I'm using an IDE Hitachi 250G drive for my Cache. My question is would I benefit from faster spped when data is being moved off the Cache drive to my data drive(s) if I switched to a Sata II drive? It seems to take quite a while to move 30 to 40G off the cache to a data drive.

 

Another problem I have with the cache drive is when it is writing to a data drive I cannot watch videos or listen to music from my unRAID server. It stutturs horribly. Anyone else have this problem?

I'm using an IDE Hitachi 250G drive for my Cache. My question is would I benefit from faster spped when data is being moved off the Cache drive to my data drive(s) if I switched to a Sata II drive?

 

You would benefit, but not that greatly.

 

It seems to take quite a while to move 30 to 40G off the cache to a data drive.

 

Writes to the parity protected data drives are going to be between 10-15Mb/s.

It's going to take a while.

 

Another problem I have with the cache drive is when it is writing to a data drive I cannot watch videos or listen to music from my unRAID server. It stutturs horribly. Anyone else have this problem?

 

I think the trick here is to use rsync with the --bwlimit parameter.

I mentioned this once before. I don't use a cache drive, so I cannot provide the exact solution.

In any case, what I do when moving files between disks is do an

 

rsync --bwlimit=8192 --remove-sent-files -avP $src $dst

 

(you probably don't need the -P or even the -v I use it because I do it within a window.)

 

This has the effect of limiting how much data moves from source to destination at a time.

It keeps the buffer cache from filling up so high that nothing else can be done on the array while it is being flushed.

 

Of course the moves go slower, but it keeps the array running smooth enough that massive directory moves do not affect my reads.

 

I do this so my torrents are not affected, and by golly, it works LOL!!! 

I've been looking at implementing a cache drive, however the thought of streaming from the protected array being dramatically slowed during the cache sync has put me off.

 

rsync with bwlimit seems a viable option, but I'm unable to find reports of anyone using it successfully with an unraid cache drive, or any pointers on how to best configure unraid to use it.

 

Anyone willing to share their experience?

 

Thanks.

 

so a proper schedule is not enough?

you stream all day and all night?

 

 

My concern is that a large amount of writes during the day could cause the nightly cache move to overlap into morning streaming.

 

Perhaps the concern is unwarranted.