I built an unRaid server, and had 6 drives which I pre-cleared, installed plugins etc. Then my server died ! It will take me a while to get a new server ready, in the meantime I have some questions -

 

1. I read that XFS drives have to be formatted in unRaid. i.e. if I make an XFS drive in Ubuntu, unRaid won't accept it. Is this true?
2. Is there a way to make an unRaid compatible drive in another OS? Isn't it just zeroing the drive and adding the special header?
3. Can I mount and write to the XFS drive in Windows and then can unRaid use it just fine? 

 

I have a lot of  data to transfer, so I want to use this time to prepare drives and move data to them, so they are ready to be used in the new server. 

Is this possible?

Edited May 9, 20179 yr by MrCrispy

As far as i know, no. You must do this on unRAID. And Windows cant create an XFS partition - its a Linux format but you could use a Linux Live-CD to create a XFS-drive. There are tools to read XFS on windows, but whether they work proper... dont know.

Maybe you can create an XFS drive under Linux and put it to unraid, if you "dont" use a parity drive. But as soon as you use a partity disk, its over. Then you must create it under unraid.

Maybe the Experts here in this forum can explain it more detailed and nows more about this fact.

 

EDIT: What could work - i never tried it - is to add all your XFS-Drives with data on it and "finally" add the partity drive and let unraid create the new parity, but as i mentioned, an Expert could explain this in more detail.

Edited May 9, 20179 yr by Zonediver

You have to get the partioning exactly right for unRAID to accept the drive as well as formatting it correctly to XFS.  This means it is always easiest to let unRAID do the initial partitioning and formatting.

 

Once that is done the drive can be plugged into another Linux system to add data and the drive can later be moved back to unRAID and (as long you are not adding the drive to a new slot on an existing array that is already parity protected) the data will be recognised by unRAID.   This can be useful when setting up a new system.

Does unRaid use some special partition format, and its not standard XFS?

Can I run unRaid in HyperV, pass thru a USB device, format it and copy data  to it? This seems like the easiest way.

 

4 minutes ago, MrCrispy said:

Does unRaid use some special partition format, and its not standard XFS?

 

It's not special, there can only be one partition, it needs to start on sector 64 and extend to the end of the disk, or else unRAID will repartition it when the disk is added to the array making it unmountable.

1 hour ago, johnnie.black said:

 

It's not special, there can only be one partition, it needs to start on sector 64 and extend to the end of the disk, or else unRAID will repartition it when the disk is added to the array making it unmountable.

 

Still unclear - if I format a drive as XFS in Linux, e.g. Ubuntu, and copy files to it, can unRaid use it? I found this - 

 

Quote

 There is another 'catch' though: at present unRaid computes block-level parity across "partition 1" of each device.  In order to maximize storage a decision was made long ago to create an 'unRaid-standard' partition layout on each device.  Bascially it expects a single partition 1 to exist on the device starting in sector 64 and extending to then end of the device (and for devices 2TB or smaller to be legacy MBR-style partition structure and for devices larger than 2TB to be GPT-style partition structure).  Unfortunately most devices 'formatted' outside of unRaid tweak the partition layout it subtle ways that make it 'compatible' - bottom line: most of these devices appear unformatted even though they might have a valid partition structure and file system.  Anyway this is some we plan to correct in a future release.

 

So this was never done I take it? (w.r.t to last sentence)

It seems to be it should be possible to get this partition layout manually using fdisk, right? It asks for the partition number and starting sector.

 

Can someone confirm this? 

3 minutes ago, MrCrispy said:

Still unclear - if I format a drive as XFS in Linux, e.g. Ubuntu, and copy files to it, can unRaid use it? I found this - 

 

You appear to not understand the difference between partitioning and formatting a disk, as long as the disk is correctly partitioned you can format it wherever you want, but in case of doubt and you're not understanding what you're doing better to use unRAID only.

1 hour ago, johnnie.black said:

 

You appear to not understand the difference between partitioning and formatting a disk, as long as the disk is correctly partitioned you can format it wherever you want, but in case of doubt and you're not understanding what you're doing better to use unRAID only.

 

I do understand the difference and I thought I made it clear by mentioning fdisk, or equivalent diskpart in Windows. But I still don't have an answer to my question.

 

Let me repeat - is there any way to make and fill up XFS disks for later use in unRaid? Either using Linux or unRaid running in HyperV. 

1 minute ago, MrCrispy said:

Let me repeat - is there any way to make and fill up XFS disks for later use in unRaid? Either using Linux or unRaid running in HyperV. 

 

3 hours ago, johnnie.black said:

 

It's not special, there can only be one partition, it needs to start on sector 64 and extend to the end of the disk

 

Asked and answered.

18 hours ago, MrCrispy said:

Is this possible?

 

Seems the actual answer is Maybe

 

... as discussed above, the partition must start on sector 64 and extend to the end of the disk.   As long as this is true, it should work fine in UnRAID.    I do not know which Linux versions/partitioning tools support creating partitions with these specific partitions.   I agree the best thing to do is simply create your partitions on an UnRAID system ... you could then move the disks to another Linux system and write your data there if that's more convenient.

 

Ive been reading all day and it seems there is no reliable way to run unRaid virtualized. I don't have an extra pc for this, otherwise I'd just format in unRaid. Which is why I want to confirm.

Quote

Enter expert mode in fdisk and change the starting LBA of the partition to a value that is evenly divisible by 8. In the following example, the default starting sector is 63 and we will change it to 64 because 64 is evenly divisible by 8. The default starting sector chosen by fdisk is based on the size of the LUN. fdisk uses the LUN size to calculate a pseudo geometry which can vary between different versions of fdisk.

Command (m for help): x

Expert command (m for help): b
Partition number (1-4): 1
New beginning of data (63-62926604, default 63): 64

 

Will this create a partition unRaid can read? 

 

 

9 hours ago, MrCrispy said:

Let me repeat - is there any way to make and fill up XFS disks for later use in unRaid?

 

I already answered you twice, but looks like I wasn't clear, so let me say it one more time:

 

As long as the disk is properly partitioned and formatted in one of 3 filesystem recognized by unRAID it can be done elsewhere, including ubuntu.

 

Assuming the disk is >2TB it needs to be GPT partitioned, easiest way is to use sgdisk, like so:

 

sgdisk -o -a 64 -n 1:64:0 /dev/sdX

This assumes a cleared disk.

Edited May 10, 20179 yr by johnnie.black