Spin down timers - are they in HDD firmware or stored in slackware


NAS

Recommended Posts

seems this thread has enough valuable info to be moved to the user customization thread, no?

???

 

I think you are probably right. Theres a few things that can be formalised into scripts for distribution and weve talked behind the scenes about kernel customisations.

 

I have tried a few times now to get some solid discussion on kernel tweaks in both #samba and #kernel but no one has known more about it than me. Put in context of how little I actually know about the linux kernel i really disappointed.

 

The next step is a formal post on the Linux kernel mailing list but I am loathed to do this personally. The reason I say this is that we realistically will get one shot at getting the attention of the right people and I feel my understanding will artificially cripple the discussion to me as the lowest common denominator.

 

If acceptable I think either Tom or Joe L should post the question. This way it can be discussed properly and we many get lucky. Joe Im sorry to ask but do you think it is possible for you to do this? Essentially we want to see why cache pressure=0 doesnt do what it proposes to and if there is another way to craft the kernel to match the fairly unique usage pattern of unRAID with low user counts, high disk counts and massive data storage.

 

Help me, Obi-Joe Kenobi! You’re my only hope.

Link to comment
  • Replies 56
  • Created
  • Last Reply

Top Posters In This Topic

  • 1 month later...

Just an update.

 

Continuing to dev/null ls every 10-30 seconds. I also have amalgamated most of my data so as far as possible content of a similar nature is on a single disk. Using 4.4b2 with its performance tweaks (the default ones) and a 45 minute spin down...

 

I can browse my entire unRAID from my htpc without spinning up disks, I can then select a standard 700MB SD movie which spins up one disk and because of read a ahead before the movie is finished its all in RAM and the disk spins down.

 

For me thats really getting there to be a real world improvement on how unRAID works. The only manual part that needs fixed now is recovering from the highwater multi disk data allocations.

Link to comment

This will work on an idle system. The more ram you have the more this situation improves.

If you run a torrent client on your unRAID server, bets are off. Even with 8GB.

Although response does improve a bit.

 

What I would like to know is,  what tweaks you put in.

 

I've been experimenting using mlocate to do the scanning, but that has not proved successful.

 

My next tweak is to alter the dentry cache first by a boot parameter to allocate more hash entries, second to alter the AGE parameter which is used to prune/shrink the cache.

Right now it's hard coded to 45 seconds which cannot be altered via boot parameter.

 

So as it stands your files or directory entries must be referenced in within 45 seconds or they are candidates to be pruned.

 

Link to comment
  • 6 months later...

Just an update.

 

Continuing to dev/null ls every 10-30 seconds. I also have amalgamated most of my data so as far as possible content of a similar nature is on a single disk. Using 4.4b2 with its performance tweaks (the default ones) and a 45 minute spin down...

 

I can browse my entire unRAID from my htpc without spinning up disks, I can then select a standard 700MB SD movie which spins up one disk and because of read a ahead before the movie is finished its all in RAM and the disk spins down.

 

For me thats really getting there to be a real world improvement on how unRAID works. The only manual part that needs fixed now is recovering from the highwater multi disk data allocations.

 

So what is the latest, greatest code/script to prevent un-necessary spin-ups? These discussions are just too technical for a newbie like me...

 

Thanks,

Jaz

 

 

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.