Questions about UnRAID

[Peter.c]

I am new to building a NAS. As I decided to use UnRAID, I have some questions I want to clear before I jump into UnRAID.
1. Can I change the hardware of the system, like CPU, RAM, motherboard, etc, without losing my data?
2. Will it be okay to just add a hard drive to a RAID 5 if I want to expand the NAS in the future, without wiping the data?
These are the 2 main concerns about UnRAID. Hope someone can help. Thank you!

[8-Bit Ninja]

7 minutes ago, Peter.c said:

I am new to building a NAS. As I decided to use UnRAID, I have some questions I want to clear before I jump into UnRAID.
1. Can I change the hardware of the system, like CPU, RAM, motherboard, etc, without losing my data?
2. Will it be okay to just add a hard drive to a RAID 5 if I want to expand the NAS in the future, without wiping the data?
These are the 2 main concerns about UnRAID. Hope someone can help. Thank you!

Yes you can add hardware without loseing your data 

 

As for adding more drives to a raid, (Note this is with my limited knowledge) i don't believe you can without pulling all the off the raid, plugging the new drive in, and then re building the raid 

[jj9987]

For unRAID, you're not supposed to use any other RAID. unRAID is designed to take in individual disks and organize them on it's own. You can easily just add new disks any time, no need to wipe or rebuild or anything.

[Peter.c]

2 hours ago, 8-Bit Ninja said:

Yes you can add hardware without loseing your data 

 

As for adding more drives to a raid, (Note this is with my limited knowledge) i don't believe you can without pulling all the off the raid, plugging the new drive in, and then re building the raid 

Thank you for your help.

 

[Peter.c]

2 hours ago, jj9987 said:

For unRAID, you're not supposed to use any other RAID. unRAID is designed to take in individual disks and organize them on it's own. You can easily just add new disks any time, no need to wipe or rebuild or anything.

So, is unRAID safer than RAID 5?

[VolkovBrad67]

37 minutes ago, Peter.c said:

So, is unRAID safer than RAID 5?

The #1 advantage of UnRaid vs other NAS solutions is that it doesn't require server-grade hardware, it's easy to swap hardware and more importantly, adding disks to the array is the simplest thing in the world. All you have to do is:

1. stop the array
2. power down the system
3. plug in a new drive
4. boot the server
5. assign the new drive to the array from the available slots

UnRaid will zero-out the drive in the background, you can still use the server normally when it's doing that, so the downtime is very minimal. You can use any type of drive you want, any size (as long as it's smaller or equal in size to the parity disk), any brand.

 

You can choose if you want single parity drive or dual parity drive depending on your needs.

[ChalkChalkson]

4 hours ago, Peter.c said:

2. Will it be okay to just add a hard drive to a RAID 5 if I want to expand the NAS in the future, without wiping the data?

The great thing about unraid is, that it is not a raid 5, so yes, you can add drives whenever the array and parity are complete! (Otherwise you will lose the data of the "missing" drive)

4 hours ago, Peter.c said:

1. Can I change the hardware of the system, like CPU, RAM, motherboard, etc, without losing my data?

Yes, but with the motherboard you might need to do a few things:

1. take a photo/screencap of the array config (meaning which serial numbers stand where)

2. swap the mobos

3. boot up

4. configure the array exactly like before (the serial number is important, not the port designation)

5. follow this procedure

 

But in 90% of cases you will be fine and don't need to do that

[ChalkChalkson]

1 hour ago, Peter.c said:

So, is unRAID safer than RAID 5?

kinda... data loss occurs at the same number of lost drives as RAID5/6, but you don't lose all the data, just the data on the broken drives

[ChalkChalkson]

Also, checkout my unraid guide here on the forum, I typed out some of the commonly asked procedures in great detail there  

If you have any other specific questions on how to do stuff, feel free to ask there, so I see it, and can add it to the guide

[Peter.c]

@ChalkChalkson Thank you for your answer! Your guide is very detail!

[Peter.c]

9 hours ago, Ti133700N said:

UnRaid will zero-out the drive in the background, you can still use the server normally when it's doing that, so the downtime is very minimal. You can use any type of drive you want, any size (as long as it's smaller or equal in size to the parity disk), any brand.

 

You can choose if you want single parity drive or dual parity drive depending on your needs.

So, if I have 2x 4TB HDDs at the beginning, I will have 8TB of space. And in the future, I can add 1x 4TB and I will have 12TB?
And if one of the HDD is dead, can I recover the data on the dead HDD? 

[ChalkChalkson]

1 hour ago, Peter.c said:

So, if I have 2x 4TB HDDs at the beginning, I will have 8TB of spaaace. And in the future, I can add 1x 4TB and I will have 12TB?
And if one of the HDD is dead, can I recover the data on the dead HDD? 

Nope, if you have 2 4TB drives, and want single redundancy (data recovery after 1 drive fails), you will have 4TB of accessible storage, if you later add one more 4Tb drive, you will have 8TB, then 12 ans so on and so forth... You basically need to sacrifice your (largest!) drive to the gods of redundancy.

