El Capitan not seeing external disks...

Thanks! I totally missed the implication of that sentence, Max108.

If you're reading this later, the relevant sentence is this:

USB storage devices, including internal SD card readers, may become unavailable after system sleep and require either re-plug or restart to recover.

Oh well. I did the direct plugin and restart, and it seems to be working, now.

Thanks again,

/Ian

Wow. Glad I caught this.

That's certainly the last time I upgrade to any version of a dev preview without reading every line of the release notes first. El C has already broken tons of stuff I use on a day to day basis, and this is one risk I won't take. And frankly I am shocked that Apple would put out a new release without fixing such a huge known issue first.

Edit: I wonder if this was also noted in dev prev 1? Any idea how to view the previous version of the linked document above?

ignorant: did you upgrade to beta 2 after using beta 1 successfully with your drives attached to a hub?

in my case, direct plugging drives is not possible. I use 3-4 on a regular basis, and don't have the available ports without a powered hub.

Well I have the same problem, if anyone gets how to fix it, please do not hesitate to let me know. Thank you.

Sorry to hear that. But I'd like to know: did you jump straight to dev preview 2, then experience this problem? Or did the drives work normally on dev preview 1?

There seem to be a few issues with Disks for EC so far. Startup manager is mostly non functional for me. I have 3 bootable partitions and all three show. However only the EC one works, the other two end up in EC as well.

Even when booting using the Command key the same thing is true. They list differently there, but still same result.

What is really odd is what makes them begin to work. Make a bootable install thumb drive with some version of OS X on it (doesnt seem to matter). Power down the mac and insert the thumb into the hub. Power up and use Command key, then all partitions show, including a recovery for each bootable partition, and they work correctly. Then the other bootable partitions work. More so, you can use the regular startup manager within OS X to boot between the other two. But one you return to EC, the incorrect cycle repeats.

It all begun on dev preview 1

no external usb hdds

no usb sticks

but my time machine external HDD works just fine

Thanks for that. Fortunately for me, my external USB drives worked ok under dev prev 1. For that reason I dared take the plunge to dev prev 2. So far so good on that score. So I might conclude if you installed dev prev 1 first and had your external drives behave ok, there is at least a good chance they will continue to do so under dev prev 2. If they didn't under #1, then… Unfortunately there are other new issues but I won't get into them here.

Well, after all I now updated to DP3 and all my external devices are working perfectly again!!! wish you guys the same.

I still have this problem with DP4, no external USB drives and sticks, you can see them in Disk Utility but that's it you cannot mount it

Any solution to this problem? It's ridiculous

Mine mount and access OK, but generally fail to boot. If you shut the system down, then reboot and hold the ALT key, the partitions show then and will boot. OW, not.