Film-Tech Forum ARCHIVE: Problem ejecting hard drive on windows 7

This is topic Problem ejecting hard drive on windows 7 in forum Film-Yak at Film-Tech Forum ARCHIVE.

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Posted by Mike Heenan (Member # 392) on 11-23-2011, 08:25 PM:

I am a mac guy and had a problem with my mom's laptop which runs windows 7. I was making a backup onto an external Hd and when I ejected it safely, it ejects but then immediately mounts again. It's a seagate Goflex 2tb desktop drive. Not sure what the issue is here, it ejects fine on my mac. Anyone have this problem?

Posted by Edward Havens (Member # 4715) on 11-23-2011, 08:47 PM:

Nope. I'm a Mac guy too. [Smile]

Posted by Monte L Fullmer (Member # 2797) on 11-23-2011, 08:56 PM:

Close the program that is accessing the HD, then you can pull the USB cord.

Windows sees the ext HD's as "removable drives" when connected via the USB cord.

That's the easy fix for us who uses PC's...

"Mount and Dismount" reminds me of how AMIGA's handled their external devices...Course, if I remember, Jobs had a handle with AMIGA as well.

Posted by Leo Enticknap (Member # 534) on 11-29-2011, 04:53 AM:

quote: Monte L. Fullmer
Close the program that is accessing the HD, then you can pull the USB cord.

If write-behind caching is enabled, doing that could result in corrupted files. On an NTFS volume, write-behind caching is an operating system function whereby, when you tell Windows to write something to a disc, it might not actually do it straight away if the processor and/or hard drive controller is busy doing something else. Instead, it'll cache the data to be written to memory, and then dump it out to the drive when it becomes free. The idea is to avoid compromising performance on 'here and now' task.

The problem is that if you pull the USB plug while data is still waiting to be written, the pending files will be corrupted on the external drive, even if you think you've closed all the applications that were using it. If caching is enabled, the only safe way to remove the volume is to click on the removable drive icon on the taskbar notification area (bottom right), and select the volume you want to remove. Windows will then write any pending data immediately and then tell you that it's safe to pull the plug.

A how-to on enabling and disabling write-behind caching in Windows 7 can be found here. If you want to be able to just pull the plug at any time, disabling the caching will enable you to do this safely, but you might take a performance hit (especially if you're using a slow flash drive).

Incidentally, the above just applies to NTFS volumes, not FAT. Write-behind caching is not possible with FAT drives, and you can just pull them at any time that the computer isn't explicitly telling you that it's in the process of writing something.

Posted by Mike Heenan (Member # 392) on 11-29-2011, 04:54 PM:

Thanks for the link, I'll read about that later. The drive is formatted for NTFS, so I can easily swap between my mac and pc. The drive is my storage drive for movies and whatnot, since FAT32 has a file size limit on it, it's got to be NTFS. What I've been doing after copying data to it is ejecting the disc, and as soon as it says it's safe to do so, I pull the power adapter on it before it has a chance to remount.

Posted by Chris Slycord (Member # 4239) on 12-01-2011, 12:27 AM:

I know this isn't the best solution out there in that it's a nice kludge, but the way to pretty much guarantee that the disk is not mounted is to put the machine into shutdown mode. It'll do any of its remaining disk writes before powering itself down. It's an exercise to the user to figure out what to do at that point [Wink]