Drive choice advice

[Sethbest]

Hey. I've been reading up on FreeNAS for a while and finally took the plunge and bought the hardware. I have worked in high level IT for almost a decade now so the hardware basics were easy, found a good deal on a lenovo thinkserver and loaded it up with high quality ECC RAM. I've got a UPS ready for it and already have a high quality router with gigabit everything else.

My goal is reliability, with storage space secondary, and speed a distant third (This will just be for use as a fileshare for my video collections, and my giant directories of application installers). In the past I have just setup RAID1 arrays on a fileserver but always had a lot of issues with bad rebuilds and corruption (cheap RAID controllers probably the main culprit). My interest in FreeNAS is for a high reliability and highly redundant setup.

Anyways I was hoping to use mostly drives I have on hand (The server will only support 5x drives MAX, i know this kind've sucks but should be fine for my needs), except after taking a look I only have 2x 3TB Seagates (ST3000DM001) and 2x 2 TB Western digital blacks. So I could do two RAID 1 sets under ZFS, but I would be much more interested in doing something like buying three more 3TB drives and doing a RAIDZ, or RAIDZ2 setup with one hot spare.

So my questions are:
1. Does the 4x 3TB drives in RAIDZ with one extra as a hot spare make sense? Is there any reason that having only one VDEV like that be ill-advised?
and
2. The two 3TB's i currently have are consumer level 7200 RPM drives. I know ideally I would do something like WD Reds at 5400, but since I already have these two I was thinking of just matching their specs with the next three I purchase. I figure this way I don't lose the benefit of the 7200 RPMs, and the reliability of NAS specific drives would be a negligible improvement considering the redundancy provided by say a RAIDZ2 setup.

I would appreciate feedback
Thanks.

 

[L]

1. I usually like to make my spare do work, I would probably do raidz2 and then you have more space and can lose 2 drives.. If typically only think hot spare if, I have a really big mirrored pool.

2. I personally have almost no opinion on drive types, stay with WD Intel and seagate and you'll do pretty good.. I just ran into this study the other day on wikipedia, http://en.wikipedia.org/wiki/Enterprise_storage (at the fold) .. CMU and google both did reliability testing on commodity vs enterprise drives and found almost no difference. I found that really interesting. To me zfs was designed to take any drive and make it an enterprise drive :)

 

[gpsguy]

With 3+Tb drives, go with RAIDz2. FreeNAS doesn't support hot spares.

 

[Sethbest]

Thanks Linda, and Gpsguy.
The info on the reliability of enterprise drives is really interesting.
I'll probably go RAIDZ2 with the 5 drives. I could even do RAIDZ3 and have enough space for my purposes, but I think two disk failure is less likely than some other freak accident or corruption causing data loss. At that point higher redundancy doesn't really help my odds.

Thanks again, exactly the info I was looking for.

 

[Enchanted14]

Sethbest, Would just like to comment on RaidZ in any configuration. It is not prudent to rely solely on raid redundancy for data protection. Backup of even the most robust Raid configs is always a best practice.

I have no idea how much data you are dealing with but it doesn't sound like a huge amount. You might therefore consider using 1 of your existing drives as a backup disk. Once your NAS system configuration is complete you can backup that configuration to the backup disk. Additionally you can use the r sync feature to create bit for bit backups of any data in your Z pool.

Following this practice will provide you with a very reliable safety net for both your system and your data.

 

[Sethbest]

Thanks Enchanted.
I'm waiting on the drives I ordered so I have not done much with setting up the system yet. I have various 1-2TB drives that I can use for backups but I can't figure out a good way to use them. Ideally I would just plug them into a few external enclosures and plug those in through USB to the server. Does FreeNAS even support something like that though? I know it would read the disks but would it be able to use them as individual volumes without settings them as a zpool? I'm trying to avoid having to set up another PC to run as a backup server to my fileserver.

 

[Enchanted14]

"Ideally I would just plug them into a few external enclosures and plug those in through USB to the server. Does FreeNAS even support something like that though? I know it would read the disks but would it be able to use them as individual volumes without settings them as a zpool?"

Very good questions, unfortunately I am not the one whom can answer them. I am fairly new to FreeNAS myself. It is my understanding that rsync is best at performing incremental backup data over a network to another machine. It seems to me that the utility can be used to perform backup functions from your NAS back to your Windows machine to an attached drive or drives for replication. Here is a link for a fairly good overview of the rsync utility:

https://www.digitalocean.com/commun...to-sync-local-and-remote-directories-on-a-vps

I have not set my NAS up to do this yet even though I intend to do so. I do believe it doable without to much headache.

 

[Enchanted14]

Sethbest,

Did some research on backup and it appears to me that the ZFS filesystem has some very intuitive and useful tools for performing backups. Suggested reading is Section 6 of the version 9.2 documentation covering Storage Configuration specifically Snapshot Tasks and Replication Tasks. These tasks can be set up to automate a backup routine that should fill even the most demanding backup situations.

Happy reading!