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

Using firmware v1.03

1 - Very likely - provided you have email notifications enabled and working - don't rely on the front panel LEDs to go amber.
2 - easy as 123 - 1 - power the system down, 2 - remove the failed drive, 3 - insert the new drive.
3 - In my opinion not very likely, I've done some pretty through testing of drive failure scenarios and not had it happen once - see #5 below.
4 - No - it is not automatic, after replacing the drive you must log in through the web interface and accept the format & rebuild prompts.
5 - Ensure the replacement drive has no partitions on it and is the same size or larger than the failed drive.
6 - No - it doesn't.

Having said all that - the purpose of RAID is to reduce the impact of downtime when a disk fails.  It is not a subsitute for backup and if you do not backup the data stored on a RAID array (doesn't matter if it's a DNS-323 or another device) you will at some point lose it.

Hi Focker,

So are you saying just put in 2 drives (without RAID1) and manually drop and drag files across every so often?  Is there a script that could be run with Windows scheduler to automate this, if indeed this is the most reliable way to back up?

I could be missing something here...

Chumby

Emacs - thanks very much for the tip.

Hmmm.... dns not funplugged but thinking about it.  Just a bit nervous as I literaly know zip about Linux.  Saying that I would be able to pick up the basics I guess??

So is there any way to automate the copying?  Would I schedule a telnet session (using putty or something) via the windows scheduler which could copy the files on a regular basis?

Are there any example scripts around to have a look at?

Finally, I am presuming NOT to go RAID1 is the way to go - just do this manual copy idea.

Thanks heaps for the help.

Cheers,
Chumby.

Emacs - thanks heaps for the info on this.  Yea, I can see the advantages over RAID1.  I wonder if you would need to delete evreything on Volume_2 before the copy over, to ensure their are no files that you wanted to delete on Volume_1 still hanging round on Volume_2 from a previous backup.

What about copying to an attached storage device instead of Volume_2.  Would that have any advantages?

Chumby

Brent212 wrote:

fordem wrote:

the purpose of RAID is to reduce the impact of downtime when a disk fails.  It is not a subsitute for backup and if you do not backup the data stored on a RAID array (doesn't matter if it's a DNS-323 or another device) you will at some point lose it.

Assuming you never had a time where both drives failed before the array could be rebuilt, could you still lose data? If so, how?

Ever had a user delete a file - either deliberately or by accident?  Ever had a virus corrupt your files?  Ever had an application crash and corrupt it's data files?

With RAID whatever happens, happens to both copies of the data at the same time - if you don't have a backup, your data is GONE - if you have a backup, you can restore from that backup, however depending on the time interval between the backup and whatever destructive event occured you may lose data, but rekeying a day's worth of transactions is a lot less traumatic than rekeying a month, and backup strategies can (and should) be developed to minimizes that data loss.

The short answer is no - I know just enough linux to be dangerous, but not enough to be useful - but - I would guess RSYNC to do the copy (if it's available) and some sort of CRON task to automate it, just don't ask me how.

Thanks for the Fordem and Skydreamer...

Just to make it clear - (newbie here)...

I have installed funplug and I can telnet to my dns.  That bit is OK... however...

What step by step process do I go through to get everything from volume_1 to volume_2 (deleting everything off volume_2 first) say once a day at night. (Sorry Skydreamer if this is really basic - I am new to all this...)

You guys are great....

Cheers,
Chumby

I've encountered an interesting variant of this problem. I'm using 2 Hitachi's 1TB drives. Because I needed more space before my DNS-323 arrived, I copied a bunch of data to one of the drives. I called tech support (waste of time) to confirm that I could load 1 drive (left bay as depicted in the manual), copy the data to it, load the 2nd drive, and configure it for RAID 1.  WRONG!!!

I ended up with a JBOD and too much data to offload and start the process over.  The system didn't give me the option to format the 2nd drive for RAID1.  After the format was complete, in order to convert to RAID 1, I'd have to erase EVERYTHING. I've also ended up with Volume_1 mapped to /mnt/HD_b2 and Volume2 mapped to /mnt/HD_a2!  I would recommend updating the FAQ to warn people to put the first drive in the the RIGHT side first.

Questions:
- Any ideas on how to remap Volume_1 back to HD_a2 (as per the std config) and Volume_2 to (HD_b2)?  Do I need to swap the drives?  Is there chance for data loss....OK OK...so I need to purchase a THIRD USB drive to back this sucker up.

- Now I'm thinking an rsync CRON job that copies data from Volume_1 to Volume2 (with Volume_1 treated as the primary) might meet my needs better. Granted, this doesn't save me from 24 hours of data loss if a drive dies, but it does give me 24 hours of recoverability!  Plus if the DNS freaks out, I can use std UNIX tools to access either drive without dealing with any funky RAID setup.

- Anyone setup the BackupPC program using the DNS-323 as a server to perform remote backups and system mirroring?

skydreamer wrote:

This should work if you can get your hands on a full version of rsync

rsync -rlptDv --delete  source_dir destination_dir >log_file


I used it for backups on FC6.

However trying to replace broken RAID1 functionality with rsync is not the way to go.

Hi skydreamer - how is the RAID1 functionality broken on the DNS323?

Also, thanks to everyone for adding to this thread.. these are issues that I wanted to hear some opinions on before I pulled the trigger and buy a DNS-323!

dan.crouthamel wrote:

Focher wrote:

Fonz recommended what I think is the best approach regarding the DNS if you are thinking of RAID1. Just format the drives separately and periodically backup one drive to the other. Considerably more reliable if you ask me.

I agree, and that's exactly what I'm doing with my DNS.  On top of that, that data is being synced to another drive on a windows machine.  I hope to avoid that part by reading up on the HowTo for attaching an external USB drive, so I don't have to sync data over the network.

But then if a file becomes "corrupted", isn't there a chance that you'll be backing up that corrupted file and losing a good version of it? Not sure how it happens, but in the past I've opened up a video file to discover that half of the movie is missing. If I just formatted my backup drive and copied everything to it, I'd now have two copies of that screwed up video file. Incremental backups seem to avoid this, although I'm not positive about that.

I'm just using rsync to keep data in sync across the 2 drives.  That's good enough for me

Chumby wrote:

Dan,

Thanks for that.  For the newbies here... how do you run rsync?  Do you automate that on a daily basis or something?  Is it automatied through the DNS scheduler, or windows?

Cheers
Chumby.

The hard way - manually   Just telneting into the device and running it from the command line for the directories I really care about.  I'm looking into something more automated, but for now this will work.