Help with TrueNas core

[Josh1200]

Hello i am new with TrueNas.

I just want a save truenass server for backupping picture's video's and stuff. I use a pc with this specs:

Intel Core i3 4400 Proecessor
ASRock B85M-DGS
8 gb ram dddr3

3X Seagate HDD NAS 3.5" 2TB ST2000VN004 IronWolf

I installed truenas core but i want to use raid 5 But. i dont see that option. Is RaidZ the same?

 

[Ericloewe]

8 gb ram dddr3

Keep in mind the minimum requirement is 16 GB.

I installed truenas core but i want to use raid 5 But. i dont see that option. Is RaidZ the same?

You might want to read this (shameless plug alert): https://www.truenas.com/community/resources/introduction-to-zfs.111/

 

[Josh1200]

Keep in mind the minimum requirement is 16 GB.

You might want to read this (shameless plug alert): https://www.truenas.com/community/resources/introduction-to-zfs.111/

yeah i know if it works well i will upgrade to 16gb but its a old pc of mine so i will see how it works like this first. But thanks for telling me.

I read teh article. but the part i dont understand is. That i bought 3x 2tb disk because i want to do raid 5 but on true nas that is raidZ2 but i dont see that option i dont understand why

 

[Josh1200]

I only see three options

 

[Josh1200]

• raid5 or raidz distributes parity along with the data and can lose one physical drive before a raid failure. Because parity needs to be calculated raid 5 is slower then raid0, but raid 5 is much safer. RAID 5 requires at least three hard disks in which one(1) full disk of space is used for parity.

Is this correct?

 

[danb35]

i want to do raid 5 but on true nas that is raidZ2

No, it isn't. Try reading the article again.

 

[Ericloewe]

• raid5 or raidz distributes parity along with the data and can lose one physical drive before a raid failure. Because parity needs to be calculated raid 5 is slower then raid0, but raid 5 is much safer. RAID 5 requires at least three hard disks in which one(1) full disk of space is used for parity.

Is this correct?

Broadly, yes, RAIDZ1 is similar in functionality to RAID5.

 

[Josh1200]

Broadly, yes, RAIDZ1 is similar in functionality to RAID5.

Okay. but why cab't i choose RAIDZ1? i have three 2 tb disk so i could do raid 5.

What do i miss here?

 

[Josh1200]

No, it isn't. Try reading the article again.

this is what the article says ", RAIDZ1 is roughly equivalent to RAID5,"

So i dont understand what you mean.

 

[sretalla]

this is what the article says ", RAIDZ1 is roughly equivalent to RAID5,"

So i dont understand what you mean.

You're not reading what he quoted you as saying... you said RAIDZ2 (I guess you didn't mean to do that)

Okay. but why cab't i choose RAIDZ1? i have three 2 tb disk so i could do raid 5.

What do i miss here?

You only have 3 disks, so you can only do RAIDZ1 (from the 3 possibilities of RAID-Z)... so in your case, the menu option lists RAID-Z (which means RAIDZ1)

 

[Josh1200]

Maybe i didn't Said it right. I mean what raid configuration do i need if i want a system that can tolerate 1 disk failure

 

[Josh1200]

You're not reading what he quoted you as saying... you said RAIDZ2 (I guess you didn't mean to do that)

Yeah that was my fault sorry. Thanks for correcting me.

You only have 3 disks, so you can only do RAIDZ1 (from the 3 possibilities of RAID-Z)... so in your case, the menu option lists RAID-Z (which means RAIDZ1)

Ahh okay so RAID-Z For me Means RAIDZ1 = RAID 5 Right? so i have 1 disk fault tolerance?

 

[sretalla]

Yes (although saying the 2 things are equal isn't exactly correct).

1 disk lost in RAIDZ1 gives you a pool that will still function.

 

[Josh1200]

Yes (although saying the 2 things are equal isn't exactly correct).

1 disk lost in RAIDZ1 gives you a pool that will still function.

Okay and if i replace the disk that is broken. Then i the data that was lost is then coming back right?

 

[sretalla]

Okay and if i replace the disk that is broken. Then i the data that was lost is then coming back right?

Again, yes (but not exactly what you said...)

Resilvering is the name for what happens when you perform a replace operation on a missing disk.

