芳草苑

Author: 芳草苑主

  • How to open an mdb exclusively opened by others

    Do not be over excited – my solution is not about how to open an mdb which is truly exclusively opened by others, but to cope with the situation when you can not open the mdb over the network.

    For example, from time to time, Actinic crashes. And sometimes after crash, you see this message:

    There was a problem with the database

    Operation: Opening the table

    The Microsoft Jet database engine cannot open the file ‘\\(netbios name)\Actinic v8\Sites\Site1\ActinicCatalog.mdb’. It is already opened exclusively by another user, or you need permission to view its data.

    Action: Contact your Actinic reseller or Actinic Support as appropriate

    The problem is caused by mdb, not Actinic specific. You may have seen something similar.

    microsoft jet database cannot open file
    microsoft jet database cannot open file

    If you are sure no one else has opened the mdb file, you know Access is talking nonsense. To solve the problem, copy this file, delete the source file (you may have to operate on the local computer), move the copied file to the original place, and that’s it.

    Do not ask me why this kind of problem happens, or why an duplicated file can solve the problem. I don’t know. That is one of the reason I do not like microsoft – too many times I do not know where problems come, and where they go.

  • Email images not showing up in IE8

    I was asked by someone why on his PC images in html emails were not displayed.

    He was using google mail web interface (SSL enabled – Automatically enforce Secure Socket Layer (SSL) connections when your users access Gmail, Calendar, Docs, and Sites) and IE8. I was using the same google mail but Firefox. On my PC the images in html emails could show up. So I thought the problem was with some settings in IE8.

    Following this thought I found it was a setting in IE8: Internet Options -> Security -> Custom Level -> Miscellaneous -> Display mixed content. If it was disabled, IE8 would not http content in a page accessed via https. There should be a prompt before IE8 permanently disable it, but I guess few people can understand this security warning.

    IE8 mixed content security warning
    IE8 mixed content security warning

    This security setting is not only affecting email pages, but email pages are most likely being affected, specially marketing emails. Will we see more eshot programmes embedding img src with https?

  • Fed up with Actinic

    Actinic gave me some trouble this morning. I was reported that Actinic crashed when uploading. My close investigation found that Actinic crashed at the point of checking catalog. No error message was shown on screen. A Catalog_version_number_date_time.dmp was generated but that meant nothing to me.

    Fortunately, there were not many catalogue changes since last successful upload. The cause of problem was quickly isolated to a change of product sequence in a section. As a quick solution, I created a new section, and all products underneath by copying and pasting contents. It was not a desirable way, but what else could I do other than keeping away from Actinic?

    A late investigation when I had some more relax time found that shipping supplement, handling supplement and shipping quantity of the original products causing the crash were changed to some ridiculous figures. I am used to this kind of ridiculous behaviour of Actinic, so I am not keen on finding out the further reasons.

  • I switched Godaddy dedicated server to VPS

    原来在 Godaddy 的独立服务器到期没有续费，昨天我重新订了一台 VPS。其实，这台 VPS 也是并没有大用，只不过预算只能花给 Godaddy，权当是测试 Godaddy VPS 的性能吧。

    使用 Godaddy 的服务两年多，总体感觉满意，尤其满意 Godaddy support 响应比较及时。然而，如今我的资源不一样了，看问题的角度也不一样了，如果重新选择 server 或 VPS service provider 的话，Godaddy 这类名气大的不会是我的首选。一些规模相对较小，或者只是 reseller 级别的 ISP 成了我的首选。只是 reseller 良莠不齐，需要仔细甄别（以前不会甄别，所以只好找 Godaddy 求个省心）。

    Godaddy VPS 可以定制，但挑选余地不大，而且没有 64 位 OS（如果我可以把钱花在别的地方的话，这可以是淘汰 Godaddy 的一个因素）。

    VPS 到手以后，我先装了 vnc server（纯属研究，恐怕没人会拿 VPS 当 remote desktop用吧）。从 VPS 到 vnc server，除了正常的 vnc server 安装步骤，还需要 yum groupinstall "X Window System"，否则登录后是灰屏。GNOME 可以不装，使用 Twm，较 light weight。如果不喜欢，那就 yum groupinstall “GNOME Desktop Environment”。

