Some concerns about a RAID(Motherboard) and unraid

[asmcriminal]

I wanted to build an unraid server. I was planning on running windows on VM on top of unraid. I started to think, "If I have to reinstall unraid I will probably lose all my data?" Of course, I will back up my data but It would take some time to transfer the data. I am projecting a usable 24TBs. Transferring data from the back up would be the last resort.  I didn't want to use a raid card. I was concerned that it might fail and I will lose everything. I recently learned that motherboards support RAIDs... that seems a bit more promising.

 I wanted to run unraid because I want to run a Plex media server. I have been into 4K videos and I need a lot of space. I also want to run Nextcloud and of course Virtual Machines. I am considering a motherboard based array. But that would make unraid pointless.   At this point, I don't know which route I am going to take. I would not use unraid if there is a NAS solution out there for windows. I guess my main questions are that if I take the raid motherboard route, would I lose my data if reinstall windows(Windows would not be part of the RAID. It would be on an SSD). Would I lose my data if I use unraid and reinstall unraid? I think yes, if so is there a way to avoid this?

[Jarsky]

No you don't lose data if you have to reinstall unraid. 

I presume you'll be installing unRAID on a USB key? Once it's all completely configured, best thing to do would be to copy the USB key so you have a backup. 

 

You will only lose your data if:

- You destroy and overwrite your disks

- You have catastrophic hardware failure of your disks

- You encrypt the volume and do not have a backup of the encryption key

 

As for motherboard raid...which is horrible so you really shouldnt use it for complex storage.....but it is seperate to Windows, so no it doesnt matter if you reinstall Windows. 

However motherboard raid (faux raid) has very little recourse for recovery if something does go wrong with the array. 

[asmcriminal]

1 minute ago, Jarsky said:

No you don't lose data if you have to reinstall unraid. 

I presume you'll be installing unRAID on a USB key? Once it's all completely configured, best thing to do would be to copy the USB key so you have a backup. 

 

You will only lose your data if:

- You destroy and overwrite your disks

- You have catastrophic hardware failure of your disks

- You encrypt the volume and do not have a backup of the encryption key

 

As for motherboard raid...which is horrible so you really shouldnt use it for complex storage.....but it is seperate to Windows, so no it doesnt matter if you reinstall Windows. 

However motherboard raid (faux raid) has very little recourse for recovery if something does go wrong with the array. 

I seen a lot of people put unraid on a USB stick. I thought you just used it for installation. I didn't know it ran off USB. That would be good. As you said, I can just back it up. Thanks.

[Jarsky]

2 minutes ago, asmcriminal said:

I seen a lot of people put unraid on a USB stick. I thought you just used it for installation. I didn't know it ran off USB. That would be good. As you said, I can just back it up. Thanks.

 

No they create a bootable USB media for booting the OS. You should probably check out the official Wiki: https://wiki.unraid.net/UnRAID_6/Getting_Started

And perhaps check out their getting started videos which show you how to create the USB, configure your BIOS, and initial setup: https://lime-technology.com/getting-started/

[asmcriminal]

2 minutes ago, Jarsky said:

 

No they create a bootable USB media for booting the OS. You should probably check out the official Wiki: https://wiki.unraid.net/UnRAID_6/Getting_Started

And perhaps check out their getting started videos which show you how to create the USB, configure your BIOS, and initial setup: https://lime-technology.com/getting-started/

Yeah, I have seen a few installation videos. I read the booting section of the wiki...  You said that the USB is just for booting the OS. Where is the OS installed? If it's on a drive... and I reinstall unraid... it would wipe it out.  I guess this is what I am trying to wrap my head around.

[Pyrotechnut]

Unraid stores it's boot files on the usb stick, when you boot the entire is runs from ram. Unraid only writes the changes on boot or when you make a config change. You can install apps and use docker to run specific apps including Plex. You can plug in drives which are not part of your array or pool and copy them manually which will run at sata speeds. There is a channel run by space Invaders e on YouTube with setup guides which is up to date. Be aware that your unraid licence is tied to the usb drive so while you can have a trial for 30 days before buying, get a good quality drive if you decide to move forward.

[Pyrotechnut]

I am currently replacing hardware in

my server due to drive controller failure so If you have any questions I will do my best to help

 

[asmcriminal]

6 minutes ago, Pyrotechnut said:

Unraid stores it's boot files on the usb stick, when you boot the entire is runs from ram. Unraid only writes the changes on boot or when you make a config change. You can install apps and use docker to run specific apps including Plex. You can plug in drives which are not part of your array or pool and copy them manually which will run at sata speeds. There is a channel run by space Invaders e on YouTube with setup guides which is up to date. Be aware that your unraid licence is tied to the usb drive so while you can have a trial for 30 days before buying, get a good quality drive if you decide to move forward.

