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linux:fs:zfs:draid [2023/04/25 09:50] – niziaklinux:fs:zfs:draid [2025/08/03 07:39] (current) – niziak
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 ====== dRAID ====== ====== dRAID ======
 +declustered RAID
 +
 +
 +From [[https://pve.proxmox.com/wiki/ZFS_on_Linux#sysadmin_zfs_raid_considerations|ZFS RAID Level Considerations]]
 +<code>
 +
 +In a ZFS dRAID (declustered RAID) the hot spare drive(s) participate in the RAID. Their spare capacity is reserved and used for 
 +rebuilding when one drive fails. This provides, depending on the configuration, faster rebuilding compared to a RAIDZ in 
 +case of drive failure. More information can be found in the official OpenZFS documentation. [1]
 +Note: dRAID is intended for more than 10-15 disks in a dRAID. A RAIDZ setup should be better for a lower amount of disks in most use cases.
 +Note: The GUI requires one more disk than the minimum (i.e. dRAID1 needs 3). It expects that a spare disk is added as well.
 +
 +    dRAID1 or dRAID: requires at least 2 disks, one can fail before data is lost
 +
 +    dRAID2: requires at least 3 disks, two can fail before data is lost
 +
 +    dRAID3: requires at least 4 disks, three can fail before data is lost
 +</code>
 +
 +From [[https://openzfs.github.io/openzfs-docs/Basic%20Concepts/dRAID%20Howto.html|dRAID Introduction]]
  
 <code> <code>
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 </code> </code>
  
-[[https://openzfs.github.io/openzfs-docs/Basic%20Concepts/dRAID%20Howto.html|dRAID Introduction]]+ 
 +<code> 
 +We especially caution storage newbies to be careful with draid—it's a significantly more complex 
 +layout than a pool with traditional vdevs. The fast resilvering is fantastic—but draid takes a hit in 
 +both compression levels and some performance scenarios due to its necessarily fixed-length stripes. 
 +</code> 
 + 
 +<code> 
 +draid2:2d:14c:1s 
 +     |  |  |  | 
 +     |  |  |  L-> one spare 
 +     |  |  | 
 +     |  |  L-> total number of disks to use 
 +     |  | 
 +     |  L-> number of data disks per disk group 
 +     | 
 +     L-> number of parity disks per disk group 
 +</code> 
 + 
 +===== Usage ===== 
 + 
 + 
 Create DRAID with 1 parity and 2 redundancy (on 3 disks): Create DRAID with 1 parity and 2 redundancy (on 3 disks):
  
 <code bash> <code bash>
-zpool create backup draid1:2d <disk1> <disk2> <disk3>+zpool create backup draid1:2d:3c <disk1> <disk2> <disk3> 
 +</code> 
 + 
 +Create DRAID with 1 parity and default redundancy (on 5 disks): 
 + 
 +<code bash> 
 +zpool create backup draid1:5c <disk1>..<disk5>
 </code> </code>