disks Data is recorded on and later retrieved form the disk via a conducting coil named the head (in many systems there are two heads) The writ mechanism exploits the fact that electricity flowing through a coil produces a magnetic field. Electric pulses are sent to the write head, and the resulting magnetic patterns are recorded on the surface below with different patterns for positive and negative currents The physical characteristics of a magnetic disk   Summarize from book   The factors that play a role in the performance of a disk Seek time – the time it takes to position the head at the track Rotational delay / latency – the time it takes for the beginning of the sector to reach the head Access time – the sum of the seek time and rotational delay Transfer time – the time it takes to transfer data RAID The rate of improvement in secondary storage performance has been considerably less than the rate for processors and main memory. Thus secondary storage has become a bit of a bottleneck. RAID works on the concept that if one disk can be pushed so far, additional gains in performance are to be had by using multiple parallel components. Points to note about RAID… RAID is a set of physical disk drives viewed by the operating system as a single logical drive Data is distributed across the physical drives of an array in a scheme known as striping Redundant disk capacity is used to store parity information, which guarantees data recoverability in case of a disk failure (not supported by RAID 0 or RAID 1) Interesting to note that the increase in the number of drives, increases the probability of failure. To compensate for this decreased reliability RAID makes use of stored parity information that enables the recovery of data lost due to a disk failure.   The RAID scheme consists of 7 levels…   Category Level Description Disks Required Data Availability Large I/O Data Transfer Capacity Small I/O Request Rate Striping 0 Non Redundant N Lower than single disk Very high Very high for both read and write Mirroring 1 Mirrored 2N Higher than RAID 2 – 5 but lower than RAID 6 Higher than single disk Up to twice that of a signle disk for read Parallel Access 2 Redundant via Hamming Code N + m Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Parallel Access 3 Bit interleaved parity N + 1 Much higher than single disk Highest of all listed alternatives Approximately twice that of a single disk Independent Access 4 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, significantly lower than single disk for write Similar to RAID 0 for read, significantly lower than single disk for write Independent Access 5 Block interleaved parity N + 1 Much higher than single disk Similar to RAID 0 for read, lower than single disk for write Similar to RAID 0 for read, generally  lower than single disk for write Independent Access 6 Block interleaved parity N + 2 Highest of all listed alternatives Similar to RAID 0 for read; lower than RAID 5 for write Similar to RAID 0 for read, significantly lower than RAID 5  for write   Read page 215 – 221 for detailed explanation on RAID levels Optical Memory There are a variety of optical-disk systems available. Read through the table on page 222 – 223 Some of the devices include… CD CD-ROM CD-R CD-RW DVD DVD-R DVD-RW Blue-Ray DVD Magnetic Tape Most modern systems use serial recording – data is lade out as a sequence of bits along each track. The typical recording used in serial is referred to as serpentine recording. In this technique when data is being recorded, the first set of bits is recorded along the whole length of the tape. When the end of the tape is reached the heads are repostioned to record a new track, and the tape is again recorded on its whole length, this time in the opposite direction. That process continued back and forth until the tape is full. To increase speed, the read-write head is capable of reading and writing a number of adjacent tracks simultaneously. Data is still recorded serially along individual tracks, but blocks in sequence are stored on adjacent tracks as suggested. A tape drive is a sequential access device. Magnetic tape was the first kind of secondary memory. It is still widely used as the lowest-cost, slowest speed member of the memory hierarchy.

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  • Google I/O 2010 - A JIT Compiler for Android's Dalvik VM

    Google I/O 2010 - A JIT Compiler for Android's Dalvik VM Google I/O 2010 - A JIT Compiler for Android's Dalvik VM Android 301 Ben Cheng, Bill Buzbee In this session we will outline the design of a JIT Compiler suitable for embedded Android devices. Topics will include an architectural overview, the rationale for design decisions and the special support for JIT verification, testing and tuning. For all I/O 2010 sessions, please go to code.google.com From: GoogleDevelopers Views: 3 0 ratings Time: 01:00:14 More in Science & Technology

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  • Enterprise Service Bus (ESB): Important architectural piece to a SOA or is it just vendor hype?

