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Fixing error code 43 connecting Andriod phone

Posted by: martinl | July 19, 2014 Comments Off |

In order to root my ZOPO android phone, I installed the MTK usb driver on Windows 8.1. After instalation, it caused error code 43 whenever any android phone was plugged in the system. Same problem even after I removed the driver using pnputil and reboot.

Initial research suggested to perform PC refresh which would remove all desktop apps. Luckily, with some patient, I found and followed this to uninstall the usb root hub driver and bingo!

under: sysadmin, windows
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Add-Computer cmdlet requires Delete privilege

Posted by: martinl | April 24, 2014 Comments Off |

I’ve an account for joining computer to AD using sysprep. My colleague tried to use the account with the Add-Computer cmdlet but received access denied. It’s found that “Delete” privilege is needed for the cmdlet, though, the computer account is not deleted! Thanks Google and those willing to share!

under: sysadmin
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Determine Exchange server version from Outlook

Posted by: martinl | April 3, 2014 Comments Off |

When reviewing load-balancing requirement of our Exchange Server, I need to determine the version of Exchange. It’s simple but a hidden feature of Outlook,

http://office.microsoft.com/en-us/outlook-help/determine-the-version-of-microsoft-exchange-server-my-account-connects-to-HA010117038.aspx

under: application
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A major problem with Microsoft VDI is that there is no free RDP client for Mac. Neither Microsoft RDP for Mac v2.1.1 nor CoRD v0.5.7 support RDC redirection/gateway.

I’ve tried freeRDP half-year ago. At that time, I’ve to build it from source and it’s not mature enough for end-user. Today, the installation is a bit easier. It can be installed from package manager with a couple of steps,

  1. Install Xcode from AppStore
  2. Install Xcode Command Line Tools from Xcode->Preferences->Downloads
  3. Install port pkg from MacPorts.org
  4. Install FreeRDP from a terminal shell
It seems to be more stable but still not good enough for average users. For example, it doesn’t works with RDP gateway and there are reports on mouse and other stability problems in the forum.
iTap
iTap seems to be the most common commercial alternative. It costs about HK$200. It works well with Remote Desktop Gateway. There is even a post mentioned it supports Microsoft VDI but I can’t find a way to specify desktop pool ID.
Wise PocketCloud Pro
It’s cheaper than iTap and costs only HK$116. The free version is quite good but doesn’t support RDP Gateway. So, I haven’t tried it yet.
under: sysadmin, virtualisation
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A bit of NFS Security

Posted by: martinl | April 26, 2013 | No Comment |

Spent a day on studying NFS. Here are some recommended NFS security measures,

  1. Tighten access with tcpwrapper, i.e. hosts.allow and hosts.deny, and firewall.
  2. Export with the root_squash flag.
  3. All important binaries and files on server should be owned by root, and not bin or other non-root account (so root_squash can protect them).
  4. Export with the secure flag so malicious user on client machine can’t setup spoofing connection to the server.
  5. Mount with nosuid flag
  6. Tunnel NFS over ssh
http://nfs.sourceforge.net/nfs-howto/ar01s06.html
under: computer security, sysadmin
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After kernel upgrade of a CentOS 5.9 x64 NFS server, Apache web server on a Solaris 8 NFS client is unable to generate directory index for files on a NFS share. No problem if the NFS client is a CentOS 5.9 x86 client with kernel 2.6.18-348.3.1. Both NFS clients are using NFS3 protocol.

Downgrading the kernel of the NFS server from 2.6.18-348.4.1 to 2.6.18-308 have the problem fixed. It looks like the problem is related to the bug below,

http://bugs.centos.org/view.php?id=6246

under: application, sysadmin
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Disable Smart Card Sharing

Posted by: martinl | January 25, 2013 | No Comment |

The ability to share smart card reader among VM is supposed to be a good thing. But the implementation in VMware workstation 8 seems imperfect. With the virtual reader enabled, my smartcard application frequently failed to access to the smartcard. Fortunately, you may disable the sharing by modifying the config file at,

C:\ProgramData\VMware\VMware Workstation\config.ini

More info,

http://pubs.vmware.com/workstation-9/index.jsp?topic=/com.vmware.ws.using.doc/GUID-78E5618F-BD2D-4169-91A4-8FDDCD4C823B.html

under: At Work, application, windows
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3TB Drive

Posted by: martinl | January 23, 2013 | No Comment |

My colleague wanted to by a high capacity external drive for a user and asked me if there were any compatibility issues. I looked up Google and found that there were several limitations,

  1. On Windows, booting from 3TB drive requires UEFI bios as well as 64-bit Vista or higher. Disk has to be formatted in GPT.
  2. As auxiliary drive, still need to format in GPT to make a 3TB volume, MBR supports up to 2.2TB per volume only.
  3. You can have a 3TB volume in a USB box as the SATA-to-USB bridge chip inside the enclosure takes care of any addressing issues. Though, not all enclosures support 3TB disk.

http://www.pcworld.com/article/235088/everything_you_need_to_know_about_3TB_hard_drives.html

under: tech, windows
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10 ways to keep your IT staff from jumping ship

Posted by: martinl | January 15, 2013 | No Comment |

http://www.techrepublic.com/blog/10things/10-ways-to-keep-your-it-staff-from-jumping-ship/3415?tag=nl.e101&s_cid=e101

under: At Work
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Fragmented Windows 8 Backup

Posted by: martinl | December 21, 2012 | No Comment |

http://arstechnica.com/information-technology/2012/12/using-windows-8s-hidden-backup-to-clone-and-recover-your-whole-pc/

under: windows
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