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Answering my own question. After having basically given up on the DrivePool remote app on my replacement laptop for the past 4 weeks, I decided again to uninstall the app and reinstall it with a fresh copy a few days ago. For whatever reason, this time the app worked and connected to my DrivePool on my home server. It's all a mystery to me as to why it did not work before, but it's working now.

If you are only transferring that single 1 TB file once in a blue moon, it might be easiest to temporarily turn off the SSD Optimizer until that file transfer is complete. Is it possible to have your backup program split the file into smaller parts for easier transfers? You can also just transfer files directly into a DrivePool HDD and DrivePool should pick it up without any problem. I have done that in a few cases and it worked fine for me. Of course, that circumvents your SSD and probably will be a much slower transfer. But at least you would not have to turn off the SSD Optimizer for all your other file transfers.

I really like DrivePool, but I will admit that bad things have happened to me when my pool reaches its max storage over 95% like you mentioned. Most frequently, I get Duplication Inconsistent errors and I don't know how to fix them - other than adding more storage and/or removing data from the pool. Rebalancing does not help much if your HDDs are already over 95%. As a rule of thumb, IMHO, DrivePool should never be considered a backup solution. So if you lose a pool drive, and lose data on the pool, you should have already had a backup offline stored somewhere else for recovery. In my case, I use DrivePool as a media storage server and if I lose a pool drive, and some or all of that data on the failed drive, I might not even bother to recovery the loss with my backups. Once I watch a movie, for example, I don't really care if it stays on my DrivePool or not. So I would probably not restore a copy from my backup copy. I try to keep as much free space on DrivePool as my largest drive in the pool. That way, if a drive starts showing signs of failure, then DrivePool (via Scanner) has a chance of offloading the failing drive into the pool before it completely dies. I have had some drives report a problem and I was able to offload the drive into the pool over a day or two. That's when things go good. Other times, a failing drive may die within hours, and there is not time to fully transfer all files off the drive. And, of course, I have had some drives just up and die without any warning.... DrivePool offers duplication, but to be honest, I have never really understood the method it duplicates the files. Worse yet, if a file becomes corrupt, DrivePool cannot tell you which is the good copy and which is the corrupted copy. From what I understand, DrivePool at best can only tell you that one copy is older than the other. DrivePool itself cannot repair any corrupt files or tell you which copy is good. Over a period of time, I use DrivePool Duplication less and less. What I do for my media files is use a free program called MultiPar which creates .par2 files for verification and recovery. I have MultiPar set to create 10% recovery files, which is usually enough to repair a track or two on a music album folder. In DrivePool, any album folder, for example, may have music tracks on more than one pool drive. If you lose a HDD, you might lose a track or more on a failing HDD. With the .par2 verification, you can tell within a few moments if your data set is all there, if the data can be recovered from your .par2 recovery files, or if you have to pull out that backup copy from the closet like I mention earlier. Anyway, the verification and recovery features of MultiPar have saved me lots of time and effort after a HDD failure. Here is a link for the free MultiPar program, if you are interested. As for connecting your failing drive and see it spinning up.... well, I guess if you have already given up the idea that you will get anything else off the drive, you could just let the program run either until the program completes whatever it is doing, or the drive dies and becomes unreadable. When I first got into DrivePool, I had some HDD issues with older drives and decided to buy Hard Disk Sentinel after trying the free version. The free version will monitor your drives and alert you to possible failures, and if also offers a bunch of free diagnostic tools, but the paid version has a feature that allows you to "fix" certain HDD issues and continue to use that drive. I was able to "save" a couple of my HDDs using Hard Disk Sentinel's paid version, so I figure I got my money's worth out of the program with my first HDD "save." A couple other drives died hard and there was no saving them. Even though I was able to "save" a couple of my drives with Hard Disk Sentinel, I still replaced them as soon as possible. In my experience, a failing drive will continue to fail until it crashes completely. But I was able to buy time using Hard Disk Sentinel and did not lose data on those "saved" drives before I replaced them. Finally, the Service Log can be found by clicking on the upper right icon Settings>Troubleshooting>Service Log... Hope that helps.

