Difference between revisions of "FileSystems"

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== EXT4 ==
 
== EXT4 ==
 
* [[Configuring Ext4 Storage Pool with correct Disk Alignment]]
 
* [[Configuring Ext4 Storage Pool with correct Disk Alignment]]
=== Calculating the Stride and Stripe-width ===
 
* '''''Ext4 Block Size''''' = default 4KiB (not needed to change this value)
 
* '''''Stride''''' = RAID chunk size / Ext4 block size
 
* '''''Stripe-width''''' = Number of physical data disks * Stride
 
==== Examples ====
 
* '''RAID 0''' - 2 Disks - Stripe Size 64 KiB
 
:* Ext4 BS = 4KiB
 
:* Stride = 64 KiB / 4KiB = 16
 
:* Stripe-width = 2 * 16 = 32
 
mkfs.ext4 -b 4096 -E stride=16,stripe-width=32 <dev>
 
# or simply:
 
mkfs.ext4 -E stride=16,stripe-width=32 <dev>
 
 
* '''RAID 1''' - Stripe Size - 128 KiB (AKA Chunk Size)
 
:* Ext4 BS = 4KiB
 
:* Stride = 128 KiB / 4KiB = 32
 
:* Stripe-width = 1 * 32 = 32
 
mkfs.ext4 -b 4096 -E stride=32,stripe-width=32 <dev>
 
# or simply:
 
mkfs.ext4 -E stride=32,stripe-width=32 <dev>
 
 
* '''RAID 5''' - 4 Disks - Stripe Size 512 KiB
 
:* Ext4 BS = 4KiB
 
:* Stride = 512 KiB / 4KiB = 128
 
:* Stripe-width = 3 * 128 = 384
 
mkfs.ext4 -b 4096 -E stride=128,stripe-width=384 <dev>
 
# or simply:
 
mkfs.ext4 -E stride=128,stripe-width=384 <dev>
 
 
* '''RAID 6''' - 10 Disks - Stripe Size 1 MiB = 1024 KiB
 
:* Ext4 BS = 4KiB
 
:* Stride = 1024 KiB / 4KiB = 256
 
:* Stripe-width = 8 * 256 = 2048 
 
mkfs.ext4 -b 4096 -E stride=256,stripe-width=2048 <dev>
 
# or simply:
 
mkfs.ext4 -E stride=256,stripe-width=2048 <dev>
 

Latest revision as of 10:55, 5 August 2015