compression - How much can data be compressed?

Is there a scientific limit to how much data can be compressed?

What I mean is, compression is essentially representing a larger amount of data with a smaller one, such as representing a=abc b=def etc... or you could have a database of larger chunks of data and represent them with a hash, write the hashes on a file, and rebuild it by replacing the hashes with their corresponding data, but here the birthday paradox comes in to play very early, for example, if you wanted to represent two digits with only one digit, one digit has a maximum combination of 10, whereas two digits has a maximum of 100 digits, which means the compression ratio here would be only 10% at best... is there any better way of compressing files?

Some way to store a large database of data combinations, represent them in a file that totals less than the original file, transfer it, and then rebuild it at its destination?

windows 8.1 - Still another “driver_power_state_failure” on Win8.1 (with DUMP)

Continuing from question Yet another "driver_power_state_failure" on Win8.1 (with DUMP)

I followed advices provided, upgrading Nvidia drivers and win8.1, but unfortunately I had another BSOD on the same issue: driver_power_state_failure

Output from WinDbg:

Microsoft (R) Windows Debugger Version 6.3.9600.17298 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.


Loading Dump File [C:\Users\Samuele\Documents\MEMORY_27-04-2015.DMP]
Kernel Bitmap Dump File: Full address space is available


************* Symbol Path validation summary **************
Response                         Time (ms)     Location
Deferred                                       SRV*C:\Windows\symbol_cache*http://msdl.microsoft.com/download/symbols
Symbol search path is: SRV*C:\Windows\symbol_cache*http://msdl.microsoft.com/download/symbols
Executable search path is: 
Windows 8 Kernel Version 9600 MP (8 procs) Free x64
Product: WinNt, suite: TerminalServer SingleUserTS Personal
Built by: 9600.17736.amd64fre.winblue_r9.150322-1500
Machine Name:
Kernel base = 0xfffff801`56872000 PsLoadedModuleList = 0xfffff801`56b4b850
Debug session time: Mon Apr 27 09:29:52.197 2015 (UTC + 2:00)
System Uptime: 0 days 0:19:04.911
Loading Kernel Symbols
...............................................................
................................................................
.............................
Loading User Symbols

Loading unloaded module list
.......
*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************

Use !analyze -v to get detailed debugging information.

BugCheck 9F, {3, ffffe0019a5ce060, ffffd00126a5b960, ffffe0019a5ef010}

Probably caused by : pci.sys

Followup: MachineOwner
---------

4: kd> !analyze -v
*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************

DRIVER_POWER_STATE_FAILURE (9f)
A driver has failed to complete a power IRP within a specific time.
Arguments:
Arg1: 0000000000000003, A device object has been blocking an Irp for too long a time
Arg2: ffffe0019a5ce060, Physical Device Object of the stack
Arg3: ffffd00126a5b960, nt!TRIAGE_9F_POWER on Win7 and higher, otherwise the Functional Device Object of the stack
Arg4: ffffe0019a5ef010, The blocked IRP

Debugging Details:
------------------


OVERLAPPED_MODULE: Address regions for 'srv' and 'IntcDAud.sys' overlap

DRVPOWERSTATE_SUBCODE:  3

IMAGE_NAME:  pci.sys

DEBUG_FLR_IMAGE_TIMESTAMP:  53d0f1d4

MODULE_NAME: pci

FAULTING_MODULE: fffff800a7796000 pci

DEFAULT_BUCKET_ID:  WIN8_DRIVER_FAULT

BUGCHECK_STR:  0x9F

PROCESS_NAME:  System

CURRENT_IRQL:  2

ANALYSIS_VERSION: 6.3.9600.17298 (debuggers(dbg).141024-1500) amd64fre

DPC_STACK_BASE:  FFFFD00126A62FB0

STACK_TEXT:  
ffffd001`26a5b928 fffff801`56a7a782 : 00000000`0000009f 00000000`00000003 ffffe001`9a5ce060 ffffd001`26a5b960 : nt!KeBugCheckEx
ffffd001`26a5b930 fffff801`56a7a6a2 : ffffe001`9a5ef838 00000000`00000001 ffffe001`9a5ef870 fffff801`56916391 : nt!PopIrpWatchdogBugcheck+0xde
ffffd001`26a5b990 fffff801`569182d8 : 00000000`00000000 ffffd001`26a5bae0 00000000`00000001 00000000`00000002 : nt!PopIrpWatchdog+0x32
ffffd001`26a5b9e0 fffff801`569c67ea : ffffd001`2b339180 ffffd001`2b339180 ffffd001`2b3453c0 ffffe001`9e61d080 : nt!KiRetireDpcList+0x4f8
ffffd001`26a5bc60 00000000`00000000 : ffffd001`26a5c000 ffffd001`26a56000 00000000`00000000 00000000`00000000 : nt!KiIdleLoop+0x5a


