I have three hard disks that I want to cache with FancyCache - but I have found that I have to set up 3 seperate caches. I have found that sometimes it is not so efficient as there is unused RAM/low hits on one drive but fully used and high hits on another.
Would it be possible to have one large cache that works over different drives in future?
Multiple disks - Unified Cache
Re: Multiple disks - Unified Cache
It would degrade the performance with Unified Cache. So far we don't have plans to implement this feature.
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Axel Mertes
- Level 9
- Posts: 180
- Joined: Thu Feb 03, 2011 3:22 pm
Re: Multiple disks - Unified Cache
Does it really degrade the performance?
Ah, ok, I see - you would need to store the volume or disk info along the block number and the block data, and the cache for all cached volumes must use one same block size preferably.
But that doesn't sound so impracticable for me.
How many disks would one cache?
Even if it would be only 1 byte of additional information per block cached, it would be already 256 disk to be addressable / cacheable, right?
And the algorithm could work for the entire cache in only "one" manner, but that would be still fine for me.
Think of the extra byte as an extension in source block address. The highest bits correspond to identifying the volume / disk then. Pretty straight forward in first place. Potentially extending on the current addressing math, but possibly not a big overhead at all.
I am indeed looking for that "one transparent cache" for every drive I touch. I have 50 machines waiting for THIS.
Clearly the caching algorythm would be easiest applied for all volumes / disk identically then.
I think the idea is very valid and worth thinking about.
Regards,
Axel
Ah, ok, I see - you would need to store the volume or disk info along the block number and the block data, and the cache for all cached volumes must use one same block size preferably.
But that doesn't sound so impracticable for me.
How many disks would one cache?
Even if it would be only 1 byte of additional information per block cached, it would be already 256 disk to be addressable / cacheable, right?
And the algorithm could work for the entire cache in only "one" manner, but that would be still fine for me.
Think of the extra byte as an extension in source block address. The highest bits correspond to identifying the volume / disk then. Pretty straight forward in first place. Potentially extending on the current addressing math, but possibly not a big overhead at all.
I am indeed looking for that "one transparent cache" for every drive I touch. I have 50 machines waiting for THIS.
Clearly the caching algorythm would be easiest applied for all volumes / disk identically then.
I think the idea is very valid and worth thinking about.
Regards,
Axel
Re: Multiple disks - Unified Cache
That would be awesome.. DataCore UpTempo allow you to allocate global (& configurable) cache pool for multiple disks with a separated static write buffer for each one.
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Axel Mertes
- Level 9
- Posts: 180
- Joined: Thu Feb 03, 2011 3:22 pm
Re: Multiple disks - Unified Cache
But when has DataCore UpTempo been updated the last time?
I see no support for x64, no for Win 7, no for 2008 Server R2...
And the price is useless.
Regards,
Axel
I see no support for x64, no for Win 7, no for 2008 Server R2...
And the price is useless.
Regards,
Axel
Re: Multiple disks - Unified Cache
That's right.. and I think it's a (discontinued) product now and as far as I know you can't download it from their website anymore.. but I still would like to say that product is really amazing especially if you have more than one physical disk..