Re: [PATCH 0/4] 3- and 4- copy RAID1

[waxhead <waxhead@dirtcellar.net>]

waxhead wrote:
> David Sterba wrote:
>> An interesting question is the naming of the extended profiles. I picked
>> something that can be easily understood but it's not a final proposal.
>> Years ago, Hugo proposed a naming scheme that described the
>> non-standard raid varieties of the btrfs flavor:
>>
>> https://marc.info/?l=linux-btrfs&m=136286324417767
>>
>> Switching to this naming would be a good addition to the extended raid.
>>
> As just a humble BTRFS user I agree and really think it is about time to 
> move far away from the RAID terminology. However adding some more 
> descriptive profile names (or at least some aliases) would be much 
> better for the commoners (such as myself). 
>...snip... > Which would make the above table look like so:
> 
> Old format / My Format / My suggested alias
> SINGLE  / R0.S0.P0 / SINGLE
> DUP     / R1.S1.P0 / DUP (or even MIRRORLOCAL1)
> RAID0   / R0.Sm.P0 / STRIPE
> RAID1   / R1.S0.P0 / MIRROR1
> RAID1c3 / R2.S0.P0 / MIRROR2
> RAID1c4 / R3.S0.P0 / MIRROR3
> RAID10  / R1.Sm.P0 / STRIPE.MIRROR1
> RAID5   / R1.Sm.P1 / STRIPE.PARITY1
> RAID6   / R1.Sm.P2 / STRIPE.PARITY2
> 
> And i think this is much more readable, but others may disagree. And as 
> a side note... from a (hobby) coders perspective this is probably 
> simpler to parse as well. 
>...snap...

...and before someone else points this out that my suggestion has an 
ugly flaw , I got a bit copy / paste happy and messed up the RAID 5 and 
6 like profiles. The below table are corrected and hopefully it make the 
point why using the word 'replicas' is easier to understand than 
'copies' even if I messed it up :)

Old format / My Format / My suggested alias
SINGLE  / R0.S0.P0 / SINGLE
DUP     / R1.S1.P0 / DUP (or even MIRRORLOCAL1)
RAID0   / R0.Sm.P0 / STRIPE
RAID1   / R1.S0.P0 / MIRROR1
RAID1c3 / R2.S0.P0 / MIRROR2
RAID1c4 / R3.S0.P0 / MIRROR3
RAID10  / R1.Sm.P0 / STRIPE.MIRROR1
RAID5   / R0.Sm.P1 / STRIPE.PARITY1
RAID6   / R0.Sm.P2 / STRIPE.PARITY2