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spare HDD on RAID5 with nas4free

Posted: 29 May 2014 11:09
by tynolol
Hello everyone,

I'm French so excuse me about my poor english :D

I would like to know if it is possible to add a spare HDD on a RAID5 (I mean a HDD which would be used when one of the others HDD will broke down)

Could explain me how to?

Thks
best regards

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 11:25
by b0ssman
it would be much better to use raid6 or raidz2 than raid5 + spare.

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 11:27
by tynolol
Why ?? I don“t know those two kind of raid..

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 11:30
by b0ssman
2 drive redundancy

see wiki article about raid levels
http://en.wikipedia.org/wiki/RAID

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 11:38
by tynolol
Ok i'll read it thank you.

But my raid 5 is already created (but there is not data yet on it)

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 11:52
by b0ssman

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:16
by tynolol
Ok I read both. Thank you,

I'll delete my raid5 and create a new raid. I have 5 3To HDD, which one of RAID6 or RAIDZ2 do you advice me?

thks

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:23
by b0ssman
that depends.

raidz2 is far superior, but you should have ecc ram for that.

here is an article to read for that.

http://wiki.nas4free.org/doku.php?id=faq:0144

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:26
by raulfg3
tynolol wrote:Ok i'll read it thank you.

But my raid 5 is already created (but there is not data yet on it)

better if you use ZFS ( raidZ) is more robust and forum are full of RAID problems, please consider to use ZFS.

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:31
by tynolol
How to create ZFS on nas4free?? I format my 5 HDD in ZFS pool device, then I go in menu disk-->ZFS-->pool-->virtual device and which type should I choose?

edit : I guess double parity RAIDZ ??

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:42
by b0ssman
yes

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:43
by tynolol
and then? is it created?

edit : what are the dataset, volumes, snapshots and configuration tabs? should I do something in those menus??

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:57
by ChriZathens
You already mentioned that you wanted to have a raid with 5 disks and 1 disk spare..
So you have a total of 6 disks.
b0ssman suggested that you use all 6 disks to create a raidz2 array
So you should format all 6 disks (ZFS pool device) and then, yes, the thing you need in vdev is double parity RAIDZ
Afterwards you will create a pool using this vdev

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 12:58
by b0ssman

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:01
by ChriZathens

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:04
by tynolol
Ok I did all of it ! thanks you 3 of you ! I am asking to myself what are the others menus (dataset, volumes, snapshots and configuration tabs) used to?

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:06
by tynolol
Actually I am surprised because it's very quick to create RAIDZ-2 where as RAID5 take several hours/days while "rebuilding" step

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:13
by ChriZathens
You will need to read a bit about datasets and volumes: head to the wiki: http://wiki.nas4free.org/doku.php
But, IMHO you can ignore datasets and volumes for now (i personally don't use them)
If you are impressed by the speed raidz gets created, you will be more impressed if you need to replace a disk (I hope you won't need to, lol..)
But IF it happens, you will see that rebuilding in ZFS is much faster and much less stressful for your disks

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:18
by tynolol
lol like you said I cross my fingers not to have to, but it will happen sooner or later. Can you explain me how to replace a disk in ZFS?

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:37
by ChriZathens
How do I remove / replace a failed disk in a ZFS array ?

As I said, there is a lot of reading to do...

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:37
by b0ssman
a lot of your questions are answered in the faq

http://wiki.nas4free.org/doku.php?id=documentation:faq

please read that before.

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 13:39
by tynolol
Ok I will read it. Thank you !

Re: spare HDD on RAID5 with nas4free

Posted: 29 May 2014 15:01
by tynolol
How to set a RAID 6 on nas4free? I can't see raid 6 in software RAID menu..

Re: spare HDD on RAID5 with nas4free

Posted: 30 May 2014 08:03
by b0ssman
there isnt a software raid6 under freebsd.
there is raidz2 as it is the better solution.

linux supports raid6 as well as hardware raid controllers.