Creating Expanding and extending Pool on FreeNAS

[Bytales]

Currently i have a single 10TB hdd in stripe. The plan is to expand and extend the Pool. Here is how i thought i might do it. I just want to know if ist possible.

1)Add another 10TB hdd, and selecting Mirror, now 10Tb+10Tb in mirror, i have still 10TB of space, but with redundancy
2)Add another 10TB hdd, 10Tb+10Tb+10Tb, still mirror, one redundancy, 20TB of space
3)Add another 10TB hdd, 10Tb+10Tb+10Tb+10Tb, still mirror, one redundancy, 30TB of space
4)Taking out one 10TB and replacing it with a 20TB hdd, Array is rebuilded, still 30TB of space, becuase the extra space is lost.
5)Take out and replace all 10TB hdd with 20 TB hdd, one still serves as mirror, but now since all hdd are the same 20TB size, the Array size can be 60TB instead of the original 30TB.

Is this reasoninig correct ? Is this possible. Or in order to extend my Pool without having to backup data, is something that cant really be done ?

Becuase it is easy to back up whole 30 TB to a single hdd, and then create a new pool from 30TB hdd and copy the backup to the new pool.

Or are there any other strategies, for expanding a pool without having the Need to backup the Information that it contains ?

 

[m0nkey_]

If you already have a mirrored vdev and you add a third drive, you then have a mirror+stripe. If the single device fails, you lose your pool.

If you start with a mirror, when you expland you must add another mirror in order to keep redundancy.

 

[Bytales]

So i Need to have a RaidZ volume, in order to add many more drives, which means i Need at least 3 drives to start with.

 

[Mlovelace]

So i Need to have a RaidZ volume, in order to add many more drives, which means i Need at least 3 drives to start with.

Give this a quick read, it will clear up your confusion. https://forums.freenas.org/index.ph...ning-vdev-zpool-zil-and-l2arc-for-noobs.7775/

Cheers!

 

[Bytales]

i tried but the pdfs dont work any more

 

[Chris Moore]

The better plan would be to buy six 4TB drives and configure them in RAIDZ2. That gives you the space and redundancy you need. when you need more space, you can add another six drive vdev or you can change one drive at a time to a larger size until all drives are upgraded and the pool will automatically expand.

 

[Bytales]

I see, so in a RaidZ pool, iyou replace the drives one at a time with larger capacity, once all all replaced the pool expands automatically, this is what i wanted to know.
I dont know about this Redundancy thingy however, i have never had a hard drive making me Problems. It feels like capacity is going to waste. I would stripe them all.

 

[Bytales]

What about if there are different capacities from the getgo ? All extra capacity is lost when combining drives, no ?
However ive read you can crete partitions on the bigger Drivers that are the exact size in bites to the lower drives, and use the extra space as another single Partition.

That is also an Option, if one doesnt want the extra space to go to waste, right ?

 

[Chris Moore]

I would stripe them all.

If you do that you loose two of the key features of ZFS and you might as well not use FreeNAS at all. A stripe provides no protection from data corruption or disk failure. If you have not had either of these happen to you, you have not been using computers long enough or you did not recognize what was happening when it happened.

What about if there are different capacities from the getgo

With regard to what? You need to read about what ZFS is and why it is needed. Once you learn more, you will have your questions answered.

All extra capacity is lost when combining drives, no ?

That doesn't even make sense.

However I've read you can crete partitions on the bigger Drivers that are the exact size in bites to the lower drives, and use the extra space as another single Partition.

This would only be done in a 'worst case' and temporary situation. It is not possible through the FreeNAS user interface and would need to be done at the command line.

That is also an Option, if one doesnt want the extra space to go to waste, right ?

Not a good option.

Please review these resources:

What is ZFS? Why are People Crazy About it?
https://itsfoss.com/what-is-zfs/

10 Reasons Why ZFS Rocks
https://www.enterprisestorageforum....icle.php/3849556/10-Reasons-Why-ZFS-Rocks.htm

Slideshow explaining VDev, zpool, ZIL and L2ARC and other newbie mistakes!
https://drive.google.com/file/d/0BzHapVfrocfwblFvMVdvQ2ZqTGM/view

Terminology and Abbreviations Primer
https://forums.freenas.org/index.php?threads/terminology-and-abbreviations-primer.28174/

Why not to use RAID-5 or RAIDz1
https://www.zdnet.com/article/why-raid-5-stops-working-in-2009/

Hardware Requirements
http://www.freenas.org/hardware-requirements/

 

[danb35]

That doesn't even make sense.

Sure it does--if you put a 1 TB, a 2 TB, and a 3 TB disk together in RAIDZ, the capacity of that vdev will be based on the 1 TB disk--in that @Bytales is quite correct.

 

[Chris Moore]

Sure it does--if you put a 1 TB, a 2 TB, and a 3 TB disk together in RAIDZ, the capacity of that vdev will be based on the 1 TB disk--in that @Bytales is quite correct.

Sure, and you can manually create 1TB partitions on the 3TB drive and on the 2TB drive and mirror the partitions on the 3TB drive with the partitions on the 1TB and 2TB drive. You can do all sorts of things, that are just bad ideas.

 

[danb35]

Agreed on all counts. Just pointing out that that one small part of his question did actually make sense.