    Is an Enterprise Service Bus (ESB) an important architectural piece to a Service-Oriented Architecture (SOA), or is it just vendor hype in order to sell a particular product such as SOA-in-a-box? According to IBM.com, an ESB is a flexible connectivity infrastructure for integrating applications and services; it offers a flexible and manageable approach to service-oriented architecture implementation. With this being said, it is my personal belief that ESBs are an important architectural piece to any SOA. Additionally, generic design patterns have been created around the integration of web services in to ESB regardless of any vendor. ESB design patterns, according to Philip Hartman, can be classified in to the following categories: Interaction Patterns: Enable service interaction points to send and/or receive messages from the bus Mediation Patterns: Enable the altering of message exchanges Deployment Patterns: Support solution deployment into a federated infrastructure Examples of Interaction Patterns: One-Way Message Synchronous Interaction Asynchronous Interaction Asynchronous Interaction with Timeout Asynchronous Interaction with a Notification Timer One Request, Multiple Responses One Request, One of Two Possible Responses One Request, a Mandatory Response, and an Optional Response Partial Processing Multiple Application Interactions Benefits of the Mediation Pattern: Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently Design an intermediary to decouple many peers Promote the many-to-many relationships between interacting peers to “full object status” Examples of Interaction Patterns: Global ESB: Services share a single namespace and all service providers are visible to every service requester across an entire network Directly Connected ESB: Global service registry that enables independent ESB installations to be visible Brokered ESB: Bridges services that are reluctant to expose requesters or providers to ESBs in other domains Federated ESB: Service consumers and providers connect to the master or to a dependent ESB to access services throughout the network References: Mediator Design Pattern. (2011). Retrieved 2011, from SourceMaking.com: http://sourcemaking.com/design_patterns/mediator Hartman, P. (2006, 24 1). ESB Patterns that "Click". Retrieved 2011, from The Art and Science of Being an IT Architect: http://artsciita.blogspot.com/2006/01/esb-patterns-that-click.html IBM. (2011). WebSphere DataPower XC10 Appliance Version 2.0. Retrieved 2011, from IBM.com: http://publib.boulder.ibm.com/infocenter/wdpxc/v2r0/index.jsp?topic=%2Fcom.ibm.websphere.help.glossary.doc%2Ftopics%2Fglossary.html Oracle. (2005). 12 Interaction Patterns. Retrieved 2011, from Oracle® BPEL Process Manager Developer's Guide: http://docs.oracle.com/cd/B31017_01/integrate.1013/b28981/interact.htm#BABHHEHD

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  • How to use more than 3 virtual disks in Linux using CentOS and XenServer

