Yes, you should be able to read and write data to the disk pools. However, it does impact the overall performance of the array.  Before you start the Defrag you need to Determine how much space in a Disk Pool/RAID Group is unusable.  The amount of unusable free space is Free Capacity minus Largest Contiguous Free Space. If the Free Capacity is at least as large as the total user space on all the Virtual Disk that you want to bind on the Disk Pool/RAID Group, then the Virtual Disk/RAID Group has enough space to bind the Virtual Disks. However, if Largest Contiguous Free Space is less than the total, you do not have enoughspace available for the Virtual Disks, and you need to defragment the Disk Pools.  Also do note, Defrag makes all Virtual LUNs on the Disk Pool contigious, thereby removing any unused space between Virtual Disks. Defrag does not degra files on the Virtual Disk as the storage systtem is not aware of filesystem structure (Storage System uses block level) on any host Vitual Disks.
We have an AX150 and it reports that the disk pool is fragmented. Given that it is not possible to stop a deframentation once started, I am concerned that we won't be able to access data whilst the process is running. Can anyone tell me whether we can still read and write data to the disk pool (VDs) whilst defragmenting? I have searched the help available and it does not appear to mention this.  TIA  Charles
Is Defragmenting an AX150 an On-line Operation?