Archive

Archive for April, 2011

Backing up an iOS device (IPhone, iPAD)

April 25, 2011 1 comment

For those interested to backup the ENTIRE file system for an iOS device, here’s how to do it.

Requirements

  1. Jailbroken phone
  2. OpenSSH installed (via cydia)
  3. DD utility on your pc (linux native)
  4. ssh client on your pc (linux native)
Steps
  1. Make sure you can ping your iphone (Settings -> General -> About to get your phone’s IP Address)
  2. Make sure you can ssh to your iphone (from your pc, type ssh root@[iphone ip])
    If you get a prompt asking you to save some key its alright, just type yes
  3. from your PC, run the following command

    ssh root@[iphone ip] dd if=/dev/rdisk0s1 bs=1M | dd of=ios-root.img
    ssh root@[iphone ip] dd if=/dev/rdisk0s2s1 bs=1M | dd of=ios-user.imgssh root@[iphone ip] – ssh client on pc connects to ssh server on iphone
    dd if=/dev/rdisk0 bs=1M – execute dd command with input file =/dev/rdisk0 and block size of 1M
    | – pipe to redirect input to the next command
    dd of=ios.img – run dd on the pc with output file=ios.img

this command will take a while depending on your iphone and wifi speed

Categories: General

iTunes- QuickTime was not found

April 15, 2011 4 comments

If you are running iTunes 64bit on a 64bit os (e.g windows 7) you may encounter “QuickTime was not found” error

To fix this

Go to C:\Program Files (x86)\QuickTime\QTSystem and copy QTCF.dll to C:\Windows\SysWOW64

Categories: Uncategorized

Windows 2008 R2 DFS doesn’t seem to use all the bandwidth available

April 14, 2011 2 comments

If you have just created a DFS replication between 2 machines, it should start replicating. However you will notice that the replication is extremely slow and usually does not take up too much of the available bandwidth, epecially in an intranet environment.

What happens is in Windows Server 2008 R2, by default DFS replication turns on remote differential compression (rdc). What RDC does is to just send delta changes from the source to destination servers.

This works great if you

  1. are paying for bandwidth
  2. have a low bandwidth pipe to do the transfer
  3. have large files
  4. Have ample CPU, Ram, Disk

 

But its crap when

  1. there are lots of small files
  2. the link is a strong pipe (e.g intranet environment)
  3. Don’t have so much CPU, Ram, Disk or those can be better utilized (delta changes takes up cycles and space)

 

So what you can do, if you do not want to enable RDC?

  1. Start up DFS management
  2. Select the replication that you want to modify
  3. Click on the connections tab
  4. Select the connections in questions (multiple selection is possible)
  5. Right click, properties
  6. Uncheck “Use remote differential compression (RDC)”
  7. Click ok

And the next thing you know, DFS will start gobbling up your bandwidth to send all the files over asap!

Categories: Performance