DSM-G600, DNS-3xx and NSA-220 Hack Forum

Hey guys, new DNS-323 owner here.  I tried the following with the unit.  My conclusion is JBOD is not safe.  If one disk dies for any reason you will loose the data on both disks.

I formatted two 500GB SATA drives with a 160GB RAID 1 partition and the remainder as JBOD.  Put several files on each partition.

I removed both drives and installed them on my PC (Winders XP) and used the windows EXT2 IFS.  There were three partitions on both drives, a swap space, the RAID space, and the JBOD space.  The Swap & JBOD partitions were innaccessable.  Only the RAID partition had files on it.  This was true for both drives.

Next I installed both disks back in the DNS and verified both the RAID1 & JBOD were still functioning (they were).  Then I powered down and removed the right hand drive, and repowered the DNS323.  The RAID continued to function but the JBOD was innaccessable.  When I powered down and re-insterted both drives, the JBOD partition CONTINUED TO BE INNACCESSABLE.

So, not only is the JBOD susseptable to drive failures, but it would seem it is prone to other hiccups (such as powering on one disk due to perhaps a connection problem or controller failure) as well.  The result of which is you will loose everything.  Keep a good backup!

n0m0r3 wrote:

the reason why it is not working for you is because you configured RAID 1, I believe if you just configure JBOD you will have a failsafe situation

What would you consider a "failsafe" situation ?

JBOD - in this case - concatenates the partitions to form a single large one, and writes data first to one partition and when that is full, switches to the second.  Theoretically if the disk holding either partition fails the data on the remaining partition would be available - BUT - I have yet to hear from anyone for whom this worked in practise.

To all intents & purposes there is NO failsafe with RAID0 and concatenated JBOD and these should not be used for data storage as failure of any of the drives is pretty much guaranteed to cause the loss of stored data.

Why would they exist if this is so and what should they be used for?  Temporary storage of non-critical data, swap files, print spooling, etc.

No offense meant - but that was a specific question to a specific user - I want to know what he meant, and not really another person's interpretation - it's not that I don't welcome your contribution - your view on the issue is always welcome, but your interpretation of his post may or may not be accurate.

My view is essentially that JBOD & failsafe should not be mentioned in the same sentence unless it is structured similar to the statement below, which is quoted from an earlier post.

To all intents & purposes there is NO failsafe with RAID0 and concatenated JBOD and these should not be used for data storage as failure of any of the drives is pretty much guaranteed to cause the loss of stored data.