usb delayed write – (some explanation)

FROM: Remove_Sticks_Safely.pdf [APC – Magazine; Page-102 ~ February 2008]

When you write data to a USB storage device, there’s no guarantee the data is written at that exact moment.

This is the result of the operating system storing up read and write jobs so they can be executed in a single batch – speeding up performance and providing a better user experience.

However, if you remove the device before the data has been written you’ll lose the data.

This is why 0S X, Windows and Linux ask you to warn the operating system youre about to remove the device – usually by clicking on an icon or menu option.

GRD-COMMENT ~ That explanation is VERY good – and provides REASON enough WHY any user should ‘Remove_Sticks_Safely’

ANOTHER SENARIO: – (Saved as text files, so pasted here)

FROM – URL: –,2817,1819756,00.asp

Disabling Delayed-Write in Windows – 05.18.05 – by Neil J. Rubenking

Microsoft Windows has a feature that, at least for me, is very annoying. When I transfer files to an external device, such as an external hard drive, Windows indicates when the task is completed. However, if I immediately disconnect the external device, I get a Windows error message saying that the transfer of files was not complete because delayed-write was not finished. In other words, Windows continues its transfer process in the background for several minutes after it gives all appearances of having completed the task. Is there a way to determine when the delayed-write process is actually completed? Or, even better, is there a way to disable delayed-write so that Windows transfers only files in real time and does not report the task as complete until it is actually completed?

David A. Coup

If the drive is connected via USB, you will normally see an icon appear in the system tray when you plug it in. You can right-click on the icon and “Stop” the drive, which forces all pending writes to complete. Windows then reports that you can safely remove the drive. If it’s another type of external device, try disabling write caching for it in Device Manager. Specifically:

# Right-click on My Computer and choose Properties.

# Click on the Hardware tab.

# Click on the Device Manager button.

# Find the device in the list, probably under “Disk Drives.”

# Right-click on the device and choose Properties.

# Click on the Policies tab.

# Uncheck Enable write caching on disk.

# Click on OK.

That should do it. Note that you can disable write caching for internal hard drives as well, but doing so may affect system performance.