how to mount an app volume to an appliance

[jonesy]

I can't believe this. Every time I inhale it seems something else is here to bite me.

I provisioned the LampCluster application. I need to get ONE stupid file from my old app to the new one. It's a huge file, so I don't want to scp down and back up to the new app. So instead I did a 'vol move' to the new app from the old one. Then I edited my 'dbase' class and told it to mount the volume on /dev/hda3. Guess what? There *is* no /dev/hda3.

I figured maybe this was some trick I missed, but then noticed that /dev/hda2 is in use for a non-boot, app-level volume ('data'), but I couldn't find any difference between that volume and the one I was trying to get mounted.

Where is there a documented process for getting an appliance (in this case, the 'dbase' appliance in LampCluster_1_1_1_1) to mount an app-level volume? I can't find any boot errors or any log messages pertaining to any boot-time errors.

Please help. This is getting old :(

[jonesy]

A couple of other investigative steps:

1. I have tried mounting the volume in question to other, different appliances. *No* appliance can mount the volume.

2. I have tried remapping existing User Volumes on different appliances to the volume in question, and the volume still doesn't get mounted.

3. I got suspicious that something about the fact that this volume was copied from another app, so I created a brand new volume natively in the app, and repeated all of the above. Nothing worked.

I have now restarted my app at least 50 times, and the other thing I wanted to know with respect to that is this: *Should* it *really* take 30 minutes to do an "app restart" on a LampCluster application?

Thanks.

[JosephD]

this issue was resolved online with the client.

Placeholder volumes will not show in /dev/hda* unless you actually give it an application volume to mount.
We are now able to mount his volume in the other application just fine.

Brian if you have another issue with this again please let me know.

Joseph
3tera

[jonesy]

It's true that this issue was resolved, but that explanation of the solution is not accurate, and isn't really helpful to others who might find themselves in the same place I was at - so for those folks...

If you want to create and mount a placeholder volume, you have to create the volume using the "Manage Volumes" option in the application context menu, then create the volume using the "Edit Class" option in the appliance context menu, and then map a block device (/dev/hda*) in the "User Volumes" tab of the appliance editor. But that's not all!

It was initially my understanding that AppLogic would create a mount point for you and edit /etc/fstab. This seemed reasonable to me - so if I created a volume called 'content', applogic would automatically create a mount point called /mnt/content, and create an appropriate entry in /etc/fstab. AppLogic does *not* do this. Once you've done all I've mentioned above, you still have to log into the appliance, create the mount point *yourself*, and edit /etc/fstab *yourself*. Once you do that, you should be able to quickly test if things are working by running 'mount -a'. It should return without error, and running 'mount' should show the new mount in the list of mounted filesystems. If this doesn't happen, you might've done these operations out of order - just restart the application and you should be all set.

hth.
brian.

[PeterNic]

OK, this is correct, if a bit out of order. Let me try to re-state:

1. To have a user-level (data) volume in an appliance, you need to configure your appliance class to have a placeholder volume. This is akin to putting a removable drive bay in a physical server (or putting a CD-ROM drive).

2. In the appliance, if you want to mount the file system of the volume, you need to put it in fstab or run the mount command during appliance startup. Again, this is similar to what you need to do to have access to a disk device on a physical server.

3. Finally, you need to create the actual volume in the application and attach it to the appliance's placeholder. This is akin to buying a physical hard disk and putting it into the drive bay.

All these operations can be performed without a screwdriver :)

Brian, I do appreciate all the feedback and the postings -- this is extremely valuable to us and helps us improve the usability. Even though AppLogic tries to stay out of the appliance as much as possible, I think you have made a good case for having AppLogic create the mount point and add entry to fstab (as a default that can be easily disabled by those who don't want it). We are also considering some assistance on creating the real volumes -- for example, when you drop an instance of a class that has a placeholder, the editor can prompt you to create or attach a volume to it.

Regards,
-- Peter

[PeterNic]

Reviewing this old thread: since the introduction of the appliance kit (APK) in AppLogic 2.3.8 beta, appliances now will/can automatically mount volumes into their filesystems. Check out the APK documentation for your AppLogic version for details.

Thanks, Brian (aka jonesy)!

Regards,
-- Peter

[tsuliman]

It seems like straight forward process can you please post the commands and the actions required I m not sure how to configure the appliance class holder is this the correct link
http://doc.3tera.com/AppLogic29/RefEditorClassEditorSimple.html

[tsuliman]

I had to branch the appliances to modify the boundary volumes tab to do this is there a different way of doing this ?

[tsuliman]

It worked but what I realized is I had to restart the application not the component or the appliance

[PeterNic]

Yes, that must have been it.

Thanks for posting the solution

Best regards,
- Peter