Q: When I tried drag and drop or copy and paste the server started transfer/copy then reboots/freezes/hangs. Is there a way to fix this?
A: This can happen if you share / (root directory). The root directory should not be shared!
Other than that, memory is most likely the problem. Either too little or bad/damaged. If memory is OK, check power supply & motherboard next. References: –dead link {Freenas Rebooting!} – & –dead link {[SOLVED] Hangs and/or Reboots copying files from Windows PC} –. Also check temperatures, make sure nothing is overheating in the system.
If memory is sufficient, PSU, MB all test good, then it could be a hard drive or controller problem; see –dead link {SIL 3114 SATA controller problems} –]] or –dead link {SIL 3124 RAID} –.
Check the MotherBoard BIOS settings for the hard drives. Reference: –dead link {[SOLVED] Server freezes/hangs on large file transfers.} –
How did you format your hard drives? Unpredictable behavior like this can occur if you are using FAT or NTFS formatted drives in read / write mode.
Finally one or more of your UFS file systems may be damaged or corrupt as shown in –dead link {[SOLVED] Rebooting on file copy due to file system damage.} –, try fixing the damage with fsck. If you don't know what fsck is please search the FAQs to learn more about it.