    - by 010110110101
    I've attached 5 virtual disks to a Virtual Machine in Citrix XenServer. The VM has the xs-tools installed. Initially it said that it couldn't add so many disks. After I installed the xs-tools, it let me add all the disks. But /dev doesn't show all the disks. It shows these: /dev/xvda /dev/xvdb /dev/xvdc /dev/cdrom Perhaps it is bound by the limits of an IDE bus? (3 disks + CD-ROM) If so, how does one change the VM to use SCSI? Edit: According to the documentation: 2.6.3. VM Block Devices In the PV Linux case, block devices are passed through as PV devices. XenServer does not attempt to emulate SCSI or IDE, but instead provides a more suitable interface in the virtual environment in the form of xvd* devices. It is also possible to get an sd* device using the same mechanism, where the PV driver inside the VM takes over the SCSI device namespace. This is not desirable so it is best to use xvd* where possible for PV guests (this is the default for Debian and RHEL). For Windows or other fully virtualized guests, XenServer emulates an IDE bus in the form of an hd* device. When using Windows, installing the Citrix Tools for Virtual Machines installs a special PV driver that works in a similar way to Linux, except in the fully virtualized environment. Still, with 5 virtual disks attached, I don't see the other xvd devices. Edit #2: (attached requested info) Host Machine: XenServer 6.1 Linux version 2.6.32.43-0.4.1.xs1.6.10.777.170770xen (geeko@buildhost) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-51)) #1 SMP Wed Apr 17 05:52:03 EDT 2013 Guest Machine: CentOS release 6.4 (Final) Linux version 2.6.32-358.6.2.el6.x86_64 ([email protected]) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-3) (GCC) ) #1 SMP Thu May 16 20:59:36 UTC 2013 Output of 'fdisk -l' on Guest Machine: Note, the disk beyond the first 3 attached are not displaying -- there should be 4 100GB disks. (There are a total of 5 disks displayed in XenCenter -- 16GB, 100GB, 100GB, 100GB, 100GB) Disk /dev/xvdb: 107.4 GB, 107374182400 bytes 255 heads, 63 sectors/track, 13054 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xfb6c95b9 Device Boot Start End Blocks Id System /dev/xvdb1 1 13054 104856223+ 83 Linux Disk /dev/xvda: 17.2 GB, 17179869184 bytes 255 heads, 63 sectors/track, 2088 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000e5f41 Device Boot Start End Blocks Id System /dev/xvda1 * 1 64 512000 83 Linux Partition 1 does not end on cylinder boundary. /dev/xvda2 64 2089 16264192 8e Linux LVM Disk /dev/xvdc: 107.4 GB, 107374182400 bytes 255 heads, 63 sectors/track, 13054 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xed249ced Device Boot Start End Blocks Id System /dev/xvdc1 1 13054 104856223+ 83 Linux Disk /dev/mapper/vg_blue-lv_root: 14.6 GB, 14571012096 bytes 255 heads, 63 sectors/track, 1771 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Disk /dev/mapper/vg_blue-lv_swap: 2080 MB, 2080374784 bytes 255 heads, 63 sectors/track, 252 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 I see that the Linux versions say SMP. The Guest VM doesn't say "xen" in the name. However, I have already run yum install kernel-xen. Could be a clue?

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  • Pay in the future should make you think in the present

    - by BuckWoody
    Distributed Computing - and more importantly “-as-a-Service” models of computing have a different cost model. This is something that sounds obvious on the surface but it’s often forgotten during the design and coding phase of a project. In on-premises computing, we’re used to purchasing a server and all of the hardware infrastructure and software licenses needed not only for one project, but several. This is an up-front or “sunk” cost that we consume by running code the organization needs to perform its function. Using a direct connection over wires you’ve already paid for, we don’t often have to think about bandwidth, hits on the data store or the amount of compute we use - we just know more is better. In a pay-as-you-go model, however, each of these architecture decisions has a potential cost impact. The amount of data you store, the number of times you access it, and the amount you send back all come with a charge. The offset is that you don’t buy anything at all up-front, so that sunk cost is freed up. And financial professionals know that money now is worth more than money later. Saving that up-front cost allows you to invest it in other things. It’s not just that you’re using things that now cost money - it’s that the design itself in distributed computing has a cost impact. That can be a really good thing, such as when you dynamically add capacity for paying customers. If you can tie back the cost of a series of clicks to what a user will pay to do so, you can set a profit margin that is easy to track. Here’s a case in point: Assume you are using a large instance in Windows Azure to compute some data that you retrieve from a SQL Azure database. If you don’t monitor the path of the application, you may not know what you are really using. Since you’re paying by the size of the instance, it’s best to maximize it all the time. Recently I evaluated just this situation, and found that downsizing the instance and adding another one where needed, adding a caching function to the application, moving part of the data into Windows Azure tables not only increased the speed of the application, but reduced the cost and more closely tied the cost to the profit. The key is this: from the very outset - the design - make sure you include metrics to measure for the cost/performance (sometimes these are the same) for your application. Windows Azure opens up awesome new ways of doing things, so make sure you study distributed systems architecture before you try and force in the application design you have on premises into your new application structure.

