Open Media Vault to Unraid questions.

[RXWatcher]

I have a OMV server and am considering unraid. My disks arent in a raid array(I've been using snapraid on OMV) and are ext4 formatted.

 

Is there a way for me to keep the data on the disks and move to unraid? It freaks me out to have to figure out how to move around many TBs of data in order to rebuild the server as an unraid server.

 

My setup is currently an ESXI 6.0 server with OMV VM setup with passthrough NICs and HBA. Everything is working ok. I assume I cant run this same config(ESXI host) with unraid? Yes, I realize its not ideal but I have my reasons for running this config.

 

Thanks!

-Jim

 

 

[Ajit]

In order to build your raid, aren't you going to have to backup all that data, so you can format the drives?

[RXWatcher]

I guess that is part of my question: My reading says the drives get wiped when you incorporate them into UnRaid. Why?

They are in a format that can be converted to XFS or BTRFS. I can even convert them before I place them in the Unraid if Unraid cant handle the conversion so why wipe them?

Is this like Oracle's ASM where you put a header on the disk?

 

Ideally, I should be able to move the disks between the two platforms without an issue. I moved them with data into Open Media Vault and SnapRaid without issue.

[itimpi]

I guess that is part of my question: My reading says the drives get wiped when you incorporate them into UnRaid. Why?

They are in a format that can be converted to XFS or BTRFS. I can even convert them before I place them in the Unraid if Unraid cant handle the conversion so why wipe them?

Is this like Oracle's ASM where you put a header on the disk?

In one sense as unRAID writes a signature to the drive so that it can recognise drives that have been partitioned and formatted according to the standards that unRAID expects.

Ideally, I should be able to move the disks between the two platforms without an issue. I moved them with data into Open Media Vault and SnapRaid without issue.

It might be nice, but this is not the way that it works.    You can plug the drives into the unRAID server outside the array (assuming they have a file system that unRAID recognises) for copying files onto the array.

 

I have not tried it, but if you take a disk that has been used by unRAID is this accepted unchanged by Open Media Vault or SnapRaid?

[BRiT]

When you first setup unraid without a parity drive the data drives are imported as is without any data impacting changes provided they are in a filesystem format that unraid understands and recognizes. Currently that is XFS, BTRFS, or RFS.

 

Once you assign a parity drive, then new data drives must be precleared or formatted by unraid.

[RXWatcher]

I really appreciate the insights into this. Thank you for helping me understand without being condescending. It makes me feel welcome here.

 

I wonder why the format is required?

 

I want to build a system that is platform independent. I can currently take my disks and attach them to any linux variant and have them read. This is part of my safety net. If my server blows(I had a lightning strike this summer that took out the motherboard via its nics), then I want to be able to read the drives on a linux desktop machine, etc.

 

The fact that the drives have to be formatted by unraid makes me think they might be in some proprietary variant of XFS/BTRFS that makes it so I cant pull them and place them in a linux desktop after being part of unraid? I can see the parity disk being this way as the parity format is probably unraid specific..makes sense but the data disks? Thats scary.

 

 

[gubbgnutten]

No problems pulling the data disks from unRAID and putting them into another Linux machine if your server blows, standard file systems on the data disks.

[RXWatcher]

If they are standard file systems then why format them when incorporating them into the parity protected array?

 

Per the unraid website: http://lime-technology.com/what-is-unraid/

 

unRAID’s NAS capabilities give you the following benefits:

 

Protect an array of up to 24 devices and utilize 100% of their capacity.

Mix and match devices of different sizes, speeds, brands and protocols in a single array.

Utilize different file systems across individual devices in the array.

Expand your array on-demand without having to re balance data.

Prevent simultaneous multi-device failure from causing data loss on other devices.

Only spin up drives actually in use, reducing power and heat and improving device longevity.

 

 

[itimpi]

If they are standard file systems then why format them when incorporating them into the parity protected array?

