initramfs fails to find root filesystem on recently updated system

On a recent installation of Ubuntu 18.04, the system has installed fine. However attempting to upgrade the systems kernel from kernel image 4.15.0-29-generic to 4.15.0-43-generic the kernel would panic due to no found root filesystem.

[   0.327121] md: Waiting for all devices to be available before autodetect [   0.327823] md: If you don't use raid, use raid=noautodetect [   0.328622] md: Autotecting RAID arrays. [   0.629322] md: autorun ... [   0.330013] md: ... autorun DONE. [   0.330722] VFS: Cannot open root device "UUID=<UUID>" or unknown-block(0,0): error -6 [   0.331434] Please append a correct "root=" boot option; here are the available partitions: [   0.332162] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) [   0.332878] CPU: 2 PID: 1 Comm: swapper/0 Not tained 4.15.0-43-generic #46-Ubuntu [   0.333599] Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X99 Extreme4, BIOS P2.00 06/01/2015 <KERNEL CALL TRACE> 

As you can see when attempting to load the filesystem from within the current initramfs (4.15.0-43-generic) no disks are detected. Switching back to the previous initramfs (4.15.0-29-generic) still allowed the root filesystem to be detected and loaded.

At a later point (several updates) even the 4.15.0-29-generic initramfs failed to find the root filesystem.

As of right now I have checked all disks to SMART, flashed the motherboard with an updated UEFI firmware, and performed multiple fscks against the filesystem. At this point the GPT layout looks fine, there are no filesystem errors, and SMART has come back with no disk faults or errors.

The only way I have found to continue booting the system is to pull the initramfs modules from the Ubuntu 18.04 Live CD and rebuilt the original initramfs for 4.15.0-29-generic. This process has at least been met with limited success in that I can once again boot the system albeit without any extra modules such as the nvidia display drivers.

Any suggestions would be appreciated.

how to mount filesystem on to an existing (non-empty) directory?

How can I mount a new fs (fuse) on to an existing directory where my application is writing? Details on the issue: I have /var mounted as ext4. My application writes the data to /var/lib directory (/var/lib is NOT mounted). How may I do this without restarting my application? On trying to create a mount for /var/lib, I see following message. I am worried about losing existing data in /var/lib to continue with option “nonempty”. “

starting fuse filesystem fuse: mountpoint is not empty fuse: if you are sure this is safe, use the ‘nonempty’ mount option

Thanks, Dinesh

Command Line Utility For Browsing Apple’s Photo Database Like a Filesystem

Is there a command-line utility to allow browsing and editing photos in the Apple Photos database like you would browse a file system? The Photos app is really terrible when trying to perform operations on large data sets (in my case, delete all of the thumbnails that I accidentally imported) as it foolishly tries to load all of the photo metadata into memory when making selections of matching files to perform any select and this brings my computer to a halt as it allocates 101 GB of virtual memory and it just sits there paging for hours. I have tried to use third party “deduplication” tools but they are all terrible. I really just want to perform some basic operations on them using tools like exiv2 and GraphicsMagick to write some shell scripts to do get what I need done so I don’t have to put up with Apple’s nonsense with Photos. Any ideas? I have not found anything yet. Honestly, a Fuse plugin would be ideal, but alas- such a thing does not seem to exist.

What marks data as deleted – the hard drive or the filesystem?

Anyone with a cursory understanding of data recovery and sanitisation as it relates to hard drives is aware of the concept that data “permanently” deleted from within an operating system is not deleted, but simply marked as such in the MFT, and that the data exists on the drive until the sector that it occupies on the hard drive is overwritten with new data.

However, I recently realised that I’m hazy on whether this process is a function of the hard drive itself, or the filesystem on it (NTFS more than likely, since we’re talking about the MFT). If it’s the former, how different is this process in mechanical and solid state drives? If the latter, do other filesystems (apart from NTFS) handle the deletion of data radically differently?

Download image of filesystem on broken Nexus 5X

I have a Nexus 5X phone that died one day out of the blue (well, I had dropped it the day before). Now it boots to the point that “Google” is displayed on the screen then turns itself off. I can get it into fastboot, however.

I’m not so much concerned with reviving the phone as I am with getting a certain 50 MB audio file off the phone. Fastboot lets you upload an image, but I’d like to download a complete image of the phone if at all possible. Or just that audio file.

I had turned on developer mode before the phone died, but I hadn’t unlocked it. This is important enough to me that I’m willing to root around in a binary image of the phone, if I can download it to Linux on my desktop.

Any ideas on how to do this?

Create clean/blank MacOS filesystem for testing OSS

In developing/testing OSS libraries I can replicate a clean Linux fs using containers. However, if I want to test oss libs for MacOS end users, I seem to be in a bit of a quandary. Is there any way to create a clean fs on MacOS that I can test libraries with? Perhaps using chroot? Can someone explain exactly instead of just saying “use chroot”?

Motorola Nexus 6 won’t show its filesystem

I’ve had a Motorola Nexus 6 for some time now, and I tend to be a bit static with it — I’d uploaded the majority of my music library at the time and then didn’t change much for a long time.

Now I recently purchased a number of new songs and wanted to upload them to my phone, but when I plug it into a computer (any computer I’ve tried so far, two linux systems and one windows 10) they recognize the Nexus 6, but when I try to open it in a file manager they only show an empty folder. Rebooting either the computer or the phone had no effect.

When I attempt the same thing on my Samsung Galaxy tablet, the tablet prompts me to enable sharing and after I confirm that I can browse the filesystem on my tablet, but the Nexus 6 phone never shows me that dialog.

It’s entirely possible that I accidentally enabled a security feature and forgot about it; can anyone offer suggestions where I should start looking?