Critical error - What should I do?

[Bidule0hm]

4 stripped drives, all of which are mirrored.

Not exactly; you have 4 striped vdevs and each vdev is a mirror of 2 drives. See the ZFS structure.

I thought it was the best option in terms of reliability, even if you loose half of the capacity

No, it's not. It is for IOPS for example but not for reliability (you lose 2 drives in the same vdev and the pool is gone). The best for reliability is RAID-Z3 (3 drives for parity, 5 for the data), you can lose any 3 drives without losing any data.

But would you say RAIDZ2 is superior to this "RAID 10"ish set-up?

Yes, it is for reliability.

 

[BlazeStar]

wow... ok so I understand now that i didn't understand anything before.

Right now in my office, this is how my main data pool is set up :

http://grab.by/LIIu

Do you think that is a good reliable setup or not?

 

[Bidule0hm]

It is reliable, not the most reliable but it's ok.

But why do you have a L2ARC and a SLOG?

 

[BlazeStar]

Well I use a dataset for virtualization and also NFS shares...

Also I was just aiming to move the writes to something faster, so both my L2ARC and SLOG devices are small SSD drives...

Why do you ask, do you think I should rather just take them out?

 

[Bidule0hm]

Ok, so mirrors are justified then. And L2ARC and SLOG are maybe justified, but wait for an answer of @cyberjock or @jgreco for that ;)

 

[BlazeStar]

Alright thanks!!

But back to my failing drive... how should I proceed to get my home FreeNAS back into shape?

Buy a M1015 card and flash it into IT mode.

Add drives... then what?

Do I need to make an external backup?

Or I can just mirror the drives already there, and then replace the failing drive?

What would be the best procedure (most efficient with the best chances of success)?


Also I want to have 12 TB of space available.

Right now I have 3 X 4TB drives.

How many additional drives do I need to go RAIDZ-2 ?

 

[BlazeStar]

eBay is the place to go for the M1015. If you can instead find an LSI 9211-8i, the flashing process is a little easier.

Found this:
http://www.ebay.ca/itm/New-LSI-Inte...579357?hash=item3aaf441b1d:g:338AAOSwHnFVwxjd
Is that the right device?

 

[Bidule0hm]

Also I want to have 12 TB of space available.

Right now I have 3 X 4TB drives.

How many additional drives do I need to go RAIDZ-2 ?

You need at least 4 drives for a RAID-Z2 but if you want 12 TB usable you'll need 6 drives.

What would be the best procedure (most efficient with the best chances of success)?

Copy the data elsewhere, destroy the current pool, create a new RAID-Z2 pool of 6 drives, copy the data to it ;)

Is that the right device?

Yes.

 

[BlazeStar]

Man... I don't know how to copy the data elsewhere :(

I don't have that much space elsewhere :(

Isn't it possible to create the RAID-Z2 pool in two steps?


Or how do you create a RAID-Z2 pool from the GUI ?


Also, tricky question: how do I know which of my drive is /dev/ada3

I mean, all my HD are physically identical and the cables are not identified... any trick?

 

[Bidule0hm]

Man... I don't know how to copy the data elsewhere :(

I don't have that much space elsewhere :(

In theory it should already be done because you should have at least one backup of this data.

Isn't it possible to create the RAID-Z2 pool in two steps?

No.

But maybe this post will be useful to you (and yes @Ericloewe it's the fourth time now... :P)

Or how do you create a RAID-Z2 pool from the GUI ?

Just follow the manual, it's just a few clicks ;)

Also, tricky question: how do I know which of my drive is /dev/ada3

I mean, all my HD are physically identical and the cables are not identified... any trick?

I made a script to do exactly that, look at the link "Useful Scripts" in my signature :)

 

[Ericloewe]

But maybe this post will be useful to you (and yes @Ericloewe it's the fourth time now... :p)

As long as we don't veer into "build the pool with a fake disk reporting a fake size then destroy the file" territory... Preferably with RAIDZ2 and only one disk missing.

 

[BlazeStar]

In theory it should already be done because you should have at least one backup of this data.

I'm not sure what you mean... I still have the 3 drives which are stripped, and one of which is failing.

No backup of that!

I did a partial backup on an external HD... but only of my important files (like my documents and such).

However, I have several TB of movies and other stuff, which I don't have the space to back up :S

Oh well I'll have to figure something out !

So I'm about to purchase my new hard drives.

