Migrating from Windows Home Server 2011 - some questions

[spudbynight]

I have an HP Microserver that I have been using with Windows Home Server for the last while.

I have recently moved to a Mac environment at home and OSX Lion does not play nice with WHS. As a result I am looking to move.

The HP Microserver is currently setup with 4 HDDs. 3X2TB, 1x1TB and the 160GB OS drive.

I understand that Freenas can be run from a USB memory stick - is that right?

What I want to do is migrate across. At the moment I am using Stablebit Drive Extender with my drives. This has popped everything into a single pool and duplicates everything. I am going to take everything out of the pool which will leave me with data spread across the drives in NTFS format.

How can I migrate that data across to Freenas and also use some form of redundant array?

 

[survive]

Hi spudbynight,

I don't think you are going to like this, but about the only sane thing to do would be to get all your drives so the data on plain old NTFS....no drive extender stuff. First thing you need to do is order some stuff. You need a 4GB USB key (look for something physically small), some disk drives (sized as appropriate) and a SATA drive cradle.

Take those drives out of the Microserver & set them aside. Pop out the motherboard and put a 4GB USB key into the internal USB port, install 8GB of RAM while you are there. Take 4 new drives, install them and configure your pool, set up your shares etc. You can mount the old NTFS drives in the cradle and copy the data over to the filer. The Microserver has an e-sata port...you might want to use that (way faster then USB).

-Will

 

[spudbynight]

The moving of data to NTFS is already underway. It is likely to take a day to do...

I have a USB memory stick - a nice small one that holds 8GB. I also have 5GB on the WHS - would I get away with that?

Regarding your idea of buying 4 new drives that leaves me with 4 drives at the end and nowhere to put them. My total drive array is 7GB (ignoring the 160GB which will go). I only have about 3.5GB of data. Is there anyway I could build an array with 2 drives and copy the media onto that array then adding the now empty drives to the array after copying?

 

[survive]

Hi spudbynight,

5GB is still below spec. Fortunately a second 4GB stick should cost you $25.00....get one, you will be glad you did.

You could make a mirror out of 2 drives, fill that up & then add a second mirror of drives to the pool. Doing it that way is kind of nasty though.....zfs won't migrate the data to the space you added.

-Will

 

[spudbynight]

Cost wasn't a factor - it was just the fact I wanted to do this tomorrow! :)

If I have a two drive ZFS mirror don't I really just have RAID 0?

Is there no way to add drives to a ZFS array?

 

[survive]

Hi spudbynight,

If you make a mirror you wind up with, as the name implies, the data being written (mirrored) to both disks....basically the opposite of RAID 0 (also known as RAID 1).

As to your second question....no, there is no way to add a single drive to an existing vdev (virtual device). I know that's different from what you asked, so let me explain.

FreeNAS does a good job hiding this extra layer from you when you make a zfs array (a pool). While it looks like you take some disks & make an array you actually make a "vdev" and the filesystem goes on top of the vdev. One of the ways of expanding a zfs pool is to add more vdevs to it. Building on your question from post #3 above where you asked about starting with a mirror, you could take a second mirror (and a third, forth fifth.....) and add it to the existing pool (originally composed of the first mirror) to expand it, gaining more performance with every mirror vdev you added.

It is more complicated than that...zfs will let you make all sorts of stupid and\or silly additions to your pool. You could add a single drive vdev to your mirror...that's a perfectly valid, stupid thing to do because you just lost almost all your redundancy since the loss of the single disk will cause the loss of the entire pool.

I think the limitation comes from a couple of things. First, zfs came from Sun who made it to run on their "big iron" servers in environments where you had 10's 100's or even 1000's of disks in a pool, so you didn't add drives one by one....you added them by the shelf or the rack. the other thing is there are particular combinations of disks that perform best with zfs, for example a 3 disk raidz performs better than a 4 disk raidz due to "how the math works".

see this link: http://doc.freenas.org/index.php/Quick_Start_Guide#ZFS_Overview_.28optional.29 <-- Look for this line "Optimal RAID-Zx pool member per vdev rule 2n + p" for handy chart.

I suppose the thinking is that you ought to have set it up properly the first time, and if you add a single disk to it you just muck it all up.

-Will

 

[spudbynight]

Thanks Will

Am I right then that a 5 drive array works as well as a 3 drive array? My HP Microserver can hold a maximum of 5 drives.

Can I mix and match 2TB HDDs from different manufacturers and different specs? ie some 5400 some 7200, different cache sizes etc

I can probably copy all the data on my array onto various drives on my network as well as the 1TB and 160GB drives in my home server at present. Could I make a new 5 drive array by adding 2 new 2TB drives and once that is setup and done copy back onto it the data from various locations?