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How to use MediaCache on VOD and SSD drives CentOS

Hi,

What would be the proper configuration on mediacache to use the SSD drives and how does it works?

CentOS 6.4

I have mounted 2 SSD 512 on RAID 1 in /cache directory to use the MediaCache feature on WSE, I have about 1.5 TB of media files and I need it to cache only the most visited (I guess that is what it does) but I don’t know how to configure it to work well. I’ve changed the default content directory to my /media folder (where the 1.5 TB data is) and I want to enable the mediacache. Could someone guide me here?

Thanks in advance!

Hello,

I think one element worth noting is WriteRate in regards to optimizing for SSD. Obtain the sustained I/O rate from the drive and take 25-30% of that and set that in the WriteRate parameter under Root/MediaCacheStores/MediaCacheStore.

<!-- SSD drive: assuming 25% of 150MBps sustained I/O rate = 38MBps -->
<WriteRate>38M</WriteRate>

Thanks,

Matt

Regarding the default settings in the Media Cache configuration, these are based on the assumption that the hardware may be shared with other processes on the server. If the partition(s) being used for the Media Cache Store is on dedicated disks then you can safely raise the the default settings closer to the actual rates for the hardware. You should leave a bit of room for overhead so Matt’s suggestion of 25% - 30% below the maximum would be about right.

Roger.

Ok, I’ll try that, but regarding my first question of how implement a good cache system, knowing that I have a /cache/ folder with the SSDs and a /media/ folder with the HDD?

Please see How to scale video on demand streaming with Media Cache for details.

In your case, you would configure the ssd drives to be your Store as it sounds like you may already have done.

For the hdd drive source, you would configure it as a File Source.

With this configuration, your files would be streamed from the store location and only pulled on from the source location when they are not already cached.

Roger.

Hi,

For the Max size, if the partition is dedicated then you can use the full partition size. For Write Rate, this has already been covered by both Matt & myself and it depends on how the partitions and disks are configured.

The max bucket size settings should be fine.

If /cache/ is the partition path then yes, that is right.

Roger.

Hello,

I think one element worth noting is WriteRate in regards to optimizing for SSD. Obtain the sustained I/O rate from the drive and take 25-30% of that and set that in the WriteRate parameter under Root/MediaCacheStores/MediaCacheStore.

<!-- SSD drive: assuming 25% of 150MBps sustained I/O rate = 38MBps -->
<WriteRate>38M</WriteRate>

Thanks,

Matt

Ok, I’ll try that, but regarding my first question of how implement a good cache system, knowing that I have a /cache/ folder with the SSDs and a /media/ folder with the HDD?

Please see How to scale video on demand streaming with Media Cache for details.

In your case, you would configure the ssd drives to be your Store as it sounds like you may already have done.

For the hdd drive source, you would configure it as a File Source.

With this configuration, your files would be streamed from the store location and only pulled on from the source location when they are not already cached.

Roger.

Thanks for your reply Roger,

And what would you suggest for the Maxium size, Write rate, Write rate max bucket size?

The path should be /cache right?