STACK_COMMAND:  kb

FOLLOWUP_NAME:  MachineOwner

IMAGE_VERSION:  6.3.9600.17238

FAILURE_BUCKET_ID:  0x9F_3_ACPI_IMAGE_pci.sys

BUCKET_ID:  0x9F_3_ACPI_IMAGE_pci.sys

ANALYSIS_SOURCE:  KM

FAILURE_ID_HASH_STRING:  km:0x9f_3_acpi_image_pci.sys

FAILURE_ID_HASH:  {20ddeb92-07eb-ebdc-bd08-44da71ffbd68}

Followup: MachineOwner
---------

4: kd> !analyze -v
*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************

DRIVER_POWER_STATE_FAILURE (9f)
A driver has failed to complete a power IRP within a specific time.
Arguments:
Arg1: 0000000000000003, A device object has been blocking an Irp for too long a time
Arg2: ffffe0019a5ce060, Physical Device Object of the stack
Arg3: ffffd00126a5b960, nt!TRIAGE_9F_POWER on Win7 and higher, otherwise the Functional Device Object of the stack
Arg4: ffffe0019a5ef010, The blocked IRP

Debugging Details:
------------------


OVERLAPPED_MODULE: Address regions for 'srv' and 'IntcDAud.sys' overlap

DRVPOWERSTATE_SUBCODE:  3

IMAGE_NAME:  pci.sys

DEBUG_FLR_IMAGE_TIMESTAMP:  53d0f1d4

MODULE_NAME: pci

FAULTING_MODULE: fffff800a7796000 pci

DEFAULT_BUCKET_ID:  WIN8_DRIVER_FAULT

BUGCHECK_STR:  0x9F

PROCESS_NAME:  System

CURRENT_IRQL:  2

ANALYSIS_VERSION: 6.3.9600.17298 (debuggers(dbg).141024-1500) amd64fre

DPC_STACK_BASE:  FFFFD00126A62FB0

STACK_TEXT:  
ffffd001`26a5b928 fffff801`56a7a782 : 00000000`0000009f 00000000`00000003 ffffe001`9a5ce060 ffffd001`26a5b960 : nt!KeBugCheckEx
ffffd001`26a5b930 fffff801`56a7a6a2 : ffffe001`9a5ef838 00000000`00000001 ffffe001`9a5ef870 fffff801`56916391 : nt!PopIrpWatchdogBugcheck+0xde
ffffd001`26a5b990 fffff801`569182d8 : 00000000`00000000 ffffd001`26a5bae0 00000000`00000001 00000000`00000002 : nt!PopIrpWatchdog+0x32
ffffd001`26a5b9e0 fffff801`569c67ea : ffffd001`2b339180 ffffd001`2b339180 ffffd001`2b3453c0 ffffe001`9e61d080 : nt!KiRetireDpcList+0x4f8
ffffd001`26a5bc60 00000000`00000000 : ffffd001`26a5c000 ffffd001`26a56000 00000000`00000000 00000000`00000000 : nt!KiIdleLoop+0x5a


STACK_COMMAND:  kb

FOLLOWUP_NAME:  MachineOwner

IMAGE_VERSION:  6.3.9600.17238

FAILURE_BUCKET_ID:  0x9F_3_ACPI_IMAGE_pci.sys

BUCKET_ID:  0x9F_3_ACPI_IMAGE_pci.sys

ANALYSIS_SOURCE:  KM

FAILURE_ID_HASH_STRING:  km:0x9f_3_acpi_image_pci.sys

FAILURE_ID_HASH:  {20ddeb92-07eb-ebdc-bd08-44da71ffbd68}

Followup: MachineOwner
---------

Minidump: https://www.dropbox.com/s/q0s3522ojxauyea/042715-24328-01.dmp?dl=0

Answer

This time, the Intel PCI Express x16 Controller (PCI\VEN_8086&DEV_0C01) causes the crash:

  !DevObj           !DrvObj            !DevExt           ObjectName
  ffffe0019a5a3ba0  \Driver\pci        ffffe0019a5a3cf0  InfoMask field not found for _OBJECT_HEADER at ffffe0019a5a3b70

> ffffe0019a5e0900  \Driver\ACPI       ffffe0019a5b6890  
  ffffe0019a5ce060  \Driver\pci        ffffe0019a5ce1b0  Cannot read info offset from nt!ObpInfoMaskToOffset

!DevNode ffffe0019a5e0400 :
  DeviceInst is "PCI\VEN_8086&DEV_0C01&SUBSYS_17BD1043&REV_06\3&11583659&1&08"
  ServiceName is "pci"

In the power settings of Windows, disable the PCI Express power saving and look what happens.

windows 7 - Remove Domain Association; Domain controller no longer exists

I have a Win 7 computer for work. The company was acquired and the original domain controller no longer exists. In fact, we don't use a domain controller at all.

