File or database corruption when using USB

[Renate]

I read on another thread people arguing whether Kindle or Kobo is more prone to file or database corruption when using USB to synchronize. That amazes me that people would put up with any such occurrences. So my questions are:

• Does any model ereader still use UMS? That's where the reader is locked out when attached to USB.
• When corruption occurs do you lose contact with content on your device or only last reading position / reading history?
• Can't you just press a button, "Find my content"?

[Sirtel]

Originally Posted by Renate

• Does any model ereader still use UMS? That's where the reader is locked out when attached to USB.

They all do, in my experience.

[pdurrant]

Originally Posted by Renate

I read on another thread people arguing whether Kindle or Kobo is more prone to file or database corruption when using USB to synchronize. That amazes me that people would put up with any such occurrences. So my questions are:

• Does any model ereader still use UMS? That's where the reader is locked out when attached to USB.
• When corruption occurs do you lose contact with content on your device or only last reading position / reading history?
• Can't you just press a button, "Find my content"?

By its very nature, file system corruption can cause anything from a dead device to a missing file/folder to nothing visible.

Corruption will only happen if the device is disconnected before changes to the file system have been completely written to the device.

[JSWolf]

I don't find a Kobo or Kindle to be more prone to corruption then the other.

[theducks]

Originally Posted by pdurrant

By its very nature, file system corruption can cause anything from a dead device to a missing file/folder to nothing visible.

Corruption will only happen if the device is disconnected before changes to the file system have been completely written to the device.

This is why there is a You can Safely Eject message . The data to be written may be buffered on your PC, so control can be returned sooner. The buffer continues at whatever speed (and error correction) as needed.

It is still BEST to wait for the device to also show it is done processing (My Kobo takes about 20 seconds AFTER the SAFE message to Start 'Processing' NEW books) and stabilizes on the standard user screen.
FWIW not only are books being transfered, but I think Calibre also does an update of the metadata.calibre speedup file if that is what you use. Mine is 500K for 50 books on my Aura2

[Calenorn]

Originally Posted by theducks

It is still BEST to wait for the device to also show it is done processing (My Kobo takes about 20 seconds AFTER the SAFE message to Start 'Processing' NEW books) and stabilizes on the standard user screen.

This. My old PC will display a "safe to eject" message, but that has no bearing on what the ereader is doing. Patience is worthwhile.

[Renate]

I am really amazed. I would have thought that only someone with a 10 year old Russian ereader would have UMS.

Even the Glow series from B&N do not use UMS, but MTP.

I use only ADB. Unlike MTP there's no flurry of communication when you connect. You can pull the cable at any time without a problem. If that was in the middle of a book, the transaction won't be completed, but the next sync will transfer it.

Seriously, UMS is ancient, but more especially, bad technology.

[Quoth]

Originally Posted by Sirtel

They all do, in my experience.

Only MTP and Network USB gadgets don't lock the screen. The iRiver Cover Story, Binatone Android 3, Sony PRS, older Nook eink, all Kindle eink except Scribe (it's MTP), all eInk Kobo all lock the screen.

The database corruption issue on some Kobo FW versions is complex. I've not had such happen for a long time, even though I manage five Kobos (4 models) regularly and the two Sage models very often. I have used maybe 7 models of Kobo and only saw it a few times. The current issue can be due to the database not being closed before USB connects, that's a FW issue. Obviously disconnecting the cable while something is ongoing can also cause an issue.

The symptoms of corruption vary.

Amazon sync messes up collections if you have a PW3 and DXG on the same account. I've seen database corruption a few times on Kindles, nothing to do with USB.

Originally MS introduced MTP as an extension to PTP for DRM on the Zune.

Google switched Android from Mass Storage USB to MTP with Android 4.x and the reason may have been security.