The data that needs to go on the new/replacement member of the VDEV is calculated from the parity and data on the remaining good disks.

Checksums (which ZFS writes together with every data block) are also used to verify all of the blocks being read during that process, ensuring all data that is touched is valid.

I don't think it's right to say that any data was lost (but I suppose you can say that some blocks that weren't parity may indeed be gone, so technically "right").

The principle I want to communicate is that the pool continues to operate even with one disk missing, with no "lost data".

If you have some kind of issue with the remaining 2 disks while a third is gone, you may experience data loss or corruption, which is why people who care a lot about their data use RAIDZ2 (where you still have protection even with one lost disk), not RAIDZ1 (where 1 lost disk means no protection is available if corruption is detected).

 

[Josh1200]

Again, yes (but not exactly what you said...)

Resilvering is the name for what happens when you perform a replace operation on a missing disk.

The data that needs to go on the new/replacement member of the VDEV is calculated from the parity and data on the remaining good disks.

Checksums (which ZFS writes together with every data block) are also used to verify all of the blocks being read during that process, ensuring all data that is touched is valid.

I don't think it's right to say that any data was lost (but I suppose you can say that some blocks that weren't parity may indeed be gone, so technically "right").

The principle I want to communicate is that the pool continues to operate even with one disk missing, with no "lost data".

If you have some kind of issue with the remaining 2 disks while a third is gone, you may experience data loss or corruption, which is why people who care a lot about their data use RAIDZ2 (where you still have protection even with one lost disk), not RAIDZ1 (where 1 lost disk means no protection is available if corruption is detected).

Thanks for all the answers. But to resume, If i use RAID_Z1 for me thats (RAID_Z) Then 1 disk can break and my data is not lost but i am not protected anymore, but if i then replace the broken disk i get my data back and i am protected again? If i use RAID-Z2 then if 1 disk broken i am still protected?

 

[sretalla]

Thanks for all the answers. But to resume, If i use RAID_Z1 for me thats (RAID_Z) Then 1 disk can break and my data is not lost but i am not protected anymore, but if i then replace the broken disk i get my data back and i am protected again? If i use RAID-Z2 then if 1 disk broken i am still protected?

That's right.

RAIDZ2 requires 4 disks as a minimum.

 

[Josh1200]

That's right.

RAIDZ2 requires 4 disks as a minimum.

Okay thanks for letting me know and helping me.

Last thing that is still not clear for me is why you say raid 5 isnt the same as RAID-Z1 (RAID-Z in my case?

you said "1 disk lost in RAIDZ1 gives you a pool that will still function."

I am complete new to all of this so thats why i didnt understand it yet, because you probably already told me. But i didnt get it yet. I am sorry for that.

For what i know in Raid 5 there is parity striped on all disk, and that means that if 1 hardisk is broken, that with the parity on the other hardisk when you put in a new hard disk that with the other parity the rebuild the data that was on the broken hardisk.

Do you mean that with RAID-Z1 that works diffrent?

 

[ChrisRJ]

RAID-Z in my case?

There is no such thing as "RAID-Z". Likewise, RAID-Z1 does not exist either.

Please read the resource from @jgreco below. You probably think that I am overdoing it with precision on abbreviations. But in IT precision is a matter of "life or death" (metaphorically speaking, mostly but not exclusively). The number of IT projects that failed because of someone using wrong terminology is obscenely high.

Just one example I was told: A company only had reporting on its sales number with 20 days delay. So the business folks went to the IT guys and said that they wanted real-time reporting. That was about 20 years ago, so a lot of ground work was necessary. After about a year and many millions of dollars spent there was a meeting to check if everything was on track. At this time it became clear that the true requirement of the business was not real-time, but less than 24 hours of delay.

Terminology and Abbreviations Primer

We realize that new users have a lot to learn when they come to FreeNAS. There's a certain amount of confusion added to discussions when users pick random/approximate terms to describe things. I've spent a lot of time quietly trying to translate terms on the reader's side when reading posts...

www.truenas.com

 

[winnielinnie]

You probably think that I am overdoing it with precision on abbreviations.

Can you help me troubleshoot why my 10g is only getting speeds of 1000 mbps for my shares when my iperf speed tests show I'm nearing 9000mpbs????