Sounds like a free space issue to me, too. It may have something to do with your settings. For example, under Balancing>Balancers>SSD Optimizer there is a section where you set the "Fill archive drives up to:" and my DrivePool is set at 90%. But maybe your limit is much lower. On a larger HDD, it is possible to have lots of free space left on the drive but maybe your set limit is preventing use of that drive(s). I'd check all those limit settings to look for anything that stands out. There is also another option to check off below that "Fill archive drives up to:" called "Or this much free space" which I have set on 100 GB free per drive. I am running mostly 4TB HDDs on my DrivePool, so 90% limit would mean that 360GB would not be used per 4TB drive. So I set the optional free space setting to 100GB per HDD. I suspect this means that DrivePool will first fill up all my HDDs to 90%, and then continue to add data to the drives until it reaches that 100GB free limit. DrivePool works great for me, but I have noticed that when I get to my free space limits on the drives, unexpected things happen. Well, probably unexpected to me, anyway. Adding another drive to DrivePool usually solves these free space problems as DrivePool will rebalance itself and usually correct those free space issues. Another thing I occasionally do is to move data off to offline backup drives and/or delete data that I no longer want. You might try and temporarily move some data off of DrivePool, have DrivePool rebalance itself and clear the errors, and then move the data back on to DrivePool. Most of my errors are related to Duplication Inconsistency and those errors usually show up when DrivePool reaches its set storage limits. Adding another Archive drive to DrivePool usually solves most of my problems. I have used many different drive pool systems (RAID, Storage Spaces, DrivePool) and they almost always want you to add another drive when free space hits the pool limits. All these drive pool systems seem to work better when they have lots of free space to use. So I hope you find the cause of this error message and can correct your issue.

I ran into a similar situation recently, only my SSD ended up with 2 different PoolParts!? What I did was to manually move my data off the older PoolPart on that SSD to the newer PoolPart on that same SSD, and DrivePool seems to be OK with that solution. I then deleted the older PoolPart folder on my SSD. Everything seems to running OK, but I won't swear that was the best method to clean up the old PoolPart. But it is similar to your situation, so I hope this helps.

I don't use the File Order Placement on my DrivePool, but as I understand it, you can order your drives in the priority they should be used. If you designated your 12TB Seagate Exos as the last drive to be used in the pool, that should significantly reduce the writes to that drive as long as your other drives with higher priority have free space. At the same time, you could also manually transfer files to/from your 12TB Seagate drive when you want. If you have files on the 12TB Seagate that you constantly need to read, then I would manually move them to another drive. If you have lots of frequently used files to move off the 12TB Seagate, then you might consider to "Remove" the drive from DrivePool, have DrivePool empty its data from your 12TB drive, and then add the 12TB Seagate back in again to the pool as the lowest priority drive in the pool. Then you could manually move rarely used files to the empty 12TB Seagate and basically have the 12TB drive there as storage. I think that would work. I'll be reading this thread to see if there are other ideas.

If I understand you correctly, you want to know what advantage adding an SSD to DrivePool v2.2.5 would add to your setup. In your case, since all your pool drives are already SSDs, I don't think you would see any advantage to designating an SSD as a front end cache because all of your SSD drives probably have about the same read/write speed. In my setup, I have 19 USB 3.0 HDDs as Archive Drives (much cheaper, but also much slower, than SSDs) and then I added a single ~250GB SSD as my front end cache for DrivePool. When I write a file to DrivePool, it first goes to my SSD (very fast) and latter when DrivePool "rebalances" it moves the files off the SSD to the much slower Archive USB 3.0 HDDs in the background. In my case, the SSD front end cache significantly sped up my DrivePool writes. If the file(s) is still in the SSD cache when I read it, it will also speed up the read process. However, by the time I want to read any of my files in DrivePool, they are almost always flushed to the Archive drives by then so my read speeds are limited by the transfer rate of my USB 3.0 HDDs. I use my DrivePool primarily as a home media storage server, so the speed of my read rates are not critical. The SSD front end cache allows to me quickly transfer files to DrivePool and then move on to some other tasks. If, at some point, you decided to add non-SSDs to your DrivePool as Archive drives - to save money, maybe - then you would see an advantage to designating one or more of your SSDs as a front end cache for DrivePool. That way, if you write a file to DrivePool, it will always go to the SDD front end cache first at SSD speed. If not, DrivePool will attempt to balance the pool drives and maybe write directly to your Archive drive(s) at their non-SSD rated speed - which would be much slower than your SSD drives. I only mention this because my DrivePool storage continued to expand beyond my initial setup and I bought non-SSDs to save money.

