Shares and Cache

[jeffreywhunter]

When using a share to a single disk (say disk7) and indicating it uses cache I see the directory created in the cache drive, and almost immediately the files show up on the actual physical disk (i.e. moved from cache to disk7).  I see the files appear on the cache drive under the directory (i.e. "ndh"), then the files are quickly available directly on disk7.  Is that the correct behavior.  I'm happy with that, because the performance of the cache drive is very fast.  I was expecting that the files would remain on the cache drive until the mover moved them next cycle.

[afoard]

You are correct in thinking that the file will move to the disk when the mover runs. 

 

When checking for the files on disk7 are you accessing them directly with the path to the disk? ie /mnt/disk7/ndh

Or are you using the share path of /mnt/user/ndh ?

 

I have a feeling if you try the former you will not actually see the files on disk7 until the mover has run.

[jeffreywhunter]

And then something interesting happens.  I had originally copied about 600gb of data to disk7 from windows 7 (without using the share - the share didn't exist then), then deleted the files (directly from disk7 via windows explorer), then I went to copy files using the share (to test cache) and I was told there wasn't enough space (copying a large number of files).

 

How long does it take for the system to apply a delete?  Is there a way to force a cleanup/delete manually?

[jeffreywhunter]

Great question.  Just to be clear...

 

1. I started a copy of 1.6tb of files to /mnt/disk7 via windows share hunternas-6//disk7 creating a directory structure called /NDHdrive (many files/directories under that).  No share had been created at this point other than what unRAID creates for the disk (hunternas//disk7).

2. The copy went along at a pretty good clip for an hour or so at about 85mb/s, then slowed down over night to about 15mb/s and continuing to slow even more.  Troubling it slowed so much (any ideas on why?)

3. So I cancelled the copy leaving about 600gb files on the disk that had been copied so far.

4. Then I wanted to test to see how the cache (750gb cache) would behave.

5. Created a share (ndh - note lower case) on the drive, set it to use cache.

6. Then I deleted all the files /NDHdrive from the Disk7 share.

7. Then I went to copy the files to the share (ndh) and got an error stating there was not enough space on the disk.

http://my.jetscreenshot.com/12412/20150506-0srm-76kb

I'm assuming this is because the cache drive can't hold all the files I was moving.

 

Here's my dashboard...

http://my.jetscreenshot.com/12412/20150506-9d1f-152kb

 

So am I right in assuming that you can never move more files to a share (not directly to the disk share) using the cache unless the cache is bigger than the number of files you are moving?

 

Would there be a way to have the mover work to move the files as they are being written to the cache?  Or do you have to 'move a chunk', then run the mover manually?

[itimpi]

So am I right in assuming that you can never move more files to a share (not directly to the disk share) using the cache unless the cache is bigger than the number of files you are moving?

This is not an unRAID limit, but a limit in the way that Windows Explorer works and it interacts with the free space reported by unRAID.    In unRAID, once the free space on the cache drive falls below the value you have set for the Min Free Space value (which should be set to be larger than the largest file you intend to copy), the unRAID starts bypassing the cache and writing new files directly to the data drives in the array.

 

You could bypass the Windows Explorer issue by copying files in smaller batches.