[OpenIndiana-discuss] Good SLOG devices?

[Ivar Janmaat]

So you still need enough throughput on the traditional hardisks to 
handle all the writes from memory if I understand correctly.

Ivar

matthew lagoe schreef:
> To be frank if you get 2 years of use out of a drive, while that's not a 
> huge amount of time, its still quite good. Also in 2 years you will have 
> SSD's that you can replace it with for next to nothing that will be even 
> faster.
>
> In regards to your 2nd question it is my understanding that the SLOG is 
> written to so that the OS can return a "write complete". ZFS only does a 
> write cycle once every 5 seconds, as such if you happened to lose power in 
> that 5 seconds you would lose all that data. the SLOG basically buffers the 
> writes to the SSD so in the event of power loss ect, the data is not lost 
> and is read from and written to the zpool on startup.
>
> My numbers may not be exact above but the general idea is that rather then 
> writing to the slower drives, it buffers the writes to the fast SSD then 
> slowly writes to the zpool, making it so that especially small writes are 
> still fast, as the OS returns a "write complete" before its written to the 
> slow drives, while at the same time ensuring your data integrity with the 
> SLOG.
>
> --