so i was looking through some stuff on my RAID tools on my computer and it gave me the option to "enable write-back cache" to improve performance. it told me that data may be lost if there was a power failure and what not so i looked up what write-back cache really was. now ive got that part down and i want to enable it, however i couldnt find much out about what happens if there is a power failure, you might lose some data duh..., but does that mean just during the write of a file or group of files or stuff that is queued to be written to the disk? this would be enabled on a mirrored RAID and i actually do have a ups that can keep my computer goin for a good 10-20min during a power failure. any help would be appreciated, thanks!
I think that the write-back cache is volatile memory similar to ram. If you lose power, its gone. I think if you send a bunch of stuff to the hard drive, its putting it all into the cache when you send it, then writes it at its own pace, that way it can receive data at a higher through put and not have to make you wait.. not 100% sure though, but most cache is a temporary storage area.
ya im pretty sure that sounds right. the thing im just wondering is if once the data has been moved to the cache if it writes the data to the disk once the write operation is complete or if it waits for the cache to get full then write data to the disk for multiple write operations. because if the power outage is only dangerous during the write operation itself im fine with that.
