Another question about moving files between shares/disks and split-any

[dnLL]

Hi,

I started my unRAID server with 2x4TB disks and no parity. I then added 2 other 4TB disks, one as parity. I'm using the high-water and split-any settings, which means, from my understanding, that unRAID will try to fill up each disk at 50%, then at 75% and so on, with the split-any feature meaning it will split files across any disk even if they're in the same folder. Is that correct? I assume it is because I have all my movies in the same folder and they're split across multiple disks.

 

Now, I have a share for torrent files (for example Linux distro ISOs) and when the downloads are completed, I move the files to the default isos share to be able to use the ISOs for my new VMs. To move the files, I just use my Windows desktop PC and connect to both shares using Samba and move the files. I realized that unRAID is actually moving the files across different disks when doing that, which takes time and write cycles for almost nothing. So I started wondering if there is any better way to do this and if anything bad can happen from me doing it directly from the samba shares (besides premature use of the disks).

 

Also, I plan on adding 2 SSDs as possible cache disks (haven't decided yet if I want to use the cache feature or not). I will definitely move the VHD files for my VMs from the HDDs to the SSDs (in fact, I would like to just move the default domains share to the cache disks I'm about to install). If I configure the share to use the cache disks "Only", I assume it only works for files I start adding to the share and won't modify the location of existing files in the share, correct? So to move all the files I could move them to a different share and then back to the domains share, correct?

 

Thank you for your help, I've been using unRAID only for a month now and I'm loving it so far.

[itimpi]

Not sure I understand what question you are asking in the second paragraph?

 

if you have shares on the array that you would prefer to end up on the cache drive (when/if you add one) then set the share to say Cache=Prefer.    This will tell unRAID you want existing files moved to the cache and new files to go straight to the cache (assuming there is space and you have one).   A secondary impact of this setting is that if there is not enough space on the cache (or you do not have a cache drive) then files get written to the array anyway.   With Cache=Only new files fail if there is not enough space on the cache drive or if you do not have a cache drive.

[dnLL]

10 minutes ago, itimpi said:

Not sure I understand what question you are asking in the second paragraph?

 

if you have shares on the array that you would prefer to end up on the cache drive (when/if you add one) then set the share to say Cache=Prefer.    This will tell unRAID you want existing files moved to the cache and new files to go straight to the cache (assuming there is space and you have one).   A secondary impact of this setting is that if there is not enough space on the cache (or you do not have a cache drive) then files get written to the array anyway.   With Cache=Only new files fail if there is not enough space on the cache drive or if you do not have a cache drive.

My most important question is probably the understanding of how split-any works (1st paragraph) but my question in the 2nd paragraph is just so know if there could be any issue by moving files between shares just using the shares SMB or if letting unRAID managing all of that was fine.

 

Also I have an additionnal question about high-water, since unRAID is moving files from Disk 1 (that was previously filled up at 75%) to Disk 3 (that I just added to the array), Disk 1 is slowly going to go under 50%. Is there a moment where unRAID will decide to go back writing to Disk 1?

 

I didn't know about the Cache=Prefer option, good to know. Also, are you use it will impact files that were written before I set that option up? Because I've played with some of the settings before and it always only had an impact on new files being written rather than files already there.

[itimpi]

3 hours ago, dnLL said:

My most important question is probably the understanding of how split-any works (1st paragraph) but my question in the 2nd paragraph is just so know if there could be any issue by moving files between shares just using the shares SMB or if letting unRAID managing all of that was fine.

 

Also I have an additionnal question about high-water, since unRAID is moving files from Disk 1 (that was previously filled up at 75%) to Disk 3 (that I just added to the array), Disk 1 is slowly going to go under 50%. Is there a moment where unRAID will decide to go back writing to Disk 1?

 

I didn't know about the Cache=Prefer option, good to know. Also, are you use it will impact files that were written before I set that option up? Because I've played with some of the settings before and it always only had an impact on new files being written rather than files already there.

Yes - with Split any set then files in the same folder can end up on different disks.   This is less likely to be an issue if using High Water allocation as that means files written at the same time tend to end up on the same disk.    Moving files between a SMB Shares is always safe.    There are faster ways to move files if you do it locally on the server itself, but that is easier to mess up.

 

UnRAID never moves existing files between array disks on its own.   Therefore adding a new drive does not cause unRAID to start moving files from other disks to the new one.   If you want to move files around then the unBALANCE plugin can help with automating this.   The new drive will be factored into the allocation method for choosing where new files should go so it is highly probable that the new drive will be the candidate for new files.

 

Regarding the cache settings turning on the help in the GUI can help clarify the settings.    The point to remember is that once you have a cache disk this setting does not just control where new files are written, it also controls what action mover should take for moving files between the cache and array disks.

[dnLL]

Thank you for the clarification, this is all very reassuring. I'll buy 2 1TB SSDs this weekend and we will see how that goes later this week. As for moving files, I guess I'll keep doing it the way I'm doing it with SMB and let unRAID decides what's best, even though sometimes I feel like it's taxing disks almost for nothing. It's not something I do frequently enough to bother that much about effects on long-term reliability. 

 

I'll also try unBALANCE eventually. I was a little bit scared since it has his own separate web UI with a service running and everything but I've seen it mentionned too many times to keep ignoring it.