How to expand volume size in DSM 7 installed on esxi?

[W25805]

I set up xpenology with dsm 7 on a dell r730xd server on esxi. I expanded the disk size on esxi and it is reflected in the storage poll but can't expand the volume associated with it. I looked up solutions but most of them are for dsm 6 or lower. The volume is mounted on /dev/mapper/cachedev_0 and when I tried to run mdadm commands, it returns as follow.

sudo mdadm --detail /dev/md2
mdadm: /dev/mapper/cachedev_0 does not appear to be an md device

Can anyone help me with this?

[WiteWulf]

What I would've done is, rather than expanding an existing disk, create a new disk and add it to the existing storage pool, then expand the volume. But as you're using Basic RAID that's not possible. As DSM formats the disks and adds a variety of different partitions to them behind the scenes (and isn't designed to run in a hypervisor environment) I don't think it will allow you to extend virtual disks.

 

It's possible, I believe, to do this on the cmdline, bypassing DSM's Storage Manager, but it's complex (particularly with btrfs) and you risk losing all your data.

 

Looking at your hardware (Dell R730xd ), are you using some sort of RAID with redundancy at the bare metal level and presenting ESXi with one or more large disks? If you're doing that on the bare metal there's no point doing and redundant RAID in DSM as you're wasting disk space.

 

I'd be inclined to:

• in ESXi, shrink the virtual disk back down again (or restore the snapshot you took before extending it (you did take a snapshot, right?  ))
• use the space to create a new virtual disk
• add the new disk to the VM
• in DSM, create a new Storage Pool (this time using a RAID type that you can extend , like JBOD, or something with protection like SHR (not necessary if you're doing some sort of RAID with protection at the hardware level) with the new disk
• create a new volume on the new storage pool

 

[W25805]

Yes, I'm running raid 6 on the r730xd. I was trying to expand the disk through cmdline, but all the instructions were for DSM 6 I think, so they won't work with the new disk partitions in DSM 7. I guess I will just create a new VM with JBOD and sync everything there, delete the existing one and expand the new one. Is there an option to set up JBOD instead of RAID in DSM 7, I forgot whether I saw that option or not.

[WiteWulf]

Yes, you can use JBOD in DSM, but it's referred to as "Basic" RAID.

 

Remember a big limitation of JBOD (that bit me in the arse recently): it has no fault tolerance (obviously), but be aware this means you cannot remove a disk from the array without losing all data.

[cwiggs]

On 10/3/2022 at 1:43 AM, WiteWulf said:

Yes, you can use JBOD in DSM, but it's referred to as "Basic" RAID.

 

Remember a big limitation of JBOD (that bit me in the arse recently): it has no fault tolerance (obviously), but be aware this means you cannot remove a disk from the array without losing all data.

"basic" and JBOD are 2 different types of "raid" levels in DSM.  AFAIK "basic" is actually raid1 just with 1 drive not attached, if you add a 2nd drive later you can attach it and DSM then considers it raid1.