Expanding hardware RAID without reboot

[mrmvd]

Hello everyone.

I have an Adaptec 8405 hardware RAID controller and a DSM 6.2 for ESXi 6.7. I create a hardware RAID volume (yes, I know that DSM works better with its own volumes, but that's not about it now) and send a 1.07 Tb array to the DSM via RDM. When I add more disks to the array and Adaptec expands the volume to 2.7 Tb, Xpenology continues to see the old volume of 1.07 Tb without rebooting, although both the Datastore and the RDM file already have a new size of 2.7 Tb. The ESX documentation says that in such cases it is necessary to rescan the disk volume in the operating system itself, but I do not know how to do a rescan in DSM.
 

Tell me, who dealt with a hardware RAID under the DSM, how can you expand the array without restarting the DSM?

[flyride]

This is a very good reason why you don't want to do it with a hardware RAID volume.

 

https://xpenology.com/forum/topic/14091-esxi-unable-to-expand-syno-volume-even-after-disk-space-increased/

[mrmvd]

So far, I have decided that it is most convenient to divide the RAID volume into virtual disks and assemble JBODs from them inside the DSM. When increasing the RAID array (which is also a very long operation), you can simply add a new virtual disk to the JBOD that occupies all the free space of the new array.

 

Unfortunately, DSM 7.1 does not work very well with the number of disks greater than 16, all these problems with Sataportmap do not allow us to think that in the future, with the restructuring of the disk system, DSM 7.1 will not fail and will not be blocked.

 

With hardware RAID, there is a problem with parallelization of write operations, which software RAID does natively by the number of disks, but fundamentally the writeback cache increases the write speed to comparable levels.

[flyride]

8 minutes ago, mrmvd said:

Unfortunately, DSM 7.1 does not work very well with the number of disks greater than 16, all these problems with Sataportmap do not allow us to think that in the future, with the restructuring of the disk system, DSM 7.1 will not fail and will not be blocked.

 

Anyone who thinks there is a guaranteed upgrade path to new DSM versions via XPenology should spend some time reviewing the FAQ and the support for prior DSM versions.  Regardless, I don't think this is a reason to compromise the DSM installation you have and are using now.  But to each their own.

 

With direct access to disk devices, DSM offers valuable features that hardware RAID simply cannot do, including proactive device management and repair, dynamic btrfs fire corruption repair using redundant information within the array, and RAIDF1.

[mrmvd]

You are absolutely right, but in my case, hardware RAID is an additional layer of abstraction for DSM, with which I want to avoid possible tripping it on disks.