Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[crgeissler]

I have read it on this forum enough times -- Raid isn't for backup.  Great.  Now, I have a DNS-323 that I want for backup. Here is what I am hoping to do:

A. I  have three 1 TB seagate barracuda drives.
B. I have firmware 1.09 on my DNS NAS
C. I want to setup the two drives as Individual Disks (not JBOD, not RAID)
D. I want to backup every second day to each disk
E. Every week I want to swap the disk on the right with the third disk

I setup the two drives, mounted both volumes in windows, copied one different file to each, then added the third disk.  Everything seems to go fine, but when I add the third disk, the NAS won't mount the drives.  I have done this enough times (but never as systematically as a good scientist would) and I don't know how to get this to work -- so I have to ask ...

Is a two individual disk configuration possible?  Is the three disk configuration possible?

Thanks.

[ivan]

Not a good idea, especially since repeatedly swapping disks will damage the connectors and lead to data loss and possible damage to the disks themselves.  What you are proposing is fine with a tape drive - it's what they are designed to do - but not a NAS, different usage.  Tape - backup, NAS - storage.

RAID 1 produces two identical disks and so covers your point 'D' and also saves having to do the backup twice.  You can then use the third disk mounted in an SATA/USB caddy to backup the NAS.

Now to answer your questions.  Yes it is possible to have two disks as separate volumes as long as they stay in place in the NAS.  Using three disks will NOT work as you propose - use it as a USB backup.

[fordem]

Using individual disks, I had no issues with swapping the disks in & out, but I never did it in any systematic manner, and it was only done with the earlier versions of the firmware.  My shares have been the entire disk and they were never "mounted" in Windows (assigned drive letters) but used with UNC notation.

I also want to point out that the SATA connectors are designed for swapping, including hot swapping (which the DNS-323 does not support) and are used in several removable cartridge backup solutions - take a look at Dell's RD1000 & the Imation Odyssey line - so the connectors should not be a problem - on the other hand - the ability of D-Link's ejection mechanism to withstand the repeated use is unknown.

[ivan]

I also want to point out that the SATA connectors are designed for swapping, including hot swapping (which the DNS-323 does not support) and are used in several removable cartridge backup solutions - take a look at Dell's RD1000 & the Imation Odyssey line - so the connectors should not be a problem - on the other hand - the ability of D-Link's ejection mechanism to withstand the repeated use is unknown.

Agreed, but the quality of the sockets varies greatly - some are excellent and are used in the products you mention, others are not so good and have a limited life if used for repeated connect/disconnect, I know because I've had to replace defective ones.  Somehow I don't think D-Link have used the most expensive ones in a product that is designed to have limited insert/remove cycles.

[JavaLawyer]

Agreed, but the quality of the sockets varies greatly - some are excellent and are used in the products you mention, others are not so good and have a limited life if used for repeated connect/disconnect, I know because I've had to replace defective ones.  Somehow I don't think D-Link have used the most expensive ones in a product that is designed to have limited insert/remove cycles.

Agree 100%. The durability and engineering of a number D-Link products left wanting, partially explaining the relatively low price/feature ratio.

[Newbie06]

To OP,

Why wouldn't just format as RAID to being with and save yourself a bunch of headache?  The chance of failure of both drives at once is, well....very, very slim.  RAID makes it easy for you as well.

It sounds like you aren't looking to gain any disk space in your posted method.  If anything, you are using more disk space to what can be accomplished no two drives with a RAID format.

Just curious...

[fordem]

To OP,

Why wouldn't just format as RAID to being with and save yourself a bunch of headache?  The chance of failure of both drives at once is, well....very, very slim.  RAID makes it easy for you as well.

It sounds like you aren't looking to gain any disk space in your posted method.  If anything, you are using more disk space to what can be accomplished no two drives with a RAID format.

Just curious...

1 - Because a RAID array does not allow the backup to be stored off site - think disaster recovery rather than just backup.

2 - Because a disk failure is not the only cause of data loss.

Disk space is cheap, recreating lost data is not always possible

[Newbie06]

1 - Because a RAID array does not allow the backup to be stored off site - think disaster recovery rather than just backup.

2 - Because a disk failure is not the only cause of data loss.

Disk space is cheap, recreating lost data is not always possible

Good point, yet the OP seems to want to spend a lot of time doing this entire process.  What are the chances of both drives failing in a RAID format and losing all data?  I mean...seriously, what are the chances?

You state disk failure is not the only cause of data loss, what other causes are you referring to?

Disk space is cheap and in most cases time is NOT cheap which brings me back to the point of the OP spending a lot of time doing this and that which can be effectively covered by a RAID format.  Not to mention the additional disk space the OP would have in doing so.

The OP may have another factor as to why he does not want to use RAID format which is why my questions were initially directed to him and not you.

[dosborne]

You state disk failure is not the only cause of data loss, what other causes are you referring to?

Deleting a file and/or folder by accident?

[fordem]

Good point, yet the OP seems to want to spend a lot of time doing this entire process.  What are the chances of both drives failing in a RAID format and losing all data?  I mean...seriously, what are the chances?

