Questions about folders

[Spektakel]

Hello, I have a few questions about folder support on the Cybook with the current (mobipocket) firmware. I know the Cybook does not support folders in the library view, but:

- Can the Cybook read e-books in subfolders of the eBook folder? (I suppose so, since the default demo books are in EN and FR folders...)
- Is it possible to delete existing (EN and FR) subfolders, and create new ones?
- If so, could copying a self-made folder (loaded with e-book files) from a computer to the Cybook cause the Cybook to crash / stop working?
- Could using linux to connect to your Cybook cause problems? (bonus question)

Thanks!

[tompe]

Originally Posted by Spektakel

- Can the Cybook read e-books in subfolders of the eBook folder? (I suppose so, since the default demo books are in EN and FR folders...)
- Is it possible to delete existing (EN and FR) subfolders, and create new ones?
- If so, could copying a self-made folder (loaded with e-book files) from a computer to the Cybook cause the Cybook to crash / stop working?
- Could using linux to connect to your Cybook cause problems? (bonus question)

Yes. Yes. Correctly copying files should not cause any problem. Disconnecting the cable without properly unmounting the disk can cause problem. Run fsck on the file system if you have donw that.

[Spektakel]

Thanks a lot, tompe! Pretty quick, too

I just have sent my Cybook back to Bookeen because of problems that arose after copying files to the Cybook using Linux, and now I'm afraid to do so with my girlfriends Cybook...

[Spektakel]

Originally Posted by tompe

Disconnecting the cable without properly unmounting the disk can cause problem.

So, one more question: what problems have been reported when disconnecting the cable before unmounting / 'safely removing'?

[K-Thom]

Loss of content happenend to some users. That means all ebooks were deleted from the Cybook.

[ErwinOtten]

Originally Posted by Spektakel

So, one more question: what problems have been reported when disconnecting the cable before unmounting / 'safely removing'?

It's just a standard windows thing. When you don't use the ' safely remove hardware' button the computer can still hold access to the disc and corrupt it by pulling out the cable. Don't know if it's the same under linux though.

[tompe]

Originally Posted by ErwinOtten

It's just a standard windows thing. When you don't use the ' safely remove hardware' button the computer can still hold access to the disc and corrupt it by pulling out the cable. Don't know if it's the same under linux though.

In Linux I think buffers are flushed after a certain time interval. It is maybe 10 seconds or so. But it is easy to write and disconnect before buffers are flushed so you should always unmount the device before removing the cable. I suppose you can get a corrupt file system if you are unlucky and one symptom might be that you cannot write to the file system. But that is easily fixed by using fsck.

[Godzil]

Windows by default doesn't use buffering on removable device like the Cybook (it's an option that you can change) so the modification are directly done without using a cache

For XP for exemple:
- right click on the Cybook HD icon and select properties
- In the "hardware" tab clic on the "Bookeen Cybook Gen3 -HD" in the list and clic que "propertie" button
- Choose the "Strategy" tab you have now two radio button with "Optimise for a fast remove" or "Optimise for performances" and the first should be selected by default.

The first one strategy is "don't use a cache to write, do them synchronously"
The second one is "use a write/read cache and flush them asynchronously"


(I translate the windows text from my french XP version to english, so they may differ a little from the original english text)

Originally Posted by tompe

In Linux I think buffers are flushed after a certain time interval. It is maybe 10 seconds or so. But it is easy to write and disconnect before buffers are flushed so you should always unmount the device before removing the cable. I suppose you can get a corrupt file system if you are unlucky and one symptom might be that you cannot write to the file system. But that is easily fixed by using fsck.

For Linux, if you want to be sure that the kernel/fs flush everything, just call sync(1) before anything else. The sync application force the VFS to flush all of it's caches

[tompe]

Originally Posted by Godzil

For Linux, if you want to be sure that the kernel/fs flush everything, just call sync(1) before anything else. The sync application force the VFS to flush all of it's caches

Actually you have to wait some time after sync. From the man page:

On Linux, sync is only guaranteed to schedule the dirty blocks for writing; it can actually take a short time before all the blocks are finally written. The reboot(8) and halt(8) commands take this into account by sleeping for a few seconds after calling sync(2).

So umount seems to be safer...

[Godzil]

Yes, you have to wait, but sync(1) (not sync(2) because it is not the command line tool, but a C function and they not necessarily work the same way, even if sync(1) may use sync(2)) will not exit until the cache has been flushed.

But yes, using unmount is the best way to do.

(And I'm really sorry for all non Linux speaking person here such a message could be really cryptic )

(and the Linux man page for sync(2) have this information:

BUGS
According to the standard specification (e.g., POSIX.1-2001), sync() schedules the writes, but may return before the actual writing is
done. However, since version 1.3.20 Linux does actually wait. (This still does not guarantee data integrity: modern disks have large
caches.)

And flash device does not have such cache.