what triggers Drobo to self parity check a file?

Hi guys, i was just wonder this…

when exactly does a Drobo (v1/v2 for example) actually compare the file with what is on the Disk Pack overall as part of its self checking?

Assumption scenario:
a Drobo v1, the same hard drives used (size/model etc) (all 4 slots used)

  • windows using the latest droboshare and firmware as of feb 2011

If a file is opened (say a picture), does drobo self-check it upon read of the 1st drive its on, and then check against all other blocks for that file on the other drives, and then open the file for you?

or is it just when a file is written, when it updates the other drives and checks?

theres probably a lot of (cryptic) info merged into the lengthy patent notes when it was filed on google etc, but knowing a lot more about how and when the drobo will do certain things, will help a lot in terms of doing things on the computer.

eg, to help plan out virus scans, cathy database updatings, checksum operations etc.


Typically, RAID checks parity data only to recover from read errors. In other words, parity is unused until it is needed.
Drobo appears to work the same way: there are stories of failed blocks (UREs) being discovered during a rebuild.

See also this thread: http://www.drobospace.com/forums/showthread.php?tid=655

thanks rdo