Best drive setup for beginner

[mattpitts74]

Hi There, I've spent a lot of hours reading all about FreeNAS, watched lots of videos and also read the useful presentation and hardware requirements, and been reading the manual. But I'm still struggling to some of the details of this setup I'm a pretty IT literate person, but only have experience of using Synology products, so this is all a bit complicated to me. So I still have a couple of questions I need to get clear in my head before starting.

1. I understand that RAIDZ2 is a safer option for redundancy, what is minimum number of drives I will need for RAIDZ2 is it five?
2. If I build a RAIDZ2 system is it simple to increase the storage within the RAID as and when I need more space?
3. I've also stuggled to find very much about how people backup their FreeNAS, apart from having another FreeNAS, which is not really an option for me, also it seems that external backups are not the done thing either. Is there a preferred online backup solution that works well with FreeNAS?
4. I have a fairly random selection of drives of varying capacities that I could use, again my understanding is that this will work, is that correct, but whats the ideal, ( I only have a case and budget for six drives)
5. Is there anymore very clear simple explaination of how ZFS works that anyone can direct me to?

 

[danb35]

To take your last question first, take a look at https://forums.freenas.org/index.ph...-and-l2arc-for-noobs.7775/page-10#post-169581. It will probably answer many of your questions, but I'll take a crack at giving a brief answer here.

The minimum number of disks for RAIDZ2 is four.

To expand your pool, you can either (1) replace all the disks in your array with larger disks (one at a time, following the instructions in the manual), or (2) add another RAID array to the pool. You can't simply turn a four-disk RAIDZ2 array into a six-disk RAIDZ2 array.

There's a plugin for crashplan, which will let you back up whatever data you choose to the cloud. There is a periodic fee for using the crashplan cloud service, but for only one computer it's fairly inexpensive. That's what I'm using for backup right now, though I've only been using it for a couple of weeks.

You can use mixed-capacity disks together in the same array, but if you do, the array capacity will be limited by the capacity of the smallest disk there. For example, if you had 2 x 500 GB disks, 2 x 1 TB disks, and 2 x 2 TB disks, and combined them into a single RAIDZ2 array, your net capacity would be (6 - 2) x 500 GB, or 2 TB. If you then replaced the two 500 GB disks with 2 TB disks, the smallest disk in the vdev would then be 1 TB, so the new capacity would be (6 - 2) x 1 TB, or 4 TB. If you then replaced the 1 TB disks with 2 TB disks, your pool capacity would increase to 8 TB.

The ideal setup is probably for all disks to be the same capacity, but there are plenty of acceptable scenarios where this isn't the case.

 

[mattpitts74]

@danb35 thanks for your quick response, that's really helpful. so if i ultimately want to use six drives I'd be better off starting with 6 drives all of the same capacity.

I assume the only other option is RAIDZ1, which doesn't seem to be reccommended much here that that small number of drives?

 

[danb35]

There are lots of options--stripes, mirrors, RAIDZ1, Z2, Z3, separate volumes on each disk, etc. Which is best will depend on several factors, including your use case, available disks, and expansion plans. If you have six disks available, I'd probably suggest putting them into a RAIDZ2 configuration. If four, I might go for striped mirrors instead. If you have four and are thinking you might want to expand to six in the future, I'd probably lean more toward the striped mirrors.

RAIDZ1 isn't recommended much any more due to the lack of data security with modern HDD capacities. I've used it, and replaced a few disks at different times without any problems, but I don't think I'd recommend it.

 

[sremick]

My case supported up to 6 drives so after doing a lot of research, I opted to build from day 1 with 6 drives all in a RAIDZ2 volume. It'll save me work later on.