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[loloaqic]

The time has come to upgrade the storage in my DNS343. I am currently running a RAID1 across two 2TB HDDs.
These present a single share point to the network. I am looking for feedback from the DNS community, that may prevent me from making a complete hash of what currently works fine.
1. Can I add two more 2TB HDDs, and extend the existing RAID1 onto them?
2. Could I backup my existing RAID1 data, then delete the existing RAID1, install my 2 new HDDs, create a RAID1 across all four 2TB HDDs to deliver 4TB, restore my data? (may also have to recreate user&group permissions along the way)
3. Some other suggestion from those out there who know far more than I do?

Looking forward to a flood of suggestions. 

[JavaLawyer]

1. Can I add two more 2TB HDDs, and extend the existing RAID1 onto them?

The DNS-343 supports neither changing RAID type nor expanding the number of HDDs in a RAID without a complete reformat and loss of data.

2. Could I backup my existing RAID1 data, then delete the existing RAID1, install my 2 new HDDs, create a RAID1 across all four 2TB HDDs to deliver 4TB, restore my data? (may also have to recreate user&group permissions along the way)

From your post it looks like you are trying to create a RAID 10 configuration. The DNS-343 manual describes a "RAID 1 + JBOD" option. See the advanced configuration discussion in the DNS-343 manual. I haven't used this configuration myself, nor do I recollect any pertinent discussions on RAID 1 + JBOD on this board, so I can't comment on how well this configuration will work.

3. Some other suggestion from those out there who know far more than I do?

Conceptually, a RAID 1 + JBOD configuration should be more secure than a traditional RAID 10, since one failed HDD in one of the mirrors will not result in a complete data loss of the failed mirror. That said, many users on this board shared unfortunate experiences with RAID implementations on this device, and IMHO creating a multi-layered disk configuration only compounds the issues that could arise if something goes wrong. When RAID works on the DNS-343, it works great, but when it breaks down, a number of owners have experienced catastrophic issues during rebuild attempts, while others have had no issue whatsoever. You'll have to weigh the pros and cons for yourself.

My one adamant piece of advice is that since RAID is NOT a backup, and you should maintain a separate physical backup of your data at all times. This strategy is not only prudent, but will ensure the security of your data in the event your RAID configuration breaks down.

Data Backup vs. Redundancy

[loloaqic]

From your post it looks like you are trying to create a RAID 10 configuration. The DNS-343 manual describes a "RAID 1 + JBOD" option. See the advanced configuration discussion in the DNS-343 manual.

RAID10, Quite correct. and having read the "sketchy" information you pointed me at, I'm happy I know what to do.

I too have been caught many times without adequate backups. I not only have backups copies (taken regularly) at home, but also OffSite. I also understand that all RAID1 or RAID5 will deliver is a guard against a single (and maybe a double in a 4HDD RAID1... if I'm lucky) HDD failure.

[JavaLawyer]

RAID10, Quite correct. and having read the "sketchy" information you pointed me at, I'm happy I know what to do.

I too have been caught many times without adequate backups. I not only have backups copies (taken regularly) at home, but also OffSite. I also understand that all RAID1 or RAID5 will deliver is a guard against a single (and maybe a double in a 4HDD RAID1... if I'm lucky) HDD failure.

If you decide to move forward with the RAID 10 (RAID 1 + JBOD) please post your experiences.
Thanks. . . .

[loloaqic]

If you decide to move forward with the RAID 10 (RAID 1 + JBOD) please post your experiences.
Thanks. . . .

Will do.
BTW, my understanding is RAID10 is a combination of RAID1 built on RAID0. This is NOT what I understand RAID1+JBOD to be. Since JBOD is different from RAID0.
However, as RAID10 is not offered on the DNS343, RAID1+JBOD is preferred to RAID5 (personally speaking).

[JavaLawyer]

RAID 1+0 should provide improved performance over RAID 1+JBOD, since RAID 0 stripes data, while JBOD simply provides a single contiguous storage space across multiple drives.

As you aptly pointed out earlier, the manual is kind of kludgy when describing the RAID configurations. I don't quite understand why RAID 1+0 is missing, while offering RAID 1+JBOD (which I've never seen before purchasing the DNS-343.

[loloaqic]

Have you any advice on how I "tidily" remove the RAIDset?

[JavaLawyer]

Have you any advice on how I "tidily" remove the RAIDset?

Please see your other thread: Downgrading

[loloaqic]

If you decide to move forward with the RAID 10 (RAID 1 + JBOD) please post your experiences.
Thanks. . . .

