Hello All,

 

Is it possible to move an array drive to a cache drive without data loss?  I was testing unraid with one drive but i think i am ready to take it to the next level and add a few 2 TB drives.  My main drive is a 512 GB M.2 SSD, if i move that drive from array to cache will i lose data?

 

 

Thank you,

 

Kevin.

Do you want to keep the data on that drive, or do you just want to keep the data from that drive? Do you have a parity drive?

Currently i only have one drive in my array, the 512GB M.2 Sata.  I do not have any other drives in there.  I want to keep the data/config/shares that are on that drive because i set up all my VMs and such.  I have 4 2TB drives that i want to add to the array then make this drive the cache drive.  The data that is on the drive is basically just my 2 VMs that i have and the data/config on them.  Is it just a simple copy the entire drive over to a new place, make a new array and paste back?  I do not want to mess up what i already have.  My Main VM i would like to keep cache only ( speed reasons ) and the rest of my data can be on my hard drive(s). 

If you start by doing Tools->New Config, then when you assign drives unRAID should recognise any that have been previously used by unRAID and add them leaving their data intact.

 

Having said that I think it is always a good idea to play safe, so the following process will protect you against making errors that could result in data loss.

• Start by doing a Tools->New Config to get your system back to a 'virgin' state'
  
• Assign the new drives as data drives and start the array.  At this point no cache drive is assigned.  Select the option to format the drives so that they are ready to receive data.
  
• Mount the old cache drive using the Unassigned Devices plugin and copy its contents to one of the data drives you have just set up.  In theory you should be able to skip this step but this gives you a safety net.
  
• Stop the array and assign the cache drive.  When you start the array its contents should be intact, but if not you have the backup you have just made to the data drives.
  

The above assumes that you want to leave the cache drive using the same file system type as it does at present.  If you only intend to have a single drive then XFS is probably the preferred format.    If you are thinking of using a cache pool then you would have to switch to using BTRFS as that is the only format that supports a cache pool.  Since switching file system types involves wiping the existing contents then it could be done as part of the above process as you would have just made a copy of the old contents which could be restored to a cache drive in a different format