Using an SSD for read cache for media library files (jpg and xml)

[Chuck]

I have a bunch of movies across multiple disks, concatenated into a user share. When I browse for movies, there is a delay when a disk has to spin up so the media player can access the jpg and xml file. It seems like I could add a smaller SSD to the array, migrate the xml and jpg files only to the SSD, and eliminate the latency from drive spin up.

 

Will this work as expected, and besides the cost/benefit ratio, are there any downsides?

[Joe L.]

I have a bunch of movies across multiple disks, concatenated into a user share. When I browse for movies, there is a delay when a disk has to spin up so the media player can access the jpg and xml file. It seems like I could add a smaller SSD to the array, migrate the xml and jpg files only to the SSD, and eliminate the latency from drive spin up.

Or, you can install "cache_dirs" and gain the same benefit.

Will this work as expected, and besides the cost/benefit ratio, are there any downsides?

Probably, but at the expense of using up a slot in your array.

[Chuck]

Thanks, I will research cache_dirs. I am already over budget so finding reasons to not spend money is good.

[Spectrum]

If the media player is loading the .jpg for display and querying the .xml for data about the recording then cache dirs probably won't help.  The disks won't have to spin up when the player locates the file, but they would have to spin for the player to access the file.  You might be better off adding all the disks that contain media files to a spinup group so you only get hit with the disk spinup once per session.  Then they will all stay spun up while your watching videos, playing music, etc. and will all spin back down after a timeout when you stop.

 

my $.02

[BRiT]

If you're using XBMC have a read of this topic here: http://lime-technology.com/forum/index.php?topic=7992.0 or http://lime-technology.com/forum/index.php?topic=5874.0 Those threads talk about using a MySQL database for centralized thumbnails and other information. If you use that on an always spinning drive along with cache_dirs, your issues should be solved.

[Blade1001]

Or you could just change your media player to a Netgear NeoTV 550 which enables you to add a USB key to the rear to permanently cache thumbnails of movie and album cover art, and thumbnails of any photos you have on there. More spending I know, but less than the cost of an SSD I'd wager.

[NAS]

XBMC caches thumbs.

 

It wont re-read the file contents twice. Spin up is caused by directory listings which cache_dirs fixes

[kizer]

XBMC Caches just fine and I highly recommend the use of cache_dirs.

 

My library builds are fast and it just works well with what I have.

[Chuck]

Thanks. I am using a WDTV Live hub for playback, and will try the cache_dirs this weekend. It seems like that will solve the issue.

 

I am ok with a lag when the movie starts, but would like the menus to respond quickly.

[Joe L.]

Thanks. I am using a WDTV Live hub for playback, and will try the cache_dirs this weekend. It seems like that will solve the issue.

 

I am ok with a lag when the movie starts, but would like the menus to respond quickly.

We do not know if WDTV caches the jpg images the same way XBMC does.  Please let us know if cache_dirs helps you.

 

Joe L.

[Chuck]

I finally got cache_dirs setup. Simply caching the file/path information isn't speeding up the WDTV. It needs to read the jpg and xml files quickly, and I am not sure how to force those into RAM.

 

So I am going to try a small SSD. I am using a user share so having the movies on a spinning disk and the metadata on the SSD will require some planning but I am sure I can come up with scripts to manage these files in the background.

 

If the SSD doesn't work I will have to break the movies up into folders, but I like having all of them in one directory and being able to use sorting options to find the right media.

[Joe L.]

I finally got cache_dirs setup. Simply caching the file/path information isn't speeding up the WDTV. It needs to read the jpg and xml files quickly, and I am not sure how to force those into RAM.

 

So I am going to try a small SSD. I am using a user share so having the movies on a spinning disk and the metadata on the SSD will require some planning but I am sure I can come up with scripts to manage these files in the background.

 

If the SSD doesn't work I will have to break the movies up into folders, but I like having all of them in one directory and being able to use sorting options to find the right media.

Something like this will force all the .jpg and .xml into the cache memory, but you need to do it in a loop, similar to the cache_dirs.

find /mnt/user/Movies -type f \( -name *.jpg -o -name *.xml \) -exec cat "{}" >/dev/null \;

[Chuck]

I finally got around to putting an SSD in the box to cache these (newegg 20% off lol). It certainly improves media browsing, but there is still an occasional point where the WDTV Live Hub pauses for 8 or 10 seconds. It happens less frequently now, but still happens. The lags waiting for a disk to spin up are gone, which was annoying.