My Unraid system is running on a Dell T440 with a Dell BOSS controller containing two 256G SSDs. These are in a RAID-1 redundant array. They appear to Unraid as a single 256G volume that is a Cache Pool device.

 

I have created two Virtual Machines with their vdisks in that volume:

/mnt/user/domains/Windows 11/vdisk1.img (cache)

/mnt/user/domains/Debian/vdisk1.img (cache)

 

I'd like to replace these drives with 1TB SSDs.

 

Is there any guidance or procedure for imaging these disks and expanding the storage?

Can the controller do it itself? I.E. install one new drive, start up and the controller will replicate the remaining 256G drive onto the new 1TB drive? Then replace the other and it will replicate again?  Is there any partition steps required to expand the partition to use the full size?

 

 

17 hours ago, timg11 said:

They appear to Unraid as a single 256G volume that is a Cache Pool device.

This is not recommended, Unraid should get direct access to the devices, and you could then just upgrade the devices one by one.

So apparently the BOSS card was already configured as RAID1 in the T440 server when I installed Unraid.

 Here's how it was detected and now appears in Unraid:

 

How would I give Unraid direct access?

 

Presumably along these lines:

1) Stop VMs running on Cache device

2) create image of existing Cache Device and save onto array. (How is that done in Unraid? just cp, or is there a better tool?)

3) shut down Unraid system entirely, remove 256G SSDs and install 1T SSDs

4) boot into T440 BIOS and use BOSS configuration to make SSDs independent.

5) boot into Unraid and configure Pool Devices (presumably now there will be two) into a single Cache drive controlled by Unraid (Any guidance on that process?)

6) restore saved image on array back to cache device.

7) restart VMs

 

1 hour ago, timg11 said:

How would I give Unraid direct access?

Connect the devices to a SATA/SAS non RAID controller.

 

1 hour ago, timg11 said:

Presumably along these lines:

You can use this to backup and restore a pool:

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/#findComment-511923

 

Thanks for the link for backup and restore a pool. I think I could move the pool to the array, upgrade the SSDs, initialize them, then move the pool back to the SSDs.

 

I'm not sure what Unraid would do better than the BOSS if I disable the intelligence on the BOSS S-1 card and use it as two separate drives.

Is it just that Unraid does a better job of managing a RAID-1 array compared to BOSS? Unless UNRAID is doing something sophisticated, I'd think that offloading the computing for the RAID function to the BOSS card rather than the main CPU would provide some overall system-level value. 

On 4/29/2025 at 8:49 AM, JorgeB said:

Unraid should get direct access to the devices

Not having it, can cause issues, with lost writes, etc.

Unraid has all it needs to manage multiple drive configs, a RAID card just adds unnecessary complexity/risks. Don't know about the one you have but some are not "transparent" even in single drive mode which causes the OS to not see the drives as they are, you can run into issues like if that card dies you wouldn't be able to access the drive contents when plugged to another system etc...

I am getting back to expanding the Cache for my Unraid server.

I understand that boards with "built in Raid" are not good for Unraid.

We just need to make the drives available and Unraid will manage them for reliability.

So I'm thinking of eliminating the Dell Boss board (which is limited to scarce SATA M.2 drives), and get something like this:

https://www.startech.com/en-us/hdd/pex8m2e2

and populate it with a pair of 1TB WD Black SN850X M.2 Nvme drives.

How could I transfer the data from the existing SSDs on the DellBoss to this new card?

Mount the new SSDs in USB3 enclosures, and copy from the Unraid SSH root while the VMs are stopped?

Then remove the Boss and install the Startech. What are the steps to cause Unraid to see the drives as Cache, and manage them as Raid 1?

50 minutes ago, timg11 said:

StarTech.com

Dual M.2 PCIe SSD Adapter Card - x8 / x16 Dual NVMe or AH...

Enhance workstation performance by adding two PCIe 3.0 M.2 SSDs (NVMe or AHCI) into your desktop computer

This also mentions sofware RAID, make sure it works without it and the devices get passed through directly to Unraid

After looking around, the Startech pex8m2e2 is surprisingly expensive. Even though the M.2 SATA SSDs are more expensive (compared to similar NVME), the total cost is still lower to go with two M.2 SATA SSDs and keep the Dell Boss card.

