I want to set a block size of 10MB. how would I do this? The max I see is 512KB.
I'm trying to solve a very specific problem by adding PrimoCache to the equation. I have an external USB dock with 18TB hard drive that contains lots of media files. Typical file is maybe 500mb. I can copy this file to internal disk in a few seconds, but if I play the file with VLC, then the hard drive will constantly seek as I watch the video even though the file is contiguous (not fragmented) on the drive.
So as I'm playing a 50 minute 500mb file, every 2-3 seconds, the drive will go "thud" as it seeks. There is nothing wrong with the drive. I think perhaps the dock is poorly designed not to cache large blocks from the drive but I'm not sure.
Anyway, with 512KB blocks, that means it will read a new block every 3 seconds, so with PrimoCache in place, I'm still getting a seek thud every 3 seconds. So instead, I want to cache big 10MB blocks. Then I will only get a seek noise once per minute.
Anyway, I didn't have to explain why I wanted such large blocks, but I assumed I'd just get pushback about inefficiency, etc. unless I explained. i don't care about efficiency, I just want to solve this one problem. Right now, with PrimoCache, I can solve the issue by running md5sum on the file before playing it, since that will force cache it in a few seconds, but I'd like things to work without having to do that annoying extra step.
How to set custom, very large block size?
Re: How to set custom, very large block size?
For PrimoCache to work, you need to pre-cache file. For that, it doesn't matter if block size is 10MB or 4k.
You need to setup some batch file to read© file you want to play to some local SSD drive, and play from there. PrimoCache is not answer for your use case.
You need to setup some batch file to read© file you want to play to some local SSD drive, and play from there. PrimoCache is not answer for your use case.
Re: How to set custom, very large block size?
Yes, as Nick7 said, cache block size doesn't help your problem.
Re: How to set custom, very large block size?
I'm not following at all. PrimoCache is exactly what I need, except the block size is too small. Why would i need to pre-cache the file? Caching is PrimoCache's job. VLC will demand the file blocks off the hard drive, and PrimoCache will load the 10mb blocks on demand into RAM (caching them). Once a block is cached, there will be no disk access until the next block is needed.
As I said, I already tested whether PrimoCache would work by running md5sum on the file, forcing it into PrimoCache's RAM cache. It works as expected, and VLC reads from the RAM cache. So all I need is larger blocks so there is not constant disk activity.
As I said, I already tested whether PrimoCache would work by running md5sum on the file, forcing it into PrimoCache's RAM cache. It works as expected, and VLC reads from the RAM cache. So all I need is larger blocks so there is not constant disk activity.
Re: How to set custom, very large block size?
It has nothing to do with cache block size. PrimoCache doesn't do the read-ahead or pre-fill the whole cache block. It caches data based on access, that is, if VLC or md5sum (in your case) read 1mb data, then PrimoCache will cache 1mb data. Even the block size is 10mb, PrimoCache still caches 1mb data. (This applies to L1 cache, L2 cache is another case.) That's why Nick7 said that you need to pre-cache file which currently is done by md5sum in your case.