  • php always takes apache as its session owner

    今天用 yum update php 到 5.2.10 版，发现升级了以后 /var/lib/php/session 的 ownship 又成了 root:apache。这有点恼人，难道每次升级我都要手工改一次 chown nginx:nginx /var/lib/php/session? 或是以后用 apache 的身份来跑 nginx? 我觉得都不太好，太多的场合只认 apache as an only http server，搞得 nginx 很孤立 :(

  • usb disk cannot be accessed by host and guest OS at the same time

    我才知道 host OS 和 guest OS 不能同时挂载一个 usb disk，但是大错已经酿成。

    当时我正在 host OS 里从 host OS 的硬盘移动一些文件到 usb disk 上，然后又在虚拟机里加载 usb disk 给 guest OS，结果，usb disk 就自动从 host OS 里卸载了。卸载时一些文件正在移动，突如其来的卸载造成这些文件未成功写入 usb disk，但源文件却已经从 host OS 的硬盘上删除了。

    Host OS 是 Fedora，这教训给我一个感觉，Fedora (或者说是 GNOME，我不清楚该责怪谁) 的文件操作机制不够可靠——移动文件时，应该在收到目的文件写入成功信号后才删除源文件。

  • Set server’s timezone

    The following command sets the timezone to British Summer Time (BST, UTC + 1) or Greenwich Mean Time (GMT, UTC)
    cd /etc
    ln -sf /usr/share/zoneinfo/Europe/London localtime

    Or, update server timezone
    tzselect

    update server system clock
    ntpdate ntp.org

  • IE8 crash fix

    I recently installed Windows XP in VirtualBox, and did all necessary updates, including IE 8. However, IE 8 kept crashing. At first, I thought it was a problem with VirtualBox or its Guest Additions. The same problem exists in kvm. Then I thought it was a general problem of running IE 8 in virtual machines.

    But inspired by a comment of IE 8, I downloaded IE8-WindowsXP-x86-ENU.exe and re-installed IE 8. The problem has gone. I never expected I have to install IE 8 twice to get it working properly in a newly installed (clean) Windows XP.

  • Send Ctrl+Alt+Fn to VirtualBox guest OS

    Fedora 常用到几个热键：
    Ctrl+Alt+F1
    Ctrl+Alt+F2
    Ctrl+Alt+F3
    Ctrl+Alt+F4
    Ctrl+Alt+F5
    Ctrl+Alt+F6

    VirtualBox guest OS 有时会出现花屏，得用 Ctrl+Alt+F2 和 Ctrl+Alt+F1 刷新一下显示就好了，所有我觉得这几个热键是很重要的。但 VirtualBox 没有提到怎么发送它们到 Guest OS (菜单是只有 Ctrl+Alt+Del 和 Ctrl+Alt+Backspace)，但举一反三，Host+Fn 就相当于 Ctrl+Alt+Fn。这个 Host 键真的很重要啊，我觉得 VirtualBox 设置 right Crtl 作 Host 键真是很好用。

  • VirtualBox 3.0.0 is released

    这两天总有我关注的软件发布更新。

    VirtualBox 从2.24 升级到了 3.0.0，我感觉到两大改进：

    一是 USB 设备访问速度快了近一倍；二是 shared folder 在 Windows guest OS 下访问速度有所提高，但还不及 genuine Windows share，而且打开一个 folder 的速度时快时慢（VirtualBox 2.24 下每次打开 folder 都很慢），所以我还只得继续使用自建的 samba server。

    但有一大退步：
    全屏模式下在屏幕底部出现浮动的 Toolbar，我觉得完全没有必要，很烦人，不是已经有 Host + Home 了吗？