Three, 2.5" drives... Two on USB

[wungun]

What do you all think about using 2.5" drives in a system...?

I think 4 or 5 of these together would be plenty fast enough in my lan and they are whisper quiet and low power draw and run cooler... all important factors

 

[mjws00]

There are lots of 2.5" drives in use. No worries there. Sometimes they can offer pretty great density and $/GB. Speed and spec would be the consideration but if they suit you. Use them.

 

[wungun]

Thanks for the reply...
My current drives weren't bought with a NAS in mind (meaning, all 3 drives are different size... Lol) . I have a smattering of desktop drives, 2 of which are 500gb...and 1more when I pick up a server...
Ill have to study the manual as far as pool/raid configs go, but if I can get away with a 4th half TB drive, that would be sufficient storage for now.
Should I run raid 5 with 4 drives? Or would Z2 be a better option...?

ID rather not mirror, as with the amounts of small-ish drives I have, I dont want to be running like 9 drives 24/7!

 

[jgreco]

Thread evicted from Performance. This is appropriate for the new user forum.

 

[Fraoch]

Should I run raid 5 with 4 drives? Or would Z2 be a better option...?

Please take a look at this first:

https://forums.freenas.org/index.ph...ning-vdev-zpool-zil-and-l2arc-for-noobs.7775/

There is no RAID 5 with ZFS. 4 drives are ideal for RAID Z2 for data protection - the total size will be somewhat smaller than twice that of your smallest drive.

However since your drives are small you may get away with RAID Z1, though you give up a bit of protection (only one redundant drive instead of 2) for more storage.

It's up to you. Double data protection or higher capacity? Be sure to read this before you make your decision:

http://www.zdnet.com/article/why-raid-5-stops-working-in-2009/

keeping in mind that since your drives are smaller the chances of a URE occurring during a rebuild are smaller, though they are not zero.

ID rather not mirror, as with the amounts of small-ish drives I have, I dont want to be running like 9 drives 24/7!

Why not? 2.5" drives run cool and don't consume a lot of power. Starting and stopping them will produce more wear and tear than running them continuously.

If you have a total of 9 drives, you may want a 6-drive RAID Z2 which will give you 2 redundant drives yet will be faster than a 4-drive RAID Z2. Take your two smallest drives, preferably the same size, and mirror them for the OS. Keep the last one as a spare. You could do another combination but keep in mind your vdev will be limited in size due to the smallest drive included, so it may be best to keep the very smallest drives out of the storage vdev.

 

[wungun]

Im not sure how my 2.5" drives match up. None are the same size (750, 1.0 and 2.0) and not sure of the RPM.
I'll probably end up with 3x500gb by the weekend... But they are old (2008, 2009) and noisey. Lol
RaidZ is perfectly fine as I cant see 2 drives dying in a pool before 1 dead one is replaced....
Is it difficult or impossible to add drives in a RaidZ without destroying a pool?
And if I start with the 3x500, and want to migrate later to 3 or 4, 2.5" drives, I image that isn't an issue (assuming that I have enough sata ports )

 

[Fraoch]

RaidZ is perfectly fine as I cant see 2 drives dying in a pool before 1 dead one is replaced...

Make sure you read and understand the link I posted. The danger isn't both drives dying at the same time, the danger is one drive dying in a RAID Z1 and another one suffering a URE while you resilver. It's a distinct possibility with larger drives greater than 1 TB.

Is it difficult or impossible to add drives in a RaidZ without destroying a pool?

Impossible. Please take a look at cyberjock's presentation.

And if I start with the 3x500, and want to migrate later to 3 or 4, 2.5" drives, I image that isn't an issue (assuming that I have enough sata ports )

Either you put the data on a backup and put it back on the new pool or you create a second vdev and move the data over using ZFS replication.

BTW 3 drives would naturally lead to RAID Z1, which puts the data at risk somewhat, especially if the drives are old. It's fine for experimentation, if you're using smaller drives or if the data can be recreated easily.

 

[wungun]

Thanks for all the replies and help! I've been going thru the manual the last few nights.
Can you go from raidz1 with 3 drives them into z2 with moRe drives or an I going to have to replicate and migrate over into a new pool.

 

[Fraoch]

Can you go from raidz1 with 3 drives them into z2 with moRe drives or an I going to have to replicate and migrate over into a new pool.

You will have to recreate from backup or replicate from one vdev to another. Unfortunately you can't add drives or change from RAIDZ1 to RAIDZ2 after the vdev has already been made.

 

[gpsguy]

No you can't switch from RAIDz1 to RAIDz2 without destroying your pool and starting over. Please read cyberjock' guide - it explains this in detail.


Sent from my phone

 

[Robert Trevellyan]

My current drives weren't bought with a NAS in mind (meaning, all 3 drives are different size... Lol) .

Nor were mine! The drives in my system are a mixture of 3x desktop, 1x green and 2x 2.5" laptop drives. It works, and performance is good enough, and with RAIDZ2 on small drives I feel the data is pretty safe. However, I'm working my way towards a 4 x 2TB WD Red RAIDZ2 setup. My plan will then be to double the capacity at some point in the future, by replacing the 2TB drives with 4TB drives one at a time. Then 4TB->8TB, etc.