I have DrivePool running on my home media server computer. It normally does not have a monitor attached. So I access and control DrivePool from my other computers using the DrivePool Remote Control app features. One of my laptop computers recently died and I had to replace it. When I installed the DrivePool app, initially it would not accept my license. A quick email to DrivePool Support solved that problem and now the app is running on my new laptop. However, it does not see I have DrivePool already running on my network. On the "Manage a different computer running StableBit DrivePool" banner, the only option I have is the new laptop itself. It does not list my server with DrivePool running on it. The new laptop is running Windows 10 Home, whereas my other computers all have Windows 10 Pro. I don't know if that makes any difference. I have checked and made sure that the Stablebit DrivePool program has Private permission checked to go through the Firewall by Defender - the same setting on all my other computers. My DrivePool on the server is showing up in the network share as Drive J: and I can transfer files without any problems. I just can't get the DrivePool Remote Control app to work on the new laptop. Any thoughts or suggestions welcomed. Thanks.

I have never experienced your problem of files getting corrupted when moved off the cache drive to the archive drives in the pool. I have never used the DrivePool Verify After Copy feature because I have not had the issues you are reporting. I don't know how DrivePool would respond if a verification failed, but I suspect it will alert you and will probably leave the file on the cache drive and try again the next time it balances. But, I really don't know as I have never used that feature. I once had a problem with a USB 3.0 HDD caddy and transferring files into/from DrivePool. Files were getting corrupted in that transfer and I solved that issue by plugging the caddy into a USB 2.0 port and slowing all the transfers down. For some reason, my corrupt file transfer issues went away with USB 2.0. Maybe the caddy had a buggy USB 3.0 engine? I would still encourage you to use something like MultiPar with verification files to narrow down your issue. If you had a test folder(s) with files and .par2 files, you could verify the folders first and then transfer those files to your DrivePool cache. You could immediately run a verification on the files in cache to see if they transferred without corruption into DrivePool. Then after the cache flushes to the archive drives, run the verification on the folder again using the .par2 files. In that way, you could verify the files on your initial device or computer, in the DrivePool cache, and in DrivePool archives. Also, you might consider trying a different interface cable on your archive drive to see if that makes a difference. Cables can go buggy and cause intermittent corruption. Just enough to drive you crazy because you probably can't verify it was a bad cable unless a different cable solves your issue. Good luck. I hope you find the solution to your corrupted files issue.

I have not experienced your specific problems, but I have a few things I might try. You might want to turn on the verify after copy option. Goto Settings Cog>Troublshooting>Verify After Copy. This feature is normally turned off because it will slow down your system. However, in your case with suspected bad copies, it might be worth it to check out that feature. I use the free program MultiPar to create .par2 files for file verification and rebuild. In your case, you would tag the movie file, or folder, and create .par2 files. When you run MultiPar on the .par2 file, it will verify if the original file is intact or if it has been damaged. If damaged, it will attempt to repair the file(s) with the .par2 files you created. You can adjust the % of .par2 files for rebuild anywhere from 0% (index only) to 100% complete blocks for total rebuild. I have my MultiPar set to 10% .par2 files which is enough to verify the file(s) in the folder and will rebuild some damaged and lost files. Of course, I would recommend a good offline backup plan. If your files become corrupt, and MultiPar cannot rebuild the damaged files with the .par2 files you created, then you can pull the backup files and reload them. I really don't understand why DrivePool would be corrupting your files when it balances the pool, but maybe some of these ideas will help you narrow down the cause of your problem.

My DrivePool SSD as a front end cache has been working just great for about 1 year. However, I recently experienced something with my computer that reset my DrivePool settings, removed the SSD cache, and spent weeks telling me that Duplication was inconsistent. Since DrivePool was in an error state, I attempt to use "Troubleshooting" and recheck duplication. Never fixed itself. Thinking my DrivePool was reaching its max capacity, I added another 4TB drive to the pool and within couple days DrivePool was able to fix the Duplication inconsistent situation. So I added my SSD drive back into the pool, as an SSD, and reset the settings to where I think they were set before I had the problems. Unfortunately, my SSD cache no longer flushes to the archive disks as expected. Before, I had the SSD set to flush at 100 GB and had no problems. Furthermore, if I wanted to force a flush of the SSD cache, I would just tell DrivePool to rebalance itself and it would flush the SSD cache to the archive disks. Now, DrivePool will write to the SSD cache, but it does not flush the data to the archive drives when it reaches the 100 GB limit, and when I attempt to force a manual flush of the SSD it will not work. So my SSD eventually reaches a point where it is almost full and then new data will be written to any drive on the pool with the most free space. Something got broke and I don't know how to fix it. For the time being, I have to manually "remove" the SSD to flush the cache and then add the SSD back to the pool. Although this is a viable work around, it is not a solution to my problem. A SSD cache that will not flush itself automatically is not really a cache. Any suggestions would be much appreciated.