This is because if you want to avoid having to recalculate parity then the disk must be all zeroes.   

 

unRAID normally does zeroing option when you add the disk and the array is not available while this is happening (which can take hours with large disks).  This is why you will see mention of the pre-clear script that does this before adding the disk to the array so the array is only offline for seconds.  The preclear writes a signature to the drive that unRAID recognises as meaning the disk has been correctly zeroed and the correct partition structure created.

 

If the drive has an unRAID signature on it then you can do a 'New Config' to clear the current and then add the drives (old and new) without doing a format and then recalculate parity afterwards.  At the moment the 'New Format' option clears all current assignments although it has been requested that an option just to leave the assignments intact but invalidate parity should be allowed to make this faster and less error prone.

[itimpi]

I really appreciate the insights into this. Thank you for helping me understand without being condescending. It makes me feel welcome here.

 

I wonder why the format is required?

 

I want to build a system that is platform independent. I can currently take my disks and attach them to any linux variant and have them read. This is part of my safety net. If my server blows(I had a lightning strike this summer that took out the motherboard via its nics), then I want to be able to read the drives on a linux desktop machine, etc.

 

The fact that the drives have to be formatted by unraid makes me think they might be in some proprietary variant of XFS/BTRFS that makes it so I cant pull them and place them in a linux desktop after being part of unraid? I can see the parity disk being this way as the parity format is probably unraid specific..makes sense but the data disks? Thats scary.

It is not the formatting that is the issue, but the fact that they must be partitioned in exactly the way that unRAID expects.    If you started by doing the partitioning on unRAID (and the initial format) then the disk should be portable to other systems as long as they leave the partitioning intact and the signature that unRAID has written to say the partitioning is as expected.

 

I guess in theory unRAID could look at a disk it has never seen before and if it thinks the partitioning and disk format both conform to what it expects just use the disk, but this is not currently the case.

 

If you are having problems with an unRAID system for any reason it is quite normal to take the disks to another system to work on them there.    If it is a Linux system (which probably understands all the formats unRAID uses) then the disks 'just work'.  If you take them to a Windows or Mac system then appropriate drivers often have to be added.

[gundamguy]

When you first setup unraid without a parity drive the data drives are imported as is without any data impacting changes provided they are in a filesystem format that unraid understands and recognizes. Currently that is XFS, BTRFS, or RFS.

 

Once you assign a parity drive, then new data drives must be precleared or formatted by unraid.

 

I didn't have this problem becuase I built my Unraid system from fresh disks, but just to be clear the approach of making a new unraid system out of existing disks would be to 1) Setup unraid without asigning a parity drive 2 ) Convert the data disks into a recognized format (XFS, BTRFS, or RFS) 3) Add those disks to the array (without a parity drive) 4) Add a parity drive and assign it as the parity drive.

 

If you follow those steps you wouldn't have to format the drives after assigning the parity?

[JonathanM]

They are in a format that can be converted to XFS or BTRFS. I can even convert them before I place them in the Unraid

File system conversion is a risky procedure. I wouldn't recommend trying it unless you have a full backup in case something blows up.

It freaks me out to have to figure out how to move around many TBs of data in order to rebuild the server as an unraid server.

That statement makes me think you don't have backups. If you care about your data, and it would freak you out to lose it, it  needs to be backed up elsewhere. Drive redundancy in the same server is not a backup.

[RXWatcher]

I would say 80% is backed up to Crashplan. The issue is pulling all of that back down. The other 20% are VMs that I could lose if needed so I'm covered.

My main thing is the time it would take to rebuild it from crashplan.

 

I have spare drives and I've pulled the current data disks on my server and have the other drives in there and am experimenting with unraid. If need be, I can mount those data disks outside of the array and move the data to the unraid volume.

 

I just don't know if unraid will work me me. I love the community, I love the docker section. I have no played with windows VMs yet.

 

network setup is a little weird..how do you setup multiple nics?