Doubts on RAID enclosure setup

[CrisR82]

With the upcoming Black Friday/Cyber Monday, I finally decided to pull the trigger on a big data consolidation I needed to do for a long time and got myself a RAID enclosure, with an upcoming purchase of a couple of HDDs for it, so I thought now is the best time to ask a few questions to make sure I'm doing this correctly.

 

The enclosure I got: QNAP-TR002 (https://www.qnap.com/en/product/tr-002)

The HDDs I will be buying soon: WD UltraStar HC580 24TB (https://www.westerndigital.com/products/internal-drives/data-center-drives/ultrastar-dc-hc580-hdd?sku=0F62796)

 

What I would like to do is have them in a RAID-1 mode, but I have 3 questions that I'm not sure about:

1. Should I use "hardware RAID" with the dip-switches on the back of the enclosure, or use "software RAID" with the QNAP app for Windows?
2. When using RAID-1 (or any RAID if the type doesn't matter), is it possible to transfer the drives to another RAID enclosure (or directly in a PC) and still have them work without formatting them/loosing the data?
3. If a RAID-1 drive dies, is it possible to keep using the other drive as stand-alone without rebuilding the RAID with a new drive? (for example, I have only a few high-risk things I need to make sure are not lost, can I copy just those few files to my PC and then at a later time get a new drive and rebuild the RAID)

Any other info that I should probably know would also be welcome, I have pretty much no experience with these things.

[Jarsky]

7 hours ago, CrisR82 said:

1. Should I use "hardware RAID" with the dip-switches on the back of the enclosure, or use "software RAID" with the QNAP app for Windows?

On a mirror there's not really one that's going to have any big advantages over the other in this scenario. I would probably use the Software RAID (QTS Raid) since your CPU cycles don't really matter in this application; but for a basic 2 disk mirror it doesn't really matter. 
 

7 hours ago, CrisR82 said:

1. When using RAID-1 (or any RAID if the type doesn't matter), is it possible to transfer the drives to another RAID enclosure (or directly in a PC) and still have them work without formatting them/loosing the data?

Being able to transfer drives depends on what type of RAID you're using and what RAID level (when talking about breaking them up). 
- Hardware Raid (including FakeRAID like IST) rely on the specific RAID chipset (or family of chipsets) on that card. 

- Software Raid is limited to its own raid type e.g SHR, QTS, ZFS, MDADM, Windows RAID, Storage Spaces, etc...
 

7 hours ago, CrisR82 said:

1. If a RAID-1 drive dies, is it possible to keep using the other drive as stand-alone without rebuilding the RAID with a new drive? (for example, I have only a few high-risk things I need to make sure are not lost, can I copy just those few files to my PC and then at a later time get a new drive and rebuild the RAID)

For a RAID-1 which is a complete disk mirror; this is fine. You can move the drive and mount it as a standalone drive. 

[CrisR82]

51 minutes ago, Jarsky said:

On a mirror there's not really one that's going to have any big advantages over the other in this scenario. I would probably use the Software RAID (QTS Raid) since your CPU cycles don't really matter in this application; but for a basic 2 disk mirror it doesn't really matter. 
 

Being able to transfer drives depends on what type of RAID you're using and what RAID level (when talking about breaking them up). 
- Hardware Raid (including FakeRAID like IST) rely on the specific RAID chipset (or family of chipsets) on that card. 

- Software Raid is limited to its own raid type e.g SHR, QTS, ZFS, MDADM, Windows RAID, Storage Spaces, etc...
 

For a RAID-1 which is a complete disk mirror; this is fine. You can move the drive and mount it as a standalone drive. 

Thanks for the info, the last part about being able to move the drive as a stand-alone in particular is really awesome to hear ^-^

[Blue4130]

13 hours ago, CrisR82 said:

1. If a RAID-1 drive dies, is it possible to keep using the other drive as stand-alone without rebuilding the RAID with a new drive? (for example, I have only a few high-risk things I need to make sure are not lost, can I copy just those few files to my PC and then at a later time get a new drive and rebuild the RAID)

 

If you don't plan on rebuilding the array, why not just use the two drives as stand alone disks? Use one as normal and the second as a daily/weekly backup, that is powered down and removed when not in use. Much safer than RAID since it is an actual back up, which raid isn't.

[CrisR82]

9 minutes ago, Blue4130 said:

If you don't plan on rebuilding the array, why not just use the two drives as stand alone disks? Use one as normal and the second as a daily/weekly backup, that is powered down and removed when not in use. Much safer than RAID since it is an actual back up, which raid isn't.

Nah, that's not what I meant. I currently have (not kidding) 14 external HDDs, I will be emptying them all onto a 24TB one, with a mirror on another 24TB one through the RAID-1. My question was, because 24TB drives are stupidly expensive, in case one fails, I can really quickly copy the most headache-inducing things real quick (for peace of mind), then leave it be until I can afford a replacement drive to rebuild the array.

I mean I assume data-center-grade drives should last a really long time (I have 12 year old USB 3.0 HDDs working perfectly fine) and it's not like I plan to move them around, but you never know these days.

 

...I'm also super curious about this type of stuff so just general knowledge was a good motivator to ask ^-^;;

[Blue4130]

51 minutes ago, CrisR82 said:

Nah, that's not what I meant. I currently have (not kidding) 14 external HDDs, I will be emptying them all onto a 24TB one, with a mirror on another 24TB one through the RAID-1. My question was, because 24TB drives are stupidly expensive, in case one fails, I can really quickly copy the most headache-inducing things real quick (for peace of mind), then leave it be until I can afford a replacement drive to rebuild the array.

I mean I assume data-center-grade drives should last a really long time (I have 12 year old USB 3.0 HDDs working perfectly fine) and it's not like I plan to move them around, but you never know these days.

 

...I'm also super curious about this type of stuff so just general knowledge was a good motivator to ask ^-^;;

I get what you mean, but just know that RAID isn't  a backup, it is about uptime. There are many situations where RAID doesn't protect you from data loss. Keeping the data on a second drive that isn't constantly connected to the system is a safer way to go.

[CrisR82]

7 minutes ago, Blue4130 said:

I get what you mean, but just know that RAID isn't  a backup, it is about uptime. There are many situations where RAID doesn't protect you from data loss. Keeping the data on a second drive that isn't constantly connected to the system is a safer way to go.

The type of loss I'm worried about is the drive itself failing, like bad sectors, or just natural death - having 2 brand new drives fail at the same time should be pretty much not possible, so if one fails, I'll have the opportunity to actually do something before things get out of hand.

I'm not using this as a backup, just storage the same way I do with my external drives now, the stuff on it I would prefer not to lose but if I do - it's not critical. Things like my family album or game projects I work on are properly secured (actually a 4-3-2 backup - 4 copies, on 3 types of storage, 2 off-site very far away from me and each-other).