"There is not enough space..." error

[HPLovecraft]

Hi - please can I check something, as I can no longer copy files into a folder in my Drivepool. I have folder duplication enabled, and I think that's part of the issue Here's the setup:

• Until recently, my server's Pool had 4 HDDs in it.
• My videos (TV, films) live in a 'Videos' folder on the Pool.
• Folder duplication on 'Videos' is set to 'x2'. The rules placed 'Videos' content onto (let's call them) HDD 1 (4TB) & HDD2 (3TB).
• HDD2 (3TB) became full, so I added a 1TB partition to the Pool that hadn't previously been used. Let's call that HDD5.
• I changed my balancing rule so that 'Videos' is still duplicated, and now placed on HDD1, HDD2, or HDD5.
• The behaviour I expected was that all videos would end up on the 4TB HDD1, with the duplicated copy on either HDD2 or HDD5. In practice I expected newly added files to be duplicated onto HDD5, as HDD2 is already full.

For a week or two it worked great. New files ended up on HDD1 & HDD5. But tonight when I tried to add a file to the 'Videos' folder, I got an 'There is not enough space...' error message. But there is plenty of space, even allowing for my folder duplication & placement rules: the file could go on HDD1 (loads of room) and HDD5 (loads of room). I know it couldn't be placed on HDD2 (as I know that drive is full).

I assume that the full HDD2 is fouling this up, but don't understand why. There are still two HDDs with space to store this file, duplicated. What am I missing?

[Final edit: the Drivepool 'Videos' folder on the server is mapped onto my PC as a network drive, with its own letter. This setup has been working great for a few years]

Thanks in advance, as always.

[Umfriend]

I am wondering whether you should do a rebalancing becuase with default behaviour, HDD1, 2 and 5 should each have the same amount of free space.

[HPLovecraft]

10 hours ago, Umfriend said:

I am wondering whether you should do a rebalancing becuase with default behaviour, HDD1, 2 and 5 should each have the same amount of free space.

Hi Umfriend, thanks for your reply. Why would the three disks have the same amount of free space under default behaviour? Nothing in the settings makes me expect that.

in fact I'm not sure that'd be a mathematically possible outcome given the differing sizes of the disks: 4TB, 3TB, 1TB. with file duplication requiring my 3TB of Videos are always duplicated on 2 different disks. Doesn't logic suggest the 4TB drive will always have the most free space? Drivepool can't sustain duplication where the 4TB HDD is use twice for the same file?

However, I have made a change that has cured my 'Not enough space...' error message. In the file placement rules for the 'Videos' folder, in the 'Overflow' section, I've checked the box that says "Allow files to be placed on other disks if all the selected disks are this full: 90%". Now my problem appears solved. I've attached a screenshot.

But this troubles me for a couple of reasons:

• It sounds as if my Videos could now end up placed on "other disks" in the pool (potentially HDD3 or HDD4, which I haven't mentioned up to this point). I really don't want that.
• Also "...ALL the selected disks..." are not 90% full - so it seems counter-intuitive that this checkbox should make any difference.
• (...or is it simply that this checkbox is ambiguously labelled)

[If anyone's wondering why I'm being so awkward about insisting which physical drives are allowed to store my duplicated files. the reason is this: I had a bad experience that taught me to spread my duplicates across different brands of disk. I originally had duplication on two Seagates that were bought at the same time, and both of which failed within 48 hours of each other. This was a close call at the time, so now I try to spread my files across different brands, as well as across different physical drives. I appreciate this desire may be causing some of my problem).

 

[HPLovecraft]

UDATE

Well, that was short-lived! Having checked that 'overflow' box Drivepool did indeed start placing my files all over the place, including pooled physical disks where I really don't want my Videos to go (HDD3, HDD4). I've unchecked the box and am trying to sort out the mess.

So any further advice would be welcome. Summary of my problem:

• Approx 3TB of files.
• Duplicated placement allowed on 4TB, 3TB (full), 1TB disks
• Can't add files as there's 'not enough space'

Other options that I've thought of:

• Drill down and specify file placement rules for my subfolders (Kids TV, Kids Films, TV, Home Movies), but that feels like overkill, and will need more hands-on maintenance in the future.
• Buy another 4TB drive to replace the 3TB (can't afford that at the moment).

...but I feel like Drivepool should be able to cope with my Videos without resorting to either of those options?

cheers! Simon

[HPLovecraft]

........AAAAND ANOTHER UPDATE...

Having unchecked the "Allow the files to be placed on other disks..." checkbox and cleared out the files from the 'wrong' disks, the Pool is now working perfectly.

I can now add new files to my 'Videos' folder and they are placed as I hoped, onto the two drives that have space (HDD1 & HDD5). HDD2, still full, seems happy to stay out of it.

But I am utterly baffled why it stopped working, and why it's now started working again. Any interpretation from people brighter than me would be very interesting.

Also @Umfriend: I'd still like to understand why the disks should have the same amount of free space, as per your comment. This is obviously something I'm not getting straight in my head.

cheers, S

[Umfriend]

DP, by default, stores new files on the HDD with most space available. In a caseof x2 duplication and 4, 3 and 1TB HDD it does not work out that well indeed but as soon as you the Pool is larger than twice the largest HDD then it should work like that.

[HPLovecraft]

Thanks Umfriend, I can see how the remaining space should be consistent if my disks were more uniform, and my placement were simpler. I expect I am responsible for some strange behaviour because:

1. My Pool is made of 5 disks of varying sizes: 4TB, 3TB, 2TB, 2TB, 1TB
2. I am using duplication, but also specifying which disk certain files are allowed to go onto.

...so maybe my usage is a bit odd!

I expect if I simply made a Pool, threw all my files in, and allowed Drivepool to make the decisions, I wouldn't be asking questions like this on the forum! :-D