Hi. I've had mixed responses in the past about shortening the life of HDDs if their spun-down and up too frequently. Being that their a mechanical device, I would assume if the disks spun-down and up too frequently (Ie: 15 times day when something was called from them and unraid would have to power them on), this effect would most certainly reduce their life expectancy. Is this fair to state that this is correct?

I have all Seagate HDDs in my server and I use to have my drives stay on for at lease 30 minutes before they went to sleep. I have recently changed this to 15, but I am now concerned I'm on shortening their lives. I decided to set my drives to spin down after 15 minutes as most of the time that I use my server, I only need to access a specific thing from it, not everything. I have the 's3.sh' script and after all HDDs are asleep it places the server to sleep, meaning all drives that have already fell asleep get woken up to run a "sync" on all disks, then gracefully place the server in sleep mode "everything off".

I have my folders and sub-folders coordinated according to the split level regime, being that if I need to access a specific thing from my server (ie: just music, or just dvds), unraid would only need to keep one drive containing the required contents running and the rest asleep. Obviously if I needed to access something else, like pictures, it would have to power on another drive hence the split level organized method of filing. What do other think about spin-down/up times? Is it a OK to have disks power down/up frequently or is it better to have them spin longer and sleep later? Your thought... Thanks.

Is it a OK to have disks power down/up frequently or is it better to have them spin longer and sleep later? Your thought... Thanks.

 

I set mine to spin down in an hour or two.

Many times I find an hour not enough.

A movie lasts on the average of 90 minutes or so. So the extra time helps in access.

 

I think 15 minutes is too short. Too frequent spinups do shorten life.

I've had drives spin 24x7 for years without issue.  I think some of the fear of drive spinning is F.U.D. (Fear, uncertainty, doubt).

 

The power saved by drives not spinning is only worthwhile if you are not accessing those drives frequently.

A movie lasts on the average of 90 minutes or so. So the extra time helps in access.

 

It could just be my hypoglycemic state, but I'm having trouble understanding your point here on the length of movie vs. spin down time.  If the movie is playing for 90min, wouldn't the periodic reads from the client playing the movie keep the drive spinning?

 

What do other think about spin-down/up times? Is it a OK to have disks power down/up frequently or is it better to have them spin longer and sleep later?

 

I think 60 min is about right.  Drives consume the most power while spinning-up, so from a power savings perspective, you want to minimize the amount of spin-ups.  However, if someone accesses the array once every 61 minutes, perhaps their needs are a bit different.

 

A movie lasts on the average of 90 minutes or so. So the extra time helps in access.

 

It could just be my hypoglycemic state, but I'm having trouble understanding your point here on the length of movie vs. spin down time.  If the movie is playing for 90min, wouldn't the periodic reads from the client playing the movie keep the drive spinning?

 

I find reading compressed files does not always keep the drive spinning.

I notice it sometimes when I go to the next movie or episode.

This is more noticeable when I play a season of compressed tv episodes.

 

Also, Sometimes I pause and do other things. (like check the unRAID forum... heh.)

It's just something I noticed in my usage patterns.

I agree that 15 minutes is too short.  I'm inclined to believe that anything under an hour is too short.  Going over an hour would depend on your usage patterns, as WeeboTech demonstrated.

 

I leave mine at the default setting of 1 hour.  I find this is perfect for my use.  I primarily use my server for watching TV episodes, and most episodes are 30-45 minutes.  Even if the whole episode is buffered into the HTPC's memory (of which I'm dubious, since my HTPC has only 1 GB of RAM), that gives me a minimum of 15 minutes to start the next episode without being exposed to the server's spin up lag.

 

All of my movies are single files (compressed, no video_ts folders) and generally large (2 GB+), so I'm fairly certain my movie disks stay spinning during the entire movie.  I don't watch movies all that often, so this doesn't bother me.

 

If you are concerned with keeping your drives spun down as much as possible, you should check out the cache_dirs script.

Yeah I kind of suspected that 15 minutes was a too short. I've reverted back to 30 minutes a while ago as I stated earlier, when I access the unraid server, I only need one drive spinning as I'm only access it for one kind of data (ie: just movies, or just pictures, etc...), though their is the slight chance that I have to access something else (ie: DVDs then go to a ripped TV show on another drive or open a document), but by the time I've done the latter, whether it be 30 mins or 60 mons, the drives would of all but spun down expect for the drive I was accessing.

So in saying that I guess, and what has been suggested too, it might seem to have the drives running for say 2+ hours. I've got the same vibe from all I speak to about this topic and all state that drive consume more juice when spinning up again, not when they are running constantly, even the unraid calculator proves this fact too:

 

unraid.category5.tv/

 

I might have to reevaluate this and perhaps set the spin down time to > 2 hours for:

 

a). To increase the life line of my drives

b). To save power, keep them on

c). The data drives will be in a ready state practically all the time, and not waiting for drives to become ready again.

 

Thanks for the feedback and suggestions. Food for thought.

what is this 's3.sh' script you speak of?

You can also use this script to avoid the server spun down when your MP och HTPC are online spinup_when_accessed

Read this thread below:

 

http://lime-technology.com/forum/index.php?topic=3657.0

 

It will give you an oversight on the 's3.sh' script. It is pretty good, though I no longer use it as I got my WOL in a power off state sorted.

 

what is this 's3.sh' script you speak of?