Above 32G there is another reason. The Kindle Scribe is the only Kindle currently with a more than 32G option (the 64G model). More than 32G on an SD Card partition really needs exFAT rather than FAT32. Mass Storage mode is usually FAT32 because it's the only format everything supports that has longer paths and filenames. MTP and Network USB (reMarkable and some gadgets) allow any arbitrary file system on the 'gadget' as the MTP or TCP/IP are protocols for data transfer/communication, not file access. Windows has a driver layer that uses MTP and emulates a filesystem for the OS, so more than one process can connect (because they developed MTP), though I think originally only Windows Media Player connected to transfer (a bit like iTunes for an iPod). Mac and Linux are limited to one process, so if it's 'mounted' for Finder or a File manager, then no other application can connect direct. On Linux Mint with Mate Desktop (not with Cinnamon) I might have to stop (not kill) the gvfs-mtp-volume-monitor. With some MTP devices unmounting will allow calibre to connect, others can't, so gvfs-mtp-volume-monitor has to be stopped before connecting the cable.

[Sirtel]

Originally Posted by Renate

I am really amazed. I would have thought that only someone with a 10 year old Russian ereader would have UMS.

Even the Glow series from B&N do not use UMS, but MTP.

I use only ADB. Unlike MTP there's no flurry of communication when you connect. You can pull the cable at any time without a problem. If that was in the middle of a book, the transaction won't be completed, but the next sync will transfer it.

Seriously, UMS is ancient, but more especially, bad technology.

First, most ordinary users (including me) have no idea how to connect in any other way than what the device does out of the box (I don't even know what ADB is); second, for calibre users there IS no other way. I want Calibre to automatically update the metadata and collections on my Kobos when I connect; for that, I need to connect to Calibre, not only to my PC, which can only be done via UMS.

[Quoth]

Originally Posted by Renate

Seriously, UMS is ancient, but more especially, bad technology.

No, it's different technology. All SD cards and USB memory sticks and SATA, IDE or native USB HDD /SSD use USB MS.
ADB is much faster than regular MTP with an MTP device. I've used it on console. Disadvantage is the host OS has to support the Filesystem. It's much better when NTFS or Ext4 is used rather than FAT32 or exFAT. Linux copes with NTFS (older or newer) fine. Mac needs 3rd party tools for NTFS or Ext4. I do have one Windows XP with Ext2 support, but mostly MS Windows didn't support any Ext version. This is why most gadgets use FAT32 or exFAT if not using MTP or networking. Usually the OS is on a separate Ext format partition.

Amazon Kindle doesn't have the important database on a user accessible connection, that's why it's a walled garden and you rely on Amazon for Series, Collections etc. The Kobo has the database accessible. The title and author is set by the Kobo when it imports, but subsequently a 3rd party like calibre can set also subtitle, collection(s) and series after the book is imported. Thus 2 connects are required. A Kindle needs jailbroken.

However MTP is abysmal for directory/folder listing or browsing and only works flexibility on MS Windows. It also will time-out. It's not better, just different.

[Quoth]

Calibre does support MTP, but it depends on the device as to how much more than a file transfer can happen. Only the Author and Title is universal in Mobi/azw/azw3/kfx/epub2/epub3 via metadata in a file for all gadgets and Android apps.

[jhowell]

Originally Posted by Quoth

Only MTP and Network USB gadgets don't lock the screen. The iRiver Cover Story, Binatone Android 3, Sony PRS, older Nook eink, all Kindle eink except Scribe (it's MTP), all eInk Kobo all lock the screen.

Although the Kindle Scribe uses MTP it still locks the screen user interface while a device is connected over USB.

[Renate]

Originally Posted by Quoth

No, it's different technology. All SD cards and USB memory sticks and SATA, IDE or native USB HDD /SSD use USB MS.

No, it's just bad.

Nowadays all flash drives have pretty smart controllers built in for wear leveling. If you can keep track of how many times each page has been used you should be able to keep track of files. That there is not a common USB protocol for this is another matter.

When the AI machines take over they will ridicule us endlessly for perpetuating UMS.

[DiapDealer]

Originally Posted by Renate

When the AI machines take over they will ridicule us endlessly for perpetuating UMS.

They're going to be waaaaaaay too busy trying to kill Sarah Conner in the past to worry about ridiculing us over UMS.

[Quoth]

Originally Posted by Renate

Nowadays all flash drives have pretty smart controllers built in for wear leveling. If you can keep track of how many times each page has been used you should be able to keep track of files. That there is not a common USB protocol for this is another matter..

USB is irrelevant to that as is the File system format. That is hidden in the internal controller. An OS shouldn't know about it.