Does RAID 0 Clone or Double Cache Amount?

[TechMasterMind]

I've always wondered if cache would doubke like the rest of the storage or would it lay dormant kind of like VRAM for GPUs

 

Don't say "I would expect"... I can make guesses, I'm asking if anyone *knows*

[WereCatf]

10 minutes ago, TechMasterMind said:

Does RAID 0 Clone or Double Cache Amount?

If we are talking about the storage-device's internal cache, the answer is neither.

[TechMasterMind]

1 minute ago, WereCatf said:

If we are talking about the storage-device's internal cache, the answer is neither.

What other cache would I be talking about And what do you mean by neither? Does it just rely on one drives cache?

[WereCatf]

2 minutes ago, TechMasterMind said:

What other cache would I be talking about

The OS's own cache, for example. Or, if it's a software-RAID, it may also be keeping its own cache. Hardware-RAID-cards also have their own cache.

2 minutes ago, TechMasterMind said:

And what do you mean by neither? Does it just rely on one drives cache?

See above. There are several different caches involved.

[Electronics Wizardy]

The raid card can't access a disk cache directly, thats all up to the drive. The raid card just sends requests to the drive for data, and the disk will use the cache to get some of those requests faster.

[Cyracus]

1 minute ago, TechMasterMind said:

What other cache would I be talking about And what do you mean by neither? Does it just rely on one drives cache?

 There is no intermingling of drive cache in raid, each drives cache is built into the drive to manage data that gets sent to said drive.

[TechMasterMind]

1 minute ago, Cyracus said:

 There is no intermingling of drive cache in raid, each drives cache is built into the drive to manage data that gets sent to said drive.

So does this mean you'll still get a roughly equivilent benefit from the cache as if it were shared?

[TechMasterMind]

3 minutes ago, Electronics Wizardy said:

The raid card can't access a disk cache directly, thats all up to the drive. The raid card just sends requests to the drive for data, and the disk will use the cache to get some of those requests faster.

Does this mean the drives act like they have say 1 GB + 1GB cache instead od a pool like if they somehow combined to make 2GB or would something about raid or such cause issues to make them only 1GB or 0

[WereCatf]

1 minute ago, TechMasterMind said:

So does this mean you'll still get a roughly equivilent benefit from the cache as if it were shared?

How much benefit you get from the drive's internal cache depends on: 1) how much cache there is 2) drive's internal caching-algorithm and how it fits the stripe-size of the RAID.

[Electronics Wizardy]

Just now, TechMasterMind said:

Does this mean the drives act like they have say 1 GB + 1GB cache instead od a pool like if they somehow combined to make 2GB or would something about raid or such cause issues to make them only 1GB or 0

The cache doesn't work like that at all. The raid has no idea if there is cache on the drives at all, and can't control whats on it.

 

But in raid 0 all the drives store different water, so they cache won't hold the same things on different drives.

[Cyracus]

7 minutes ago, TechMasterMind said:

So does this mean you'll still get a roughly equivilent benefit from the cache as if it were shared?

no, the cache cannot be shared. The computer sends it data to be stored (whether raid or not), the data arrives at the drive, the data sent to the drive is stored in drives internal cache, cached data copied to drive.
So the drive's cache only gets involved with data going into or out of the drive regardless of how that data is managed before being sent to the drive