I tackled "support@dlink.com.au" for information on how a RAID1 set was treated. Their response has floored me. They state that a RAID1 set built on 4 x 2TB HDD's will deliver 2TB. They state that HDD1 is mirrored to HDD2, HDD3, and HDD4.
 

I was expecting to have 4TB. Has anybody configured a RAID1 set across 4 drives, and can confirm the statement from support?

[JavaLawyer]

I tackled "support@dlink.com.au" for information on how a RAID1 set was treated. Their response has floored me. They state that a RAID1 set built on 4 x 2TB HDD's will deliver 2TB. They state that HDD1 is mirrored to HDD2, HDD3, and HDD4.
 

I was expecting to have 4TB. Has anybody configured a RAID1 set across 4 drives, and can confirm the statement from support?

I believe D-Link AU is referring to a nested RAID-1 array (RAID 1+1), where a RAID-1 array is created from two RAID-1 sets. This approach is the only way to achieve an effective usable storage capacity of 2TB (with 4, 2TB HDDs)

• RAID-1 set 1 (slots 1/2, HDD1 mirrors HDD2, 2TB of usable storage)
• RAID-1 set 2 (slots 3/4, HDD3 mirrors HDD4, 2TB of usable storage)
• RAID-1 set 3 (RAID-1 set 1 mirrors RAID-1 set 2, 2TB of total usable storage)

If you configure two RAID-0 sets OR two JBOD sets AND configure a nested RAID-1 array (RAID 1+0 or RAID 1+JBOD), then the usable storage capacity will be 4TB

• RAID-0 set 1 (slots 1/2, 4TB striped across HDD1 and HDD2)
• RAID-0 set 2 (slots 3/4, 4TB striped across HDD3 and HDD4)
• RAID-1 (RAID-0 set 1 mirrors RAID-0 set 2, 4TB of total usable storage)

OR

• JBOD set 1 (slots 1/2 4TB of contiguous storage across HDD1 and HDD2)
• JBOD set 2 (slots 3/4 4TB of contiguous storage across HDD3 and HDD4)
• RAID-1 (JBOD set 1 mirrors JBOD set 2, 4TB of total usable storage)

[loloaqic]

Oh the disappointment...
I purchased the 3rd and 4th 2TB drives today, and ran home to blow away the existing 2TB RAID1. I asked it to build me a RAID1 configuration and the results are NOT what I expected.

I expected a single Volume_1 of 4 TB.
What I ended up with was a Volume_1 of 2TB, and a Volume_2 of 2TB.

My DNS-343 has 1.04 firmware, and unless someone can confirm that the 1.05 beta will fix this for me I am reluctant to use beta code.

If someone has worked how to resolve this can you please post a reply?

[JavaLawyer]

Here's a thread that may provide a workable solution to your dilemma: 343 with 2 R1 volumes - is there an "official" way to do this?

Please post if/after you've try the procedure in the above thread.

[loloaqic]

Here's a thread that may provide a workable solution to your dilemma: 343 with 2 R1 volumes - is there an "official" way to do this?

Please post if/after you've try the procedure in the above thread.

Sorry to say but that thread talks about how to create 2 RAID1 volumes across 4HDDs. I want to create 1 RAID1 volume across 4HDDs such that I get the volume set to the size of 2 of the HDDs. For example, across 4 2TB HDDs, I would get a single 4TB volume.
BTW, I have had no difficulty creating 2 RAID1 volumes across 4HDDs.

[JavaLawyer]

Sorry to say but that thread talks about how to create 2 RAID1 volumes across 4HDDs. I want to create 1 RAID1 volume across 4HDDs such that I get the volume set to the size of 2 of the HDDs. For example, across 4 2TB HDDs, I would get a single 4TB volume.
BTW, I have had no difficulty creating 2 RAID1 volumes across 4HDDs.

I understand now. It looks like we had a disconnect.  The only way to achieve the results you are looking for is either JBOD+RAID1 (two JBODS in RAID 1) or RAID 0+1 (two RAID 0 arrays in RAID 1)

[loloaqic]

I understand now. It looks like we had a disconnect.  The only way to achieve the results you are looking for is either JBOD+RAID1 (two JBODS in RAID 1) or RAID 0+1 (two RAID 0 arrays in RAID 1)

Do you believe that the DNS343 is capable of being configured as a (two RAID0 arrays in a RAID1)?
Because I cannot see how to achieve that.