# How are people using ZFS?

## graysky

I made the switch from an mdadm controlled RAID5 to ZFS.  I am curious how others are using ZFS.  I watch Ben Rockwell's talk on ZFS[1,2] and am finding that I am not using most of the advanced features it offers.  It got me wondering how others are using it.

My setup: 3 HDDs in a RAIDZ1 in a dedicated box.  I am not using snapshots, or other advanced features.  I literally have all 3 drives mounted to /mnt/zpool and that's it.

How I use it: I boot up the NAS once or twice a week and run shell script that uses rsync to move over pics, videos, files, etc.

I guess I could create a vdev under my zpool specifically for documents, and enable snapshots for just that part of the zpool.  The majority of my content is user generated images which will not change.

1. http://www.youtube.com/watch?v=3-KesLwobps

2. http://www.youtube.com/watch?v=jDLJJ2-ZTq8

Note - I edited my post which originally asked about RAID5 or RAIDZ1 so consider that when you read frostschutz's post.Last edited by graysky on Fri Oct 18, 2013 3:37 pm; edited 2 times in total

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## frostschutz

You can do whatever you want. As long as you're aware that RAID (regardless which flavour) is not a backup. As long as you do have a backup of your important data.

mdadm RAID 5 is probably easier to achieve with what you already have (a RAID 1 that simply needs to grow) than revamping your setup completely. But if you want to go with ZFS, why not?

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## graysky

 *frostschutz wrote:*   

> ...if you want to go with ZFS, why not?

 

Good point, it seems like a more contemporary solution.

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## graysky

Picked up a 3rd HDD and destroyed the original mdadm array.  Just finished syncing up a new RAIDZ1 and edited my original post.

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## Tender

I use a raidz1 pool with 4x500GB 2.5" SATA HDDs as archive, is part of a always on "low power" AT5NM10T-I-ASUS headless home router, SMART notify enabled on all HDDs, they are spinned down when array is not accessed. 

Compression enabled, dedup disabled.

Some folders are shared in LAN with Samba, other are used for daily incremental backup of the Gentoo root.

The zfs mount point is periodically backed up on an ext4 external USB disk.

ZFS is great for self healing, waiting to see it in action...

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## _______0

 *Tender wrote:*   

> I use a raidz1 pool with 4x500GB 2.5" SATA HDDs as archive, is part of a always on "low power" AT5NM10T-I-ASUS headless home router, SMART notify enabled on all HDDs, they are spinned down when array is not accessed. 
> 
> Compression enabled, dedup disabled.
> 
> Some folders are shared in LAN with Samba, other are used for daily incremental backup of the Gentoo root.
> ...

 

Can it be use to have a subvolume as raw device like LVM, to run VMs? Btrfs lacks this feature saddly.

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## amospalla

 *_______0 wrote:*   

> Can it be use to have a subvolume as raw device like LVM, to run VMs? Btrfs lacks this feature saddly.

 

Yes, it has raw volumes, altough if you want to use these as vm disk backend, there is no reason to put lvm on top of it, zfs is a volume manager also, and can snapshot those raw volumes, for example.

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## _______0

 *amospalla wrote:*   

> Yes, it has raw volumes, altough if you want to use these as vm disk backend, there is no reason to put lvm on top of it, zfs is a volume manager also, and can snapshot those raw volumes, for example.

 

mm... compelling. I know that, plain zfs raw volume, that's what I meant. Btrfs doesn't have that. Current workaround is to use qemu's raw disk inside a subvolume, which isn't very elegant.

How to install zfs? zfs-kmod?

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## amospalla

 *_______0 wrote:*   

> How to install zfs? zfs-kmod?

 

Unmask spl, zfs and zfs-kmod, and emerge zfs.

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