SOLVED best raid with 10 disks

[massmux]

I have 10 sata disks. I would like to be most secure possible, so i was wondering the best raid structure.
The important is security than data space. I would like to have 2 disk failure bonus ( i think good)
which raid do you suggest?

 

[styno]

Depending on how much space you actually need you can go raidz2 / raidz3, maybe with a spare (or two if you really want to go all out)

 

[massmux]

10 disks of 6 TB each. The important is security so i am ok for sacrifying space for safe.
with raidz3, i can loose till 3 disks without loosing data on the array, am i correct?

 

[danb35]

Two disks' redundancy means RAIDZ2.

 

[styno]

That is correct. Make sure you setup a recursive periodic snapshot task as well. Oh and offsite backups, the cloud sync takes care of that.

 

[massmux]

So with raidz2 i can loose 2 disks (doesnt matter which ones) without loosing any data. Right?
Then i can replace and resilver the failed drive

 

[danb35]

So with raidz2 i can loose 2 disks (doesnt matter which ones) without loosing any data. Right?

Correct; with RAIDZ3 you can lose 3.

 

[massmux]

Good. I was afraid because i normally used mirror but i feel raidz2 is safer and more efficient

 

[Arwen]

One note, if you want the highest safety, it helps to have a free disk slot for the replacement disk. ZFS has a somewhat unique feature that allows replacing of failing, (but not yet failed), disks by temporarily mirring them. From the command line, it looks like this;

zpool replace POOL BAD_DISK REPLACEMENT_DISK

When the replacement is complete, the bad disk is removed from the pool.

So, RAID-Z2 can be made safer with this free slot.

Of course, this only works with failing, but not yet failed disks.

 

[massmux]

Thank you Arwen.
This spare disk can be connected physically but not into the array at the beginning, correct? So at beginning i have to create a 9 disk raidz2 array, with the 10th disk as spare?

 

[anmnz]

@Arwen is talking about having a free (empty) disk slot, not an actual spare disk. So that you can connect a new replacement disk without first disconnecting the disk that you are replacing.

RAIDZ3 seems like it would be a better choice than "RAIDZ2 plus a spare disk".

 

[massmux]

thank you all for infos

 

[massmux]

can you confirm that the following is 2 disk fault tolerance?

Code:

		NAME											STATE	 READ WRITE CKSUM												
	   stor										 ONLINE	   0	 0	 0												
		 raidz2-0									  ONLINE	   0	 0	 0												
		   gptid/7acde1785-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		   gptid/7bbc303dd-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		   gptid/7c9e4c2bb-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		   gptid/7d683db94-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		   gptid/7e390658v-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		 raidz2-1									  ONLINE	   0	 0	 0												
		   gptid/7f0c8bb6-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		   gptid/7fdb772e-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		   gptid/f3b1bdb8-2fa6-11e8-a29c-  ONLINE	   0	 0	 0												
		   gptid/818579b4-2dc0-11e8-98f2-  ONLINE	   0	 0	 0												
		   gptid/826efb1c-2dc0-11e8-98f2-  ONLINE	   0	 0	 0

 

[danb35]

can you confirm that the following is 2 disk fault tolerance?

At least two disks, and possibly up to four.

 

[massmux]

you mean that i can lose 2 disks (raidz2), correct?

 

[danb35]

you mean that i can loose 2 disks (raidz2), correct?

I mean that you can lose two disks per vdev. You have two vdevs. Therefore, you can lose up to four disks, if those four disks are two from each vdev. But if three disks fail in the same vdev, you'll lose your pool.