So in that case I would follow the procedure linked above.

Between the mover action from cache to array and mover from array back to cache, I'd have some extra steps?

• Stop array, Power down Server

• Remove BOSS card, replace M.2 drives with new drives

• replace BOSS card

• Power Up, Access the System Setup (BIOS/UEFI) During boot, press F2 to enter System Setup. Navigate to Device Settings > BOSS-S1 Configuration Utility.

• Go to 3. Virtual Disk Management: If a RAID 1 virtual disk is configured, it will appear here. Delete the virtual disk to revert the drives to non-RAID (unconfigured) mode, making them independently visible to the OS.

• Start server, boot into Unraid

• Hopefully the new SSDs will show up

• assign it, start array and format new cache device (if needed), check that it's using the filesystem you want (original was BTRFS - assume I keep that?)

• ??? what has to be done to turn the two SSDs into a RAID1 managed by Unraid ??

• Once SSDs on BOSS are acting as a 1 TB RAID1, move data back from Array to Cache

• Click on Shares and change the mover action to move from array to pool for all shares that you want moved back to cache

• • On the Main page click "Move Now" • When the mover finishes re-enable Docker and VMs
  

Can anyone comment or confirm this is the correct procedure?

Edited August 25, 2025Aug 25 by timg11

1 hour ago, timg11 said:

??? what has to be done to turn the two SSDs into a RAID1 managed by Unraid ??

It's the default if you assign two devices, with btrfs or zfs.

Jorge, I followed the procedure above. I swapped out the original SSDs with new 1T M.2 SATAs. I put the BOSS board back into the T440 and booted into the BIOS. I deleted the Virtual Disk, leaving the two drives as independent. I started Unraid, and the BOSS card was invisible. The two WDC drives were not seen at all .

Needing to get the server back online, I went back into the BIOS and re-created the VM. Then I restarted Unraid, and it the BOSS was visible again under Pool. But is showed it as "Wrong" and still showed the former BOSS 240G as "missing".

Based on other posts here, I created a new Pool device called newcache with the new device "DELLBOSS_VD_3d884175dfb60010 - 1TB (sdg)" . I deleted the original cache with the BOSS 240G. That got rid of the "wrong" error.

But now for newcache, the status on Main says Filesystem is btrfs. But it also says Unmountable: No File System.

On the details page for newcache, file system type is btrfs, but grayed out.

How do I correct the file system issue so I can move the Pool devices back from Array to Cache?

Edit - I found the format button under Array Start. I was concerned about the stern warning, but since it said it would only format unmounted drives, and all of the array drives were mounted, I went ahead and did it. It seems to have formatted. Now Newcache is showing used and free, and no error.

So I'm configuring the primary secondary for the pool shares to use newcache instead of cache, and reversing the mover direction from Arrary to Cache.

Edit2 - After the mover worked to move from Array to Newcache, I was able to re-enable and start the VMs and Docker containers.

So it's unfortunate the DellBoss card doesn't allow me to let Unraid manage the two drives without doing its own RAID, but at least I have it working again, and have more space to grow with more Docker containers in the cache pool. That's enough panic and stress for one day....

Edit3 - I notices that all the Newcache shares now have a yellow exclamation that says "Some or all files unprotected". I saw this thread, but in that case the issue was files from another cache. I have only one cache, Newcache with the DellBoss SSD. What should I look for to solve the issue?

Edited August 30, 2025Aug 30 by timg11

13 hours ago, timg11 said:

I notices that all the Newcache shares now have a yellow exclamation that says "Some or all files unprotected".

That is normal if you have files for that share on a single device pool, since it will not be protected if a device fails.

@JorgeB Thank you for your help. I finally got the storage expanded in the VM. It's disappointing the BOSS card didn't allow the SSDs to run under native Unraid control, but I was able to expand the space to use the new drives.

That was just the first step in a more complex process, because the Windows VM recovery partition had to be moved to the end before I could expand the data partition. That required booting into Image For Linux, which meant mounting a new CDROM ISO in the VM, which had its own complications with IDE/SATA issues. The boot order must be adjusted in the VM settings since it is impossible to get an F12 keystroke through VNC before Windows starts booting.

Once I got the partitions arranged and expanded, Windows was able to see the larger drive.