BTRFS support on Gen2? Maybe

So, I started looking inside my snazzy EX2 ultra I got to replace my damaged Gen2 (cats on shelves are adorable, until they knock expensive disks over!), just to see what additional kernel modules it has baked into its cramfs blob. Turns out, it supports btrfs. (shock!)

Why is that exciting? Well, btrfs supports seamless in-place filesystem compression with a variety of compression algorithms, one of which is zstd. In prior tests of this FS, I determined that it gets about double the compression efficacy of NTFS file compression, and does it more sanely too. (No scattered file extents all over the darn place.)

Since the EX2 and the Gen2 single bay units both use the same exact kernel, it should be possible to re-bake the crafms container to add the missing module, and poke the init script at the same time to make it load.

More fun experiments to try tomorrow! :smiley:
Looking at the hd_info.xml file in /usr/local/config, it has an entry for filesystem type. I think I will try re-baking the cramfs container as outlined above, and then testing if I can get the main volume to use btrfs on the newly revived gen2. Since I have adapted it to use flash memory, it’s capacity is going to be very small (only 1TB), but turning compression on should do wonders.

Hi Wierd_w,

You can refer the information provided in the link below as any changes in the device which WD does not recommend can void the warranty of the device.

Other than replacing the disk during the warranty. What does WD do anyways. Also
most of the people with Gen1 and Gen2 devices are already out of warranty.

Oh, I voided my warranty a long time ago Brandon, but thanks. :stuck_out_tongue:

I bout the mycloud about 2 years ago, and the original disk suffered “G-force related” (ahem) failure after my darling kitty cats knocked the unit off the shelf and onto a hardwood floor. WD would be very unlikely to offer me warranty service for that kind of thing, so I never bothered. Instead, I have taken to learning everything I can about the hardware and software configuration of the device, in order to get it to do fun and interesting things.

As rac8006 points out, most of us are far outside warranty support anyway. At this point the danger is in rendering your unit non-operational, which we (community) know how to recover from, due to the tinkering we have been up to over the past few years.

This thread is not intended for normal users. The things discussed herein certain will void your warranty. :slight_smile:

realize this is an old thread, but worth learning more about …

namely, can i enable btrfs support for external USB disks ? if so, i want to experiment with converting one of my USB drives over to btrfs format and connecting it to the EX2 to see if it would be recognized.

interested in migrating over to this fs both with an external usb drive as well as internally on the NAS, but i think making it the native fs would take a lot of work ?

i did not realize this is an OS3 topic, and i am on OS5 just pointing this out.

Sadly, the kernel module baked into the stock kernel is so ancient, and so buggy, that it causes instant kernel panic the very instant you try to mount a BTRFS file system.


interesting to know that. its a slick looking filesystem but i thought about possible compatibility and file access issues if a disk is pulled from service due to NAS or drive failure.

nevertheless, if a drive did fail in a my cloud device, little options to rebuild an array.

lots of decision drivers led me to part ways with wd products, call it ‘irreconcilable differences’ …


biggest shocker to me with respect to wd in general is poor customer service.

poor quality products is a close 2nd.

ultimately i forked the money to get something better.