ZFS Pool | Harddrive Management

[NewbieOnTour]

Hello,

I read a bit about ZFS pools and expanding the size.
I would want to start out with 3x 2TB drives, running in RAID Z (or maybe Raid1+0?). However, is it possible to extend this pool later on? If so, is it correct that I would need to add another 3 drives, with the exact same space, so that I can have ONE ZFS pool?

Cheers,
NoT

 

[Joshua Parker Ruehlig]

This thread has a powerpoint that should explain what you need to know.
http://forums.freenas.org/showthrea...explaining-VDev-zpool-ZIL-and-L2ARC-for-noobs!

You could add ANY vdev to your vdev of 3x2TB drives, to expand your zpool. I would recommend another 3x2TB drives in RAIDZ1, but you could put whatever you want.

 

[NewbieOnTour]

I was actually thinking right now that I don't have much data that needs to have redundancy.
So, is it wise to have 2 drives in RAID 1 for important data and then another pool with just striped drives, therefore I can add drives laters on to that striped pool?

 

[Joshua Parker Ruehlig]

Can't decide for your current situation. As long you know what your'e doing (which you seem to), then your'e probably a better judge then me how to structure your data

 

[paleoN]

Can't decide for your current situation.

Then allow me. ;)

So, is it wise to have 2 drives in RAID 1 for important data and then another pool with just striped drives, therefore I can add drives laters on to that striped pool?

No, it's quite dumb! When, not if, you lose the striped pool it will hurt. It also sounds like you plan on putting 2x or more data on it. The more data you have the greater need for redundancy.

Your first idea was much better, "(or maybe Raid1+0?)". With striped mirrors you would add disks to the pool 2 at a time and it would all be in a single pool.

Fully built how many disks are you planning for? How much did you calculate for your storage requirement?

 

[NewbieOnTour]

No, it's quite dumb! When, not if, you lose the striped pool it will hurt. It also sounds like you plan on putting 2x or more data on it. The more data you have the greater need for redundancy.

You see, that's the point. It won't hurt. See below for explanation.

Fully built how many disks are you planning for? How much did you calculate for your storage requirement?

My plan is to have 4-6x 2TB harddrives. 2 I would run in mirror RAID, here I will put pictures, project files etc on. Data that will hurt, when lost. Then another 2 or maybe 4 2TB drives for other stuff, like movies, series etc... that will not really hurt, when lost.

 

[paleoN]

My plan is to have 4-6x 2TB harddrives. 2 I would run in mirror RAID, here I will put pictures, project files etc on. Data that will hurt, when lost. Then another 2 or maybe 4 2TB drives for other stuff, like movies, series etc... that will not really hurt, when lost.

You are deluded if you think when you lose 8TB of data it won't bother you. It's your NAS & your data and you will do whatever you will.

 

[survive]

Hi NewbieOnTour,

Another way to think about it is if you have made a mirror you have already "burned" your parity disk tax, so if you are starting out with all the drives you might as well take advantage. That said, a raidz of 6x 2TB drives would give me nightmares. Anyway, I would encourage you to think this over now while the drives are empty because it's going to be a pain to change in 6 months when they are full of data.

-Will

 

[NewbieOnTour]

Thanks for all the helpful replies!

That said, a raidz of 6x 2TB drives would give me nightmares.

Why is that? Anything wrong with Raidz?

 

[survive]

Hi NewbieOnTour,

That much data with one parity disk makes me uncomfortable. There's not much that stresses your disk subsystem more than a rebuild and big drives mean long rebuild times. I like the safety of having a second parity drive.

-Will