How can a jail die, WITH snapshots? Confused.

[diskdiddler]

I have a sickrage jail which was imported from Warden, into ioCage nearly 8 weeks ago. It has worked flawlessly.

I have daily snapshots of this jail.

Today, some weird bad patch came in from github and I updated and destroyed my jail.
I rebooted the jail, no luck.
I rebooted the system, no luck.
I reverted to yesterdays snapshot, ALSO no luck.
and the day before and the day before that.

I've used an incognito window and a new browser, the WebUI for sickrage is dead.
I can 'console in' to the jail and ping the outside world. I can confirm DNS is working
I can ping the jail from my desktop and from the FreeNAS host.

I'm ok with a jail dying, these things happen but the snapshot reversion isn't working (I even finally know, nowadays, to *stop* the jail, before restoring snapshot, then restart it)
Baffled?

Anyone got any ideas? This is _really_ concerning from the standpoint of me thinking I've got my bases covered, when clearly, I actually don't.


EDIT: Cause of jail failure, nothing to do with FreeNAS, but I do need help with understanding jail snapshots better

 

[diskdiddler]

EDIT EDIT:

I did not have "recursive" ticked.
It seems to me that if I snapshot
"ARRAY/iocage/jails/sickrage_1"

it will NOT grab the subfolders? One of which, most importantly is this?
"ARRAY/iocage/jails/sickrage_1/root/"


Does this mean, when snapshotting your jails, ALWAYS tick recursive?

 

[diskdiddler]

Also what does this mean for my really important data?

/mnt/ARRAY/data/ - I'm snapshotting this, without recursive ticked?
Is this only protecting the root folder / files? and deeper than that, get lost?

 

[Jurgen Segaert]

Did you make the snapshots recursive? That determines whether or not the child datasets will be snapshotted also. http://doc.freenas.org/11/storage.html#id65

 

[diskdiddler]

The snapshot was not recursive, so I'm confused, what exactly does recursive define?

Let me rephrase that


/mnt/ARRAY/iocage/jails/sickrage_1/root/
Isn't root just a child FOLDER? or is it a dataset? Is there a difference?

I have a snapshot of

/mnt/ARRAY/data/
NON recursive

There's hundreds of folders in here, folders, within folders, within folders, files, nested 15 folders deep, images, text, audio - all kinds of junk
These are folders, not datasets? Are these being snapshotted, or .. not?

 

[Jurgen Segaert]

The command zfs list will list all datasets.

A dataset is a ZFS filesystem, with its own properties such as compression rate, quota (reserved space), etc... The mountpoint of the dataset determines where in the file hierarchy it will show up, i.e. the folder. When you create a pool, it automatically creates a root dataset with the same name. All other datasets will be nested in that root dataset and can have their own child datasets.

 

[diskdiddler]

The command zfs list will list all datasets.

A dataset is a ZFS filesystem, with its own properties such as compression rate, quota (reserved space), etc... The mountpoint of the dataset determines where in the file hierarchy it will show up, i.e. the folder. When you create a pool, it automatically creates a root dataset with the same name. All other datasets will be nested in that root dataset and can have their own child datasets.

It does indeed seem that these 2 are defined as 2 different datasets.
ARRAY/iocage/jails/sabnzbd_2
ARRAY/iocage/jails/sabnzbd_2/root

I don't understand why exactly it needs to be that way specifically for the jails but so be it.

So I DON'T need a recursive for my /data/ then? (it's the only dataset for that path and sub path)

 

[sretalla]

It makes sense to me that if you don't keep your jail config and data inside your jail root filesystem (like is recommended here), then you have no real reason to have snapshots of the (effectively disposable) jail root filesystem, since you can always just re-create it if it's broken and re-attach your config and data using fstab/mounts.

I can see why somebody might want to take a backup of the jail root filesystem if they were keeping important data in there, so having a separate dataset for it is a good thing.

 

[diskdiddler]

It makes sense to me that if you don't keep your jail config and data inside your jail root filesystem (like is recommended here), then you have no real reason to have snapshots of the (effectively disposable) jail root filesystem, since you can always just re-create it if it's broken and re-attach your config and data using fstab/mounts.

I can see why somebody might want to take a backup of the jail root filesystem if they were keeping important data in there, so having a separate dataset for it is a good thing.

In hindsight, I totally agree.


That being said............
The location of the configuration data is not always consistent unfortunately. If someone here posted a guide of exactly which paths, I need to re-map in order to achieve this? No hesitation.

I've done a few like this, thanks to a guide someone wrote but literally 2 out of my 10 jails