This is why for small storage servers 2 or 3 TB drives are cheaper, even though a 4 or 6 TB drive has a better $/TB ratio  

[ChalkChalkson]

2 hours ago, Peter.c said:

@ChalkChalkson Thank you for your answer! Your guide is very detail!

^^thanks, and as I said, if you have any questions, feel free to ask!

[Jarsky]

11 hours ago, ChalkChalkson said:

1. take a photo/screencap of the array config (meaning which serial numbers stand where)

 

This is a really good thing to get into with custom builds, no matter what array you run.

In software arrays your array data is held across the drives, while in hardware arrays its in the controller. It doesnt matter if you swap out motherboards, cpu's, even reinstall OS.

But it's always a good thing to know, what order your disks are in, and what the parity config / chunk size, etc...are just in case of catastrophic failure.

 

Also it goes without saying, but make sure you dont keep that info on the array

Mines hardware, so I hold a copy of my LSI config on my PC which is sync'd to my onedrive, incase of catastrophic failure. I've had to rebuild the array before, and was able to recover thanks to knowing the exact configuration.

[ChalkChalkson]

1 minute ago, Jarsky said:

In software arrays your array data is held across the drives, while in hardware arrays its in the controller. It doesnt matter if you swap out motherboards, cpu's, even reinstall OS.

But it's always a good thing to know, what order your disks are in, and what the parity config / chunk size, etc...are just in case of catastrophic failure.

^^Had this fail on me once, with the result of data loss (just 2TB and mostly replaceable so.. doesn't really matter, but ripping movies takes so much time -.-)

But then again I had weirder things happen  

[Peter.c]

2 minutes ago, ChalkChalkson said:

^^Had this fail on me once, with the result of data loss (just 2TB and mostly replaceable so.. doesn't really matter, but ripping movies takes so much time -.-)

But then again I had weirder things happen  

Because I am a freelance video editor, I have to store a lot of video files in the NAS. (I will also have a offline backup) 
I need to know if one drive fails, could recover all the data, or just most of it?

 

[ChalkChalkson]

Just now, Peter.c said:

Because I am a freelance video editor, I have to store a lot of video files in the NAS. (I will also have a offline backup) 
I need to know if one drive fails, could recover all the data, or just most of it?

 

All of it.

The issue I had was a catastrophic failure, where the motherboard died and took one of the drives with it, while also messing up the metadata... That is pretty much a one in a lifetime event

[Jarsky]

10 minutes ago, Peter.c said:

Because I am a freelance video editor, I have to store a lot of video files in the NAS. (I will also have a offline backup) 
I need to know if one drive fails, could recover all the data, or just most of it?

 

 

You can rebuild all of the data from parity - my issue was that a drive completely failed, and another had faulty sectors causing it to drop from the array during the rebuild process. In a RAID5, that was too much. A good reason why a RAID6 (2 disk parity) is strongly recommended for larger or more valuable shares.

[ChalkChalkson]

2 minutes ago, Jarsky said:

A good reason why a RAID6 (2 disk parity) is strongly recommended for larger or more valuable shares.

Those type of things happen VERY rarely, and if you keep a backup RAID 5 should be fine.

On the other hand, if you make your living using this NAS as a tool, another drive might not be that high of a price to pay, considering, that rebuilding from backup can effectively take a full day of work from you. Now you have to calculate, if a days work, once or twice in your lifetime, is worth another drive. That should be pretty straight forward, if you know your hourly rate, and are booked to full capacity  

[Peter.c]

@ChalkChalkson @Jarsky Thank you! I think I am going to have 3x 3TB HDDs for now. And maybe adding 1x 128GB SSD as cache drive. 

[Peter.c]

@ChalkChalkson One more question, do I need to have ECC memory for unRAID?

[ChalkChalkson]

Just now, Peter.c said:

@ChalkChalkson One more question, do I need to have ECC memory for unRAID?

no, it is absolutely not worth it at your scale

[Peter.c]

9 minutes ago, ChalkChalkson said:

no, it is absolutely not worth it at your scale

How much RAM do I need if I want to use 6x 3TB HDDs in the future?

[ChalkChalkson]

Just now, Peter.c said:

How much RAM do I need if I want to use 6x 3TB HDDs in the future?

There is a rule of thumb that states 1GB RAM per 1TB of storage, but I don't know how much you should value that...

But look at it this way: single 8/16GB sticks don't cost much more than 16/8GB kits, so I'd probably go for either 1 16 or 1 8GB stick and expend when needed. Which of the two options you should pick should depend on the budged, if you buy dual 8core Xeons then go 16GB, but if you buy a pentium G 8GB should pretty much be it

[Peter.c]

1 minute ago, ChalkChalkson said:

if you buy dual 8core Xeons then go 16GB, but if you buy a pentium G 8GB should pretty much be it

I will use AMD Athlon II X4 640 from my old computer, so I think 8GB it is. Thanks