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[nickCR]

Hello All,

I'm having a problem with my DNS-323. It seems that every 2 to 3 days I get a purple light on the right side (slot 2 I believe). I go into the admin and look at the Tools / Raid page and it says "RAID DEGRADED". I have auto re-build off so I am able to rebuild the drive and it continues to work for another 2-3 days before going purple again.

What could be causing this?

1    WDC    WD10EADS-00M2B0    WD-WMAV50176000    1000 G    
2    WDC    WD10EADS-00M2B0    WD-WMAV50146861    1000 G

Forgot to mention i'm running Firmware 1.07

I didn't buy this little guy to have these sorts of problems. Rather I bought it so that I can have a centralized place to store data on the network.

More then anything I wanted this to store media, important files and daily backups of files from my computer. Is RAID 1 not a good choice? Is there a better choice for data redundancy? I cannot have a backup of everything on the NAS on my computer since the size of the NAS exceed my computer space.

So far I haven't put any important data on the NAS since i'm having these problems. I don't see any type of backup system on the NAS that would allow me to have two completely seperate drives and have them mirrored every night.

Also the BitTorrent is ok, but there are some features that I wish it had like a download queue where we could say that we only want one active torrent downloading at a time etc... Ofcourse some method of prioritizing the queue. Is there some type of third party app that I could install to do this?

Thanks in advance.
Nick

[hilaireg]

I'm having a problem with my DNS-323. It seems that every 2 to 3 days I get a purple light on the right side (slot 2 I believe). I go into the admin and look at the Tools / Raid page and it says "RAID DEGRADED". I have auto re-build off so I am able to rebuild the drive and it continues to work for another 2-3 days before going purple again.

The HDD in that slot is failing.  Have you downloaded the HDD Manufacturer diagnostic tool and verified the HDD(s) before using them?  Additionally, verify that the firmware of the HDD's is up-to-date.

Rather I bought it so that I can have a centralized place to store data on the network.

... Is RAID 1 not a good choice? Is there a better choice for data redundancy? I cannot have a backup of everything on the NAS on my computer since the size of the NAS exceed my computer space.

RAID solutions are intended to provide real-time redundancy for disk sub-systems.  When a disk fails, the administrator has an "grace" window to perform and emergency backup, take the unit offline, replace the failed member, and initiate a RAID rebuild. 

Professional RAID solutions provide Hot Spare capabilities where the RAID sub-systems immediately "fails over" to the spare disk, notifies the administrator, and rebuilds the RAID.   Upon notification, the administrator immediately elevates backup priority on that device.

So far I haven't put any important data on the NAS since i'm having these problems. I don't see any type of backup system on the NAS that would allow me to have two completely seperate drives and have them mirrored every night.

RAID1 (mirroring) ensures that both HDD's are synchronized in real-time and as previously noted, is not a replacement for backups.  If the data is important (aka mission critical), you will need to use a backup application (or other solution) to copy the contents of the DNS-323 volumes on a nightly basis.


I own two (2) DNS-323 in RAID1 and two (2) DNS-343 in RAID5; I perform an incremental backup of the data of them nightly.

HTH,

[nickCR]

Thanks a lot for your reply. What app do you use for backup?

I will check the HD and if it's bad i'll have it replaced. I'll also make sure the Firmware on both drives is up to date. Silly I shoulda bought an extra drive as a spare

[hilaireg]

I've have it scripted with some command line tools as I backup to a tape library. 

The DNS used to ship with an AutoBackup utility ... I haven't tried it personally, but it may be suitable.

Cheers,

* EDIT *

Don't know if this may be relevant, but most certainly worth the read:

http://forums.dlink.com/index.php?topic=6568.0

[nickCR]

Thanks for your reply.

I was looking around today and came accross fun_plug which has a nice script to backup everything from Volume_1 to Volume_2 maybe this is a better solution for me.

I do not use my DNS-323 as a real-time storage device. Rather I backup my mailboxes there and other files that I feel are important once a day, usually later at night.

