Mixed RAID with two drives

[Vad1mo]

Hello,
I am planning to buy a DS213+ NAS with two 4TB drives. The NAS will be used to store some "valuable" data and a bunch of movies that can be ripped again.

My ideal solution would be to have RAID1 for the first 2TB of each disk and JBOD for the other 2TB. This would result in 6TB total available space.

So the question is:
1. Can it be done and what is the naming for this type of RAID?
2. Can mdadm do it?
3. Can Synology DSM do it out of the box?

Cheers,
Vadimo

 

[thiggins]

What you are describing would involve multiple volumes, not a RAID type. I don't know if you can have multiple volumes on the same drives.

 

[TonyH]

Hi,
As far as I know answer is no. Raid 1 is not bullet proof way of keeping data. Really back up should be done independent of Raid set up kept away safe. I have DS713+/DX213 but
most important back up is done on another hard drive and tape thru USB3/SCSI hook up for safe keeping.

 

[stevech]

That's what I do with my 2-drive NAS.
Drive 1 is volume 1, 2 is 2. Independent volumes, file systems.
Data on 1, backup of 1 on 2, plus time backup (document versions) on 2.

And a copy of 1 on a USB3 drive, except for low importance folders like my drive images from PCs.

RAID is not a backup!!

I'd be wary of using 4TB - make sure the the NAS vendor assures compatibility. Or just go down a notch.

 

[whsbuss]

That's what I do with my 2-drive NAS.
Drive 1 is volume 1, 2 is 2. Independent volumes, file systems.
Data on 1, backup of 1 on 2, plus time backup (document versions) on 2.

And a copy of 1 on a USB3 drive, except for low importance folders like my drive images from PCs.

RAID is not a backup!!

I'd be wary of using 4TB - make sure the the NAS vendor assures compatibility. Or just go down a notch.

Getting a DS213 next week with (2) 2TB WD Reds. So I should setup RAID 0, have data on drive 1, set time backup to drive 2. Do you schedule a daily backup or something different.

 

[stevech]

2 drive small NAS.
I use NO RAID. Two independent volumes. The Synology time backup runs every day and updates the versions of files new / changed. The other daily backup sync's key folders on volume 1 to volume 2. And once a week to USB3. All these are automated. Independent file systems.
I did this to get protection from

• drive failure - RAID does this
• file system failure (corruption) - RAID does not do this
• human error - deleted it by mistake. Goofed up my document or spreadsheet- RAID does not do this
• Stolen NAS - RAID doesn't protect. USB3 backup does
• NAS software upgrade hoses up file system. RAID doesn't help. USB3 backup does
• I elected to not use cloud backup. Too slow. And in the US, they must have the decryption keys for court ordered data reveals. Disgruntled employee is the risk.
• I also copy Very VIP folders to a 32GB SD card in the NAS - finances and family photos.
• And I use SecureHouse software to put all financial info in an encrypted virtual drive that is quick to mount/use and auto-dismounts when not in use.

.

 

[whsbuss]

2 drive small NAS.
I use NO RAID. Two independent volumes. The Synology time backup runs every day and updates the versions of files new / changed. The other daily backup sync's key folders on volume 1 to volume 2. And once a week to USB3. All these are automated. Independent file systems.
I did this to get protection from

• drive failure - RAID does this
• file system failure (corruption) - RAID does not do this
• human error - deleted it by mistake. Goofed up my document or spreadsheet- RAID does not do this
• Stolen NAS - RAID doesn't protect. USB3 backup does
• NAS software upgrade hoses up file system. RAID doesn't help. USB3 backup does
• I elected to not use cloud backup. Too slow. And in the US, they must have the decryption keys for court ordered data reveals. Disgruntled employee is the risk.
• I also copy Very VIP folders to a 32GB SD card in the NAS - finances and family photos.
• And I use SecureHouse software to put all financial info in an encrypted virtual drive that is quick to mount/use and auto-dismounts when not in use.

.

I like your configuration for sure. I do a similar thing with the MyBook live NAS I'm looking to replace. I do a scheduled weekly rysnc (safe point) to a USB drive. My one question is why do you run sync on key folders when the first backup you mention would already cover that?

 

[stevech]

sync backup from vol 1 to vol 2 is key folders only because there are lots of GB of drive images from other PCs. No need to backup those.

The time backup - keeps prior versions for certain folders. A few times this has helped me get a file back that I've hosed up.

The USB3 backup is in ext4 format. I use "disk Internals Linux" to read ext4 under windows 7, 64 bit. I used to have the USB3 drive in NTFS format, but it's a lot slower than ext4.

It may be that today, the greatest risk to our NASes (and computers) is grab-and-go theft, not technical faults.

 

[sfx2000]

Hello,
I am planning to buy a DS213+ NAS with two 4TB drives. The NAS will be used to store some "valuable" data and a bunch of movies that can be ripped again.

My ideal solution would be to have RAID1 for the first 2TB of each disk and JBOD for the other 2TB. This would result in 6TB total available space.

So the question is:
1. Can it be done and what is the naming for this type of RAID?
2. Can mdadm do it?
3. Can Synology DSM do it out of the box?

Cheers,
Vadimo

RAID does not resolve you of backups for data that cannot be replaced.

Recommend RAID5 across the discs with multiple sharepoints - and have a backup solution for the sharepoint that requires things to be permanent.

MDADM can do this - not sure about this box and it's GUI - but just basic common sense.

sfx

 

[Vad1mo]

My final solution

So the question is:
1. Can it be done and what is the naming for this type of RAID?
2. Can mdadm do it?
3. Can Synology DSM do it out of the box?

I am still not sure if my initial idea would work or no. I didn't give it a try. I came to a another conclusion after all.

My precondition is that I can live with the fact that if a drive fails my system I can not access my data immediately and need to restore them.

So the conclusion for me is that a backup solution would fit my case better than a fail over solution (this is basically what RAID stands for).

Currently I just backup my files to the second drive every day. If drive 1 gets full and I need drive 2 to store data I am going to connect an external ESATA drive to backup valuable data from 1 and 2. By that time I can expect 5-6 TB drives available on the market.

Big + to stevech for sharing his configuration and others for their input it was all helpful.

Cheers,
Vadimo