Greater than you would think - I've been a tech support professional for over three decades - the fact that you ask that question tells me that you can't start to imagine what I have already had to deal with.

You state disk failure is not the only cause of data loss, what other causes are you referring to?

Are you serious?  Fire, flood, lightning strike, power surges, riots, accidental or deliberate deletion of files, equipment failure, viruses - I'm sure I've missed a few, but that should give you a general idea - did I not say think disaster recovery?

[crgeissler]

Hi,

The reason I didn't want to go with RAID is because I have been convinced that RAID is not backup.  In the hands of an unprofessional, RAID is complicated and can easily result in data loss -- particularly when auto-rebuild is enabled.

What I want is a device that will be more like a backup system with some built in redundancy -- hence 3 disks.  Two disks that are mirrored (and better yet an incremental backup so accidentally deleted files can be retrieved) and a third disk that is swapped with Disk 2 for off-site backup.

I am setting this up for a small business who *could* use cloud-based storage for off-site backup but the risks with that are:
1. A popular cloud-based storage site seems one security breach away from being sued out of existence which has hurt the reputation of cloud-based storage
2. That same company inadvertently made everyone's data password-free, which would:
a. Expose this company's clients' personal information
b. May result in prosecution under federal privacy laws (or at least a nice, business-killing lawsuit).

The benefit of an off-site backup disk is that in the case of a data breach the company can argue that the data was stored on-site in a secure way and moving a disk off-site is a standard procedure with inherent risks that have been mitigated.  Due diligence was performed.

Thanks for the help.  I have decided to format two disks as RAID 1 and to tape the DNS closed.  I am giving the office administrator a SATA USB dock and some software to run weekly when she brings in the off-site disk.  It will do a differential backup and grab a copy of everything on the NAS that has changed.

I really think there is a market for simple multi-bay backup device, as I have described, for small businesses.

tx again.

[Newbie06]

Greater than you would think - I've been a tech support professional for over three decades - the fact that you ask that question tells me that you can't start to imagine what I have already had to deal with.

Are you serious?  Fire, flood, lightning strike, power surges, riots, accidental or deliberate deletion of files, equipment failure, viruses - I'm sure I've missed a few, but that should give you a general idea - did I not say think disaster recovery?

I have no idea what you've dealt with, only base my questions on personal experience.  I have only lost two hard drives since I have owned a computer.  One on a laptop with no backup, but luckily I was able to get the files off the drive.  Two on my DNS with a RAID configuration.

I have yet to deal with any of those disaster events and I can certainly see your point.

I wasn't quite clear on how the OP was using the backup scenario as he did not clarify if he was storing the third disk off-site, or what not.  If it was stored with the other disks the disaster recovery scenario would be a moot point for a majority of the issues you described anyhow.

It is good to hear this stuff though so I can have a better understanding and knowledge so thank you for your insight.

[JavaLawyer]

Another potential failure point is the malfunction of the NAS hardware, which may not necessarily destroy data, but at the very least would render data temporarily unavailable. I opted to store my primary and backup data on two separate physical devices, with "super critical data" (not a sanctioned IT term ) stored at a remote location.

As someone pointed out earlier, HDDs are relatively inexpensive. Speaking for myself, the technical simplicity of a non-RAID solution and low cost of storage more than outweigh the potential technical issues associated with a consumer-grade software-based RAID implementation. My data is too important to justify the risk.

[domi]

Speaking for myself, the technical simplicity of a non-RAID solution and low cost of storage more than outweigh the potential technical issues associated with a consumer-grade software-based RAID implementation..

Sorry if it's a dumb question (I know next to nothing about RAID), but is RAID as implemented in DNS devices software-based? In other words, it's implemented at the OS level, not in the DNS hardware?

I'm starting to think that RAID isn't perhaps such a great idea in a unit used for backup purposes (as opposed to live data). Do you achieve the desired level of redundancy by backing up to multiple devices, rotating between them?

[fordem]

Sorry if it's a dumb question (I know next to nothing about RAID), but is RAID as implemented in DNS devices software-based? In other words, it's implemented at the OS level, not in the DNS hardware?

I'm starting to think that RAID isn't perhaps such a great idea in a unit used for backup purposes (as opposed to live data). Do you achieve the desired level of redundancy by backing up to multiple devices, rotating between them?

The RAID as implemented in the DNS device is software based, implemented at the OS level.

RAID is always software based, in that there is software controlling it, however sometimes the software is running on a processor dedicated to the RAID, which allows it to be less of a compromise.

Using RAID on a backup device has it's advantages and disadvantages - let me bring one to your attention.  Many of us have switched to disk based backup, primarily because of the cost - however - if the hardware fails it typically takes the data with it, which was not the case with the removable storage devices previously used.

With a tape or diskette drive you could easily have two or three (or more) copies of your data, and if the drive failed you simply put the tape or diskette into a new drive, if the tape or diskette failed you had a slightly older copy you could fall back to.

This is not the case when you backup to an external USB disk, if that drive fails your data is probably gone with it, hence the need for more that on physical copy of the data - or if you like a backup of the backup.