Does having a non-exist domain association on a computer impact performance at all and if so, how do I remove the association.

Answer

To remove the computer from the domain, you'll need access to a local administrator account. This may be as easy as typing .\Administrator in the Username: field at login and pushing enter. If the account is disabled or has a password that you do not know, then you'll need to use some kind of boot CD to gain access to it.

As for the performance issue, it's hard to say. It really depends on how that particular domain was configured and what kind of group policies were applied to the machine. For example, if it's still looking for a user profile on a network share that no longer exists, then yeah, you may run in to some odd behavior or even temporary profiles. Basically you're opening yourself to a lot of unknowns.

I would definitely remove the machine from the domain.

encryption - Does anyone know how to encrypt an existing partition in linux while preserving its data

If I have a partition like /dev/hd1 that is unencrypted and want it to be encrypted, but want to keep everything currently in that partition, how can I do that?

Answer

There does not seem to be an solution to do that in place. Truecrypt offers the system encryption only for windows, dm-crypt overwrites partitions. Your best bet would be to move everything from that partition into a backup with cp -a, create an encrypted partition with luks/dm-crypt and move everything back.

networking - Differences between a modem, a wireless access point and a router

Can anyone explain the differences between a modem, a wireless access point, and a router?

What functions do they share and which functions uniquely characterize them?

Answer

Modem - Box from your ISP that connects to the internet. It actually connects to the phone line or the coaxial cable or whatever physical line you have. It normally has at least an ethernet connection, sometimes a USB as well.

Router - Box that connects to the modem and allows multiple devices to use that internet connection at the same time. It also lets the devices talk to each other (so you can transfer files in your house or whatever). Can be wired, wireless, or both.

Wireless Access Point - Attaches to a router and allows wifi connections to the network.

What would an Outlook 2007 macro to automate Paste Special - Unformatted Text look like?

I'd like to assign a macro in Outlook 2007 to a Toolbar button that would execute the equivalent of these clicks when there is formatted text in the Windows clipboard:

1. Click the Paste icon by the bottom arrow


2. Click the Paste Special link.


3. Click the Unformatted Text link.

I have similar macros in Excel 2007 and Word 2007 but haven't been able to get one to work in Outlook 2007 / VBA. What would the VBA code for such a macro be?

Ubuntu: How to set each workspace to a separate monitor

I have a brand-new t-500 Laptop with docking station, and a Samsung SyncMaster T220 connected to it. The OS is Ubuntu 8.04 LTS.

I would like to set up the workspaces, so that the right one would be shown at the external monitor, and the left one would be displayed on the laptop.

I have tried the advice given here - rearranging the displays at the screen configuration tool, but without success - the laptop screen just shows the upper left corner of the SyncMaster, and the screens just overlap again when I rerun the screen config tool (Called "Screen resolution" in my version).

Any help?

Udi

Answer

perhaps this is what you're looking for: http://ubuntuforums.org/showthread.php?t=826717

Basically, from that thread, I'd edit /etc/X11/xorg.conf, and modify the "Screen" section (add red text):

Section "Screen"
    Identifier "Default Screen"
    Monitor "lcddisp"
    Device "Configured Video Device"
    DefaultDepth 24

    SubSection "Display"
        Virtual 3120 1050
    EndSubSection
EndSection

3120 is the sum of both monitor's resolution width (1680 + 1280), 1050 is the max of the resolution's height (1050 > 800).

Restart X (Ctrl-Alt-Backspace), then go to System > Preferences > Screen Resolutions. From there, you can turn on/off one of your monitor, or turn on both cloned, or turn on both side by side (as in dragging windows from one to another).

The only downside to me is that my Intel 965 has a 3D buffer size of 2048x2048 so 3D Compiz looks weird if I have two monitors in side-by-side mode (3120px is way too big to fit on 2048px buffer).

Read that post for more detail.

Source :http://ubuntuforums.org/archive/index.php/t-888979.html