i've a NAS with 5 disks in RAID-5. I used it as DataStore for Virtual Box Hard Disk. So i've for example one big (1.5 terabyte) VDI file that contain 200k files. I'm wondering: Is the single file good managed by physical Raid or, for example, my Nas is 'stupid' and save this single file into... a single disk and not 'straied' onto all disks ? Thanks
Most NAS devices use a version of linux with the linux mdadm package to manage the raid, if set up as a raid-5 you will get a situation where blocks are spread across all devices part of the array.
For more information about mdadm: http://en.wikipedia.org/wiki/Mdadm#RAID_Configurations