Moving from Windows to FreeNAS - Spanned Volume, different hardrive sizes

[okwei]

I'd like to move to FreeNAS for my home storage server. I have lots of hard drives with different sizes, from 200GB to 2000GB. When using windows, I was able to create dynamic disks and create spanned volumes and expand these volumes when needed. so when FreeNAS, I can do

1. Spanned Volume. Concatenate hard drives and expand the size. And how the ZFS/UFS works when one drive fails. Will I be able to access other drives individually (which I can in windows, I just lose the data on that failed drive). I don't need RAID for this.

2. RAID setup. In Windows, I can create RAID1 volume by using 2 equal sized partitions. My hard drives can be in any size and I'm able to use them to create RAID0/RAID1, can I do this in FreeNAS.

Thanks,
Kevin.

 

[ben]

1. Spanning drives will lead to total volume failure in FreeNAS if any drives die, both in UFS and ZFS I believe. This is highly contraindicated. TL;DR: No.
2. FreeNAS does not like multiple partitions on a drive, and this is definitely not recommended in FreeNAS. TL;DR: No

Alternate suggestions:
1. Single, non-combined drives.
2. Striped RAID1s of each pair of drives with the closest possible sizes - this will lose the amount of space in the larger of each pair that can't be mirrored on the smaller. Note that in any stripe situation in FreeNAS, if any non-redundant data is lost, the entire drive will be lost.

Given that you're using a lot of old drives, I'm gonna guess the server hardware is pretty old too. Please let us know what hardware you have, so we can use that to inform our advice to you. Note that if you have less than 4GB of RAM, no one will recommend any ZFS solution.

 

[okwei]

1. Spanning drives will lead to total volume failure in FreeNAS if any drives die, both in UFS and ZFS I believe. This is highly contraindicated. TL;DR: No.
2. FreeNAS does not like multiple partitions on a drive, and this is definitely not recommended in FreeNAS. TL;DR: No

Alternate suggestions:
1. Single, non-combined drives.
2. Striped RAID1s of each pair of drives with the closest possible sizes - this will lose the amount of space in the larger of each pair that can't be mirrored on the smaller. Note that in any stripe situation in FreeNAS, if any non-redundant data is lost, the entire drive will be lost.

Given that you're using a lot of old drives, I'm gonna guess the server hardware is pretty old too. Please let us know what hardware you have, so we can use that to inform our advice to you. Note that if you have less than 4GB of RAM, no one will recommend any ZFS solution.

Wow, I can't believe FreeNAS does not support any of these. OK, I'll stick with Windows for now.
My hardware is pretty decent - 32GB of memory, 16 hot swap SATA hard drives, I just had too many old SATA hard drives. I guess FreeNAS isn't built for this case.

 

[ben]

Yeah, FreeNAS uses ZFS which is made with consistent drive sizes in mind (it originated in Solaris, which is more enterprise-focused). It's also not well-suited to adding drives after the fact (ZFS does not support adding more drives to RAID groups, only striping more RAID groups together). If you're looking to use old/variable-sized drives, FreeNAS has little to help you. The fallback filesystem, UFS, is better if you have a specific RAID controller you want to use which will be handling all redundancy (which is a suggestion I should have included in my list above). At a software level, though, FreeNAS doesn't focus on your specific use case.

Best of luck!

 

[okwei]

Yeah, FreeNAS uses ZFS which is made with consistent drive sizes in mind (it originated in Solaris, which is more enterprise-focused). It's also not well-suited to adding drives after the fact (ZFS does not support adding more drives to RAID groups, only striping more RAID groups together). If you're looking to use old/variable-sized drives, FreeNAS has little to help you. The fallback filesystem, UFS, is better if you have a specific RAID controller you want to use which will be handling all redundancy (which is a suggestion I should have included in my list above). At a software level, though, FreeNAS doesn't focus on your specific use case.

Best of luck!

If I choose to use UFS, can I combine different hard drives into 1 big volume, or I have no choose but to create 1 volume for each hard drive? and can I extend the volume at a later time, with different sized drives.
I'm go through the documentations, and I found it focuses too much on RAID setup (I couldn't figure out if I can just setup a basic drive without any RAID configuration). I understand FreeNAS is enterprise-focused, but lots of the users here are probably trying to build a home NAS using freeNAS. It's not convenience for regular users to buy like 10 harddrives same size at once. And that's why I end up with so many SATA drives. I bought 4 500GB 3 years ago, did a hardware RAID, and now it makes more sense to buy 1T/2T harddrives, with FreeNAS, I guess, I could build another RAIDz volume, but can't easily extend an exiting volume (because the drives are in different sizes). A few years later, 3T/4T drives will be popular. You get what I'm saying. It seems to me that FreeNAS's soft RAID focus on performance rather than convenience, where Microsoft's SoftRAID/Drive Extender focus on convenience rather than performance - do we have something I can have both?

Thanks,

 

[ben]

No, UFS has even less of what you need than ZFS - it's there for people with limited RAM or who strongly want to use hardware RAID. UFS volumes can't easily be extended, and the same restrictions on mirrors and dissimilar drive sizes as ZFS still apply. Such a solution may exist, but unfortunately (when it comes to variable drive sizes) FreeNAS is not it. Off the top of my head I can't think of a better alternative for you, but my experience is limited to the BSD world and hardware RAID.

 

[paleoN]

It's not convenience for regular users to buy like 10 harddrives same size at once.

I doubt most "regular" users go beyond 6 drives.