Since inserting the drive 2 days ago I haven't run into any problems... If it fails again i'll plug it into my computer. This will still give me access to my data since it's in RAID1 and honestly that's all that matters

I am curious though. Why is RAID1 not considered a valid backup system? I mean really it's a real-time mirror. The only problem that can really compromise the data is corruption of the RAID1.

Nick

[hilaireg]

RAID1 (aka mirror), or RAID5 for that matter, offer real-time redundancy of data.  Backups are always required however; here are a few reasons why:

• The RAID hardware backplane can fail
• Certain types of disk corruption are not detected as a failure (ex: bad sector) and are mirrored across the array resulting in potential corruption of data
• Accidental modification/deletion of a file
• Catastrophic failure of a disk which necessitates replacement of the failed disk (member); once restarted, the system is unable to rebuild the array and/or an unexpected system error occurs resulting in complete loss of the array volume
  
• Firmware upgrade (hard disk, RAID backplane, etc.) that goes horribly wrong

I've experienced these types of problems on RAID1, RAID5, and RAID10 sub-systems.  Needless to say, had I not had a backup ... valuable (critical) client data would have been lost. 

Without RAID, loss of data is typically from the point of the last backup.  With RAID and depending on backup practices, the potential loss of data can vary: from no loss, a few hours, an entire day, or since the last backup.

In Small Office Home Office (SOHO) use, the RAID solutions are meant to offer some form of data protection - the assumption is that data recovery is all that is required.

In businesses however, the entire server is often on a RAID (O/S, Applications, Data).  This is done to ensure that users experience minimal downtime and minimal loss of data.  Recovery from offline media (tape, etc.) or rebuilding a server from ground up is a lengthy process.  Additionally, any seasoned IT professional will tell you that rebuilding a server from ground up is an absolute last resort as in most cases, a tracking document detailing all of the server configuration changes is not available.

Lastly, assuming the restoration is successful; some server applications (ex: mail servers, database, directory services) require resynchronization before they can return to real-time operation ... all these things can translate to significant downtime.  So RAID'ing such systems often translates to significant cost savings from a professional services point-of-view.


Now for the short answer ... usage of RAID and/or backups greatly depend on how valuable one considers their data to be.  The more valuable, the more protection.

Cheers,

[gunrunnerjohn]

I have a simple reply to such questions.

Remember: Data you don't have at least two copies of is data you don't care about.

RAID is not backup, it's really as simple as that.

[nickCR]

hilaireg thank you very kindly for your reply. That was very in-depth and complete reply thank you.

I am SOHO. Although the thought of having the data redundancy is nice it's not necessary. In the sense that I don't think I need RAID I would probably be just as happy with two volumes where vol 1 is copied to vol 2.

[amunoz_tico]

Mae...

Don't use RAID-1.. try to copy all data from Vol_1 to Vol_2.. Here is a guide that could help you.

http://wiki.dns323.info/howto:backup


Regards!

[gunrunnerjohn]

Good idea, but I suspect many neophytes would go down in flames trying to make this work! 

[amunoz_tico]

Good idea, but I suspect many neophytes would go down in flames trying to make this work! 

Yes, it's true.  I could be not easy... but he has to try... However, the process is very explicit and there are a lot of posts that could help.

Here is other post -> http://forum.dsmg600.info/t1150-Tutorial%3A-Backup-Everything-from-once-night.html


Regards!

[amunoz_tico]

Now, there is a external option to make the backup from Vol_1 to Vol_2.  This one requires a computer.   Yes, yes, yes, it is not a internal solution, but it could work !

Download a free backup software as "SyncBack Freeware".  Here it is =>  http://www.2brightsparks.com/downloads.html#freeware.   Install the software, create a job (profile) and schedule it to run once at day.

[gunrunnerjohn]

I personally use Beyond Compare, but it's a pay program.  I have used it for years, and I am familiar with it, so I stick with it.

[maestro]

for 'syncback' and 'beyond compare'; does it copy round-about from NAS to PC then to backup device?  it doesn't go direct from NAS to backup device if it's not a PC right?

[gunrunnerjohn]

Correct, any backup application running on your computer will move from the backup device to the computer, then back to the destination device.

Since it's all gigabit, and the devices are separate, that doesn't impose any significant performance penalty, at least in my instance.