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  • lvm disappeared after disc replacement on raid10

    - by user142295
    here my problem: I am running ubuntu 12.04 on a raid10 (4 disks), on top of which I installed an lvm with two volume groups (one for /, one for /home). The layout of the disks are as follows: Disk /dev/sda: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0003f3b6 Device Boot Start End Blocks Id System /dev/sda1 * 63 481949 240943+ 83 Linux /dev/sda2 481950 2910640634 1455079342+ fd Linux raid autodetect /dev/sda3 2910640635 2930272064 9815715 82 Linux swap / Solaris Disk /dev/sdb: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00069785 Device Boot Start End Blocks Id System /dev/sdb1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdb2 2910158685 2930272064 10056690 82 Linux swap / Solaris Disk /dev/sdc: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdc1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdc2 2910158685 2930272064 10056690 82 Linux swap / Solaris Disk /dev/sdd: 1500.3 GB, 1500301910016 bytes 255 heads, 63 sectors/track, 182401 cylinders, total 2930277168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000f14de Device Boot Start End Blocks Id System /dev/sdd1 63 2910158684 1455079311 fd Linux raid autodetect /dev/sdd2 2910158685 2930272064 10056690 82 Linux swap / Solaris The first disk (/dev/sda) contains the /boot partition on /dev/sda1. I use grub2 to boot the system off this partition. On top of this raid10 I installed two volume groups, one for /, one for /home. This system worked well, I even exchanged two disks during the last two years. It always worked. But not this time. For the first time, /dev/sda broke. I do not know if this is an issue – I know I would have struggled anyways to overcome the problem with /boot installed on that disk and grub2 installed on the mbr of /dev/sda. Anyways, I did what I always did: start knoppix fire up the raid sudo mdadm --examine -scan which returns ARRAY /dev/md127 UUID=0dbf4558:1a943464:132783e8:19cdff95 start it up sudo mdadm --assemble /dev/md127 fail the failing disk (smart event) sudo mdadm /dev/md127 --fail /dev/sda2 remove the failing disk sudo mdadm /dev/md127 --remove /dev/sda2 stop the raid sudo mdadm -S /dev/md127 take out the disk replace it with a new one create the same partitions as on the failling one add it to the raid sudo mdadm --assemble /dev/md127 sudo mdadm /dev/md127 --add /dev/sda2 wait 4 hours All looks fine: cat /proc/mdstat returns: Personalities : [raid10] md127 : active raid10 sda2[0] sdd1[3] sdc1[2] sdb1[1] 2910158464 blocks 64K chunks 2 near-copies [4/4] [UUUU] unused devices: <none> and sudo mdadm --detail /dev/md127 returns /dev/md127: Version : 0.90 Creation Time : Wed Jun 10 13:08:46 2009 Raid Level : raid10 Array Size : 2910158464 (2775.34 GiB 2980.00 GB) Used Dev Size : 1455079232 (1387.67 GiB 1490.00 GB) Raid Devices : 4 Total Devices : 4 Preferred Minor : 127 Persistence : Superblock is persistent Update Time : Thu Mar 21 16:27:40 2013 State : clean Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : near=2 Chunk Size : 64K UUID : 0dbf4558:1a943464:132783e8:19cdff95 (local to host Microknoppix) Events : 0.4824680 Number Major Minor RaidDevice State 0 8 2 0 active sync /dev/sda2 1 8 17 1 active sync /dev/sdb1 2 8 33 2 active sync /dev/sdc1 3 8 49 3 active sync /dev/sdd1 However, there is no trace of the volume groups. Rebooting into knoppix does not help Restarting the old system (I actually replugged and re-added the failing disk for that – the system begins to start, but then fails to see the / partition – no wonder if the volume group is gone) does not help. sudo vgscan, sudo vgdisplay, sudo lvs, sudo lvdisplay, sudo vgscan –mknodes all returned No volume groups found. I am completely at a loss. Can anyone tell me if and how I can recover my data? Thanks in advance!

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