Just to make sure :

I have 3 X 4 TB.
I was going to buy an additional 3 X 4TB to mirror them (like a RAID-10 ish setup)
I was hoping that by doing that, and let the 3 first drive mirror on the 3 new drives, I could then replace the failing drive by a new one, and the pool would rebuild itself

But you're saying that will not work, right?
And that I should buy 2 new drives instead, and make a RAID-Z2 pool, which will give me 12 TB of usable space...

And therefore I should buy 2 additional drives, and not 3, and that RAID-Z2 is superior to my RAID 10 thing.

Am I correct?

Also, one last question : let's say I buy 4 new 4TB drives.
And I already have the 3 X 4TB drives, one of which is failing.

I mount a temporary volume of 2 X 4TB = 8TB, it should be enough to backup all my data I think.

Then I take out the failing drive, and trash it.
I still have 4 X 4TB drives (2 old, 2 new), so I create a RAID-Z2 volume, which will give me 8TB of usable space, right?

Then I put my data on that new RAID-Z2... then I can destroy the temporary volume.
Can I add those 2 X 4TB drive to my RAID-Z2 volume then?
In the end it'd be a 6 X 4TB RAID-Z2 volume, giving me 16TB of usable space, correct?

 

[Bidule0hm]

I'm not sure what you mean...

Well, RAID doesn't replace backups, so you should make regular backups of your data.

However, I have several TB of movies and other stuff, which I don't have the space to back up :S

That's the problem...

I have 3 X 4 TB.
I was going to buy an additional 3 X 4TB to mirror them (like a RAID-10 ish setup)
I was hoping that by doing that, and let the 3 first drive mirror on the 3 new drives, I could then replace the failing drive by a new one, and the pool would rebuild itself

But you're saying that will not work, right?

Yep, doesn't work. What you want to do is a similar to RAID01 but ZFS can only do a RAID similar to RAID10, not RAID01.

And that I should buy 2 new drives instead, and make a RAID-Z2 pool, which will give me 12 TB of usable space...

And therefore I should buy 2 additional drives, and not 3, and that RAID-Z2 is superior to my RAID 10 thing.

Am I correct?

If you want a 6 drives RAID-Z2 you'll need 6 drives, then it's just a subtraction... :)

Can I add those 2 X 4TB drive to my RAID-Z2 volume then?

No, you can't expand a vdev, only a pool. See the links "The ZFS Structure" and "Cyberjock's ZFS Guide" in my signature for more details ;)

 

[BlazeStar]

Ok but let's say I have a 5 X 4TB RAID-Z2 pool, giving me 12TB of available space...

When if, in the future, I want to add drives to have more space... how do I do that?

I'm going to have to back up the data off-site, destroy the volume and rebuild it every time?

 

[Bidule0hm]

If you want to add one drive without losing redundancy then yes.

However if you add another RAID-Z2 vdev of 5 drives (so 10 drives total) there's no problem.

You can also replace the current drives one by one by bigger drives.

 

[BlazeStar]

I made a script to do exactly that, look at the link "Useful Scripts" in my signature :)

Well I received my new drives, and my LSI Internal SAS SATA 9211-8i.

I thought the SFF-8087 cables would be included but of course they were not so I had to order that too.

Finally everything came but I left on vacation.

Now I'm back and ready to roll.

I want to identify the failing drive... you said you had a script for that but I can't figure out where it is (and I did visit your "Useful Scripts" post).

My box is open and on the board there are 6 SATA ports identified as SATA1 to SATA6.

Can I rely on this for figuring out?

I don't think so though because SATA2 is empty (nothing's plugged in) but in my disks like I see:

• ada0
• ada1
• ada2
• ada3
• ada4

Anyway I want to know which drive is /dev/ada3

 

[BlazeStar]

Anyone has an idea for my previous post?

Also what's the best way to "replicate" my actual system on the new drives ?

I was going to create the RAID-Z2 vdev of 5 drives, then create my dataset, etc... then I was going to RSYNC the files from the previous drives to the new drives.

Is that a good idea?

What about the jails and stuff... if I just specify a new location in the GUI, are they going to be moved automatically?

 

[gpsguy]

Use Bidule0hm's "Display drives identification infos" script to get the serial number. As you've already discovered there's no correlation between the SATA port numbers and adaX.




Sent from my phone

 

[gpsguy]

Don't touch your failing drive - I scrolled all the back to the beginning of the thread and it looks like you don't have any redundancy.

If you try to replace the drive it will kill your pool.

It looks like you have talked about 2 servers (home and office) and I thought you were trying to replace a drive that's part of a mirror (office server).


Sent from my phone

 

[gpsguy]

How many new drives did you buy?


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