Hello,
If you have a drive failure during an expansion you should take immediate steps to get a full backup of all data on the vdisk. A rebuild cannot complete until the expansion finishes. Without full redundancy your data is at risk.
Vdisk expansion may take a long time and will work in the background letting host IO take presidence over the expansion process. You may wish to consider backing up your data, delete the current expanding vdisk, and create a new vdisk on the size you now need, then restoring data from backup.
Cheers,
Shawn