And that's why I end up with so many SATA drives. I bought 4 500GB 3 years ago, did a hardware RAID, and now it makes more sense to buy 1T/2T harddrives, with FreeNAS, I guess, I could build another RAIDz volume, but can't easily extend an exiting volume (because the drives are in different sizes). A few years later, 3T/4T drives will be popular.

2. Striped RAID1s of each pair of drives with the closest possible sizes - this will lose the amount of space in the larger of each pair that can't be mirrored on the smaller.

Striped mirrors or multiple mirrored pools gives you the most flexibility. You can replace or extend the drives 2 at a time. You can also have different sized vdevs. It's not recommended as that will lead to unbalanced data placement and performance.​

 

[okwei]

I doubt most "regular" users go beyond 6 drives.

Well, I guess FreeNAS isn't for "regular" user. You may not have 6 drives from day one, but as your requirement for space grows, you will end up with more, and in different sizes..

I went through Windows 8's "Storage Spaces", I found it's way easier to understand and use for regular users. I'm giving up on FreeNAS.

Here's some details:
http://blogs.msdn.com/b/b8/archive/...rage-for-scale-resiliency-and-efficiency.aspx

 

[bollar]

Well, I guess FreeNAS isn't for "regular" user. You may not have 6 drives from day one, but as your requirement for space grows, you will end up with more, and in different sizes..

I went through Windows 8's "Storage Spaces", I found it's way easier to understand and use for regular users. I'm giving up on FreeNAS.

Here's some details:
http://blogs.msdn.com/b/b8/archive/...rage-for-scale-resiliency-and-efficiency.aspx

In this light, ZFS has some similar features, but it's absolutely not a plug-and-play solution today -- it is the best-in-class cross-platform file system at the expense of losing ease of setup features.

Looking at the MSFT article, you'll note in the mirrored drives example, all drives in the same mirror are the same size -- ZFS works the same way. Similarly, in parity arrays, ZFS can use Vdevs of differing size disks in the same zpool, but it's admittedly not the same flexibility MSFT offers.

On MSFT's downside, it's a proprietary system that only works on Windows 8 Server. ZFS is supported on many platforms, so a pack of disks can be moved from FreeBSD to Linux or Windows and it's possible to mount the array. IMO, it's a huge feature that few other systems can match.

 

[cyberjock]

Yeah, I don't see how Microsoft Server will be better for the OP than ZFS. Neither one really will do what the OP wants. Mixing and matching different size drives really just doesn't work very well at all. The law of conservation of data really kicks butt when you want to mix drives.

 

[bollar]

Actually, it turns out that Storage Spaces have similar limitations to other RAID systems. As you'll note here, available space is limited by the smallest drive in the Parity array. Storage Spaces explained: a great feature, when it works

 

[okwei]

Actually, it turns out that Storage Spaces have similar limitations to other RAID systems. As you'll note here, available space is limited by the smallest drive in the Parity array. Storage Spaces explained: a great feature, when it works

Keep in mind MS still support the spanned volume as in previous windows.
And I believe in the parity array, you can divide a bigger drive into smaller partitions to match up with the smallest drive.

 

[bollar]

Keep in mind MS still support the spanned volume as in previous windows.

But spanned volumes don't provide any protection -- they're effectively RAID0, so the loss of any single drive will cause the loss of the entire array. But if this is really what you want, FreeNAS does do this -- it's called "striped" in the ZFS setup.

And I believe in the parity array, you can divide a bigger drive into smaller partitions to match up with the smallest drive.

I'm not familiar enough with it to comment, but that does make me wonder what you do with the other partitions?

 

[okwei]

But spanned volumes don't provide any protection -- they're effectively RAID0, so the loss of any single drive will cause the loss of the entire array. But if this is really what you want, FreeNAS does do this -- it's called "striped" in the ZFS setup.



I'm not familiar enough with it to comment, but that does make me wonder what you do with the other partitions?

No, Spanned volume isn't stripped, if you lose one disk, you only lose data on that disk. each disk can be read individually. when you have an extra drive, just add to this spanned volume. http://www.youtube.com/watch?v=89sRIE1LV_o
And the other partitions, you can create a volume and assign a drive letter to it, or you can mirror/stripe that partition with another partition.

And from what I read, the new windows storage space should be able to do the same. I'm setting up an windows server 2012 in a few days, and I'll let you know.

 

[bollar]

No, Spanned volume isn't stripped, if you lose one disk, you only lose data on that disk. each disk can be read individually. when you have an extra drive, just add to this spanned volume. http://www.youtube.com/watch?v=89sRIE1LV_o

Nice video, but still, this isn't fault tolerant, so this isn't what ZFS is about. If you don't care about losing data and you're a Windows shop, then it sounds like you've found the solution you need -- we can see the ZFS roadmap from Oracle and we know this isn't something you're going to see here or on any other ZFS-based system.

 

[cyberjock]

Yeah, you're an idiot if you choose to use ZFS with a multi-disk RAID0 versus a Windows RAID0 or spanned. Even more so if you are in a Windows shop.

Why you'd want a high reliability file system like ZFS and THEN make the choice to have zero failure protection is completely beyond me. Those choices conflict in the worst possible way.

 

[cyberjock]

I'd never want to use spanning because I'd have no idea which drive had which data. I'd much rather KNOW what data is still around if a disk fails than be guessing 1 out of X when a disk starts acting up. I couldn't even "unplug" the drive and take it somewhere to share with someone because I don't know which drive has which data.