SoftRAID Volume Resizing vs Traditional NAS

[0388279]

Hi All,

I have just set-up my 2018 MacMini/OWC ThunderBay 4/SoftRAID system to act as my file server. I am using RAID 5 volumes. One of the things that I have found that I do not like are the limitations of resizing volumes. For example, let's say you create 3 volumes with the names 1, 2 and 3 and are created in this order. Volumes 1 and 2 can never be greater than maximum size that was declared when creating the volume. Since I do not know how large these volumes are eventually go to be I have to over allocate the size of volumes 1 and 2. This can result in significant inefficiencies in drive space.

What happens with a traditional NAS from say QNAP or Synology? Do the volumes re-size dynamically. Or, if once a volume is size is declared are there limitations on how large the volume can be?

Thank you for your help in advance.

Don Barar

 

[Mikael H]

Hi All,

I have just set-up my 2018 MacMini/OWC ThunderBay 4/SoftRAID system to act as my file server. I am using RAID 5 volumes. One of the things that I have found that I do not like are the limitations of resizing volumes. For example, let's say you create 3 volumes with the names 1, 2 and 3 and are created in this order. Volumes 1 and 2 can never be greater than maximum size that was declared when creating the volume. Since I do not know how large these volumes are eventually go to be I have to over allocate the size of volumes 1 and 2. This can result in significant inefficiencies in drive space.

What happens with a traditional NAS from say QNAP or Synology? Do the volumes re-size dynamically. Or, if once a volume is size is declared are there limitations on how large the volume can be?

Thank you for your help in advance.

Don Barar

To be honest I would just set up a giant storage pool specifically to avoid the administrative overhead. You can set up shares and permissions to divide the data independently of how it’s physically stored on the drives.

Also, on mechanical drives, if the file system allows you to extend a logical volume to an entirely other location on the underlying RAID set - past another volume - you will necessarily create some overhead in seek times for yourself, which may be a bad thing, depending on what you want to achieve.

And finally: if you don’t like how the cabinet manages its disks, and the disks are presented as individual drives, it should be possible to set up a software RAID set directly from macOS, but from a quick web search it looks like you only get to choose between RAID0, RAID1, and JBOD. If you really want a RAID5 you’re out of luck there, in other words.

 

[hobowankenobi]

Synology offers a dynamic resizing if you use their default "hybrid" RAID, which is similar to RAID 5 overall (can lose one drive).

Best part is growing the volume when replacing drives.....with larger drives. Pretty slick. I won't be going back to a traditional RAID controller!

I just swapped out four 4TB HDs for four 8TB HDs (one at a time, letting the RAID rebuild each time), and grew the single boot volume while it was running.

 

[Mikael H]

I won't be going back to a traditional RAID controller!

This. Synology et al hides the gritty details of these operations, but really: At prices most people are prepared to pay, a software driven RAID equivalent on a real server operating system will likely be more feature rich, faster, and - depending on your choices - may be less likely to lose data, than anything a hardware controller can provide. There are more or less user friendly alternatives, with Qnap, Synology and the likes of FreeNAS in one end of the spectrum, and hand-butchering ZFS on top of a Linux distro that doesn’t natively acknowledge it in the other.

 

[0388279]

Hi All,

Thank you for commenting. I decided to follow Mikael's advice of setting up one large storage pool. This works well. And thank you Hobewan for discussing Synology's SHR. I had read about it on Synology's website and suspected that the volume sizes might be dynamic. You comments confirm that the volumes will dynamically resize themselves.

Don