Okay, I think I understand now. If I install apps, and docker containers, all the apps/programs, and their settings would be installed on the drives in unraid. I vaguely remember people installing dockers and things on the drives.

I never ran a raid before. Thus, I don't have any issues with a controller.

[Pyrotechnut]

Yep. There is a default share for apps and another for VMs. Remember that unraid is looking at the drives directly so using a hardware raid card will cause problems. Unraid is nice because you get to keep more of the overall storage Vs raid as you only choose 1 or 2 drives for parity even in large pools. Sorry about delay, didn't get notified when you replied

[asmcriminal]

6 hours ago, Pyrotechnut said:

Yep. There is a default share for apps and another for VMs. Remember that unraid is looking at the drives directly so using a hardware raid card will cause problems. Unraid is nice because you get to keep more of the overall storage Vs raid as you only choose 1 or 2 drives for parity even in large pools. Sorry about delay, didn't get notified when you replied

Okay thanks. I am new to the forums too. I noticed you have to have the site open in a browser to get alerts. You don't get e-mail notifications. I would suspect you could probably set that up in the settings some place.

 

[Pyrotechnut]

Cheers, am honestly more of a lurker but your questions reminded me of me about 1 year ago. I initially went with freenas and regretted it as I ended up setting things up several times when it didn't meet my needs. Just want to help you avoid the pitfalls I had.

[asmcriminal]

3 hours ago, Pyrotechnut said:

Cheers, am honestly more of a lurker but your questions reminded me of me about 1 year ago. I initially went with freenas and regretted it as I ended up setting things up several times when it didn't meet my needs. Just want to help you avoid the pitfalls I had.

Okay, thanks I appreciate it.

[Jarsky]

15 hours ago, Pyrotechnut said:

Unraid is nice because you get to keep more of the overall storage Vs raid as you only choose 1 or 2 drives for parity even in large pools.

 

Theres not really a difference with hardware RAID, unless you're using mixed capacity drives. 

Hardware RAID you can do a RAID5 (1 disk) or RAID6 (2 disk) parity setup which is the same as UnRAID 1 or 2 disk parity if all disks are the same size

 

Also keep in mind that with the way UnRAID does parity calculation, that if you do use mixed drives then the parity drive has to be at least as large as your largest data drive. UnRAID doesn't stripe data across drives, it has a dedicated parity drive for which it does a simple calculation to rebuild your data drives. The downside to the way UnRAID works is that you only get single disk performance since it doesnt stripe data across the drives, so you really do need SSD caching for more intensive use, unlike with a hardware raid where you get the speed benefit of stripe in a parity setup. Modern disks can easily run a few 4K streams off the single drive though so not really much of a problem in this case, but just one of the caveats you need to be aware of when choosing the setup. 

[asmcriminal]

2 hours ago, Jarsky said:

 

Theres not really a difference with hardware RAID, unless you're using mixed capacity drives. 

Hardware RAID you can do a RAID5 (1 disk) or RAID6 (2 disk) parity setup which is the same as UnRAID 1 or 2 disk parity if all disks are the same size

 

Also keep in mind that with the way UnRAID does parity calculation, that if you do use mixed drives then the parity drive has to be at least as large as your largest data drive. UnRAID doesn't stripe data across drives, it has a dedicated parity drive for which it does a simple calculation to rebuild your data drives. The downside to the way UnRAID works is that you only get single disk performance since it doesnt stripe data across the drives, so you really do need SSD caching for more intensive use, unlike with a hardware raid where you get the speed benefit of stripe in a parity setup. Modern disks can easily run a few 4K streams off the single drive though so not really much of a problem in this case, but just one of the caveats you need to be aware of when choosing the setup. 

In regards to a cache drive... I see some people use a 1TB SSD. Isn't that overkill? I believe something like a 128GB SSD would work just fine.

[Jarsky]

3 hours ago, asmcriminal said:

In regards to a cache drive... I see some people use a 1TB SSD. Isn't that overkill? I believe something like a 128GB SSD would work just fine.

It depends on how much you're writing. UnRAID runs 2 seperate pools, your storage pool and your cache pool. It utilises the cache pool like a Write-Back cache. That is, it writes the whole files to your cache pool (SSD's). Unlike traditional Write-Back RAID though it doesnt write when the complete file has been transferred. UnRAID instead utilises a scheduler like cronjobs that move data from the cache pool to the storage pool. Its typical for this to run once a day during quiet times to minimise impact on the reads, which is why people often use large caches. 

 

Personally I only write about 10-20GB/day on my home server, so I could easily get by with a basic 120GB SSD. Also most people have gigabit network which limits them to 125MB/s anyway which most disks can write at. It's worth pointing out that UnRAID doesnt actually have a read cache which is one of the downsides given you're restricted to single disk speeds.