I have not had your problem. However, when I do have any problems with the DrivePool UI on my server, I usually just restart the server and the problem(s) seem to go away. If that does not work, I might suggest uninstalling/reinstalling DrivePool with the latest updates. Failing that, I would suggest contacting support and open a ticket. Like many issues, you might not know if this a Windows OS issue or something to do with the DrivePool UI itself. FWIW, I have experienced unexpected results on my programs after Windows completes an update. But usually a reboot solves these temporary issues. Hope you get your problem fixed.

If you want to protect your data, then you really need a good backup plan. IMHO, no online pool system - RAID, DrivePool, etc... - is adequate to protect your data. But that is just based on years of having these online systems fail and data not backed up being lost. As to your specific concerns: 1. RAID 1 - takes a lot of HDD to mirror your data. Does everything in your pool need to be duplicated? If not, then RAID 1 may be too costly as your pool size grows. 2. DrivePool w/ Duplication - I only have a few directories selected for duplication in my DrivePool. Duplication in DrivePool is not designed to be a backup solution. It is there if you have a HDD failure and you could probably recover the pool faster from the duplicate copies. However, if you have some kind of file corruption, DrivePool cannot tell you if the original or the duplicate copy, or both have been corrupted. 3. DrivePool w/o Duplication + Scanner - Scanner might be able to save your data is the HDD has signs of pending doom and there is time enough to evacuate that drive. However, in my experience, with these newer larger TB HDDs, you might not have enough time to evacuate the drive before it fails hard and loses all data. I had a couple HDDs that were starting to fail and they were able to be evacuated without data loss. Hurray! However, I had a couple other drives that alerted and died within hours with no where near enough time to evacuate the drives. Lost data on those drives. Good thing I had a backup plan and archive HDDs stored elsewhere. Other options to consider.... 4. DrivePool with SNAPRaid - there are a number of people using DrivePool for their main data and SNAPRaid to offer recovery options. I personally don't use SNAPRaid because I have very little data on my DrivePool media storage center that needs that extra protection. But maybe your situation is different. 5. DrivePool with MultiPar - This is my method. I use Multipar to create 10% .par2 files for folder verification and rebuild. For my applications, 10% .par2 files is enough for me to verify if the files are still all there and intact, or if some of the files are missing or damaged, then there is probably enough .par2 file blocks to rebuild the damaged file(s). You can set the .par2 file setting all the way up to 100%, but then you would probably be better off with DrivePool duplication or RAID 1 options. I prefer to use MultiPar on my album folders, because DrivePool will send your album tracks to any number of HDDs in your pool. If you lose a track or two from a HDD failure, then MultiPar will fail verification and attempt to rebuild the missing files. Since I have all my data backed up on HDDs I keep in the closet, I don't really worry too much about lost data and if there are not enough .par2 blocks to rebuild the folder, then I'll just pull out the archive HDD and reload that album if I still want it. DrivePool itself cannot tell you if the folder is intact with all associated files, and if the data was damaged somewhere, then your DrivePool duplicate copy might be damaged as well. MultiPar will tell you if the files are verified or not, and you can decided what to do after that. Anyway, good luck on setting up your system.

Don't have an answer to your question, but just noticed that my DrivePool balancer settings were automagically reset and my SSD was no longer working as my front end cache. So, I am trying to figure out what caused DrivePool to lose its settings. I have spent the past few days trying to tell DrivePool that my SSD is not an archive drive, but it still treats it the same as all my archive drives. I don't know why my settings were changed, but I'm having a problem getting DrivePool back to where it belongs.

That's a nice looking chassis you have. 45 HDD's - nirvana! But let me say that I really don't know much about your type of setup because I have never used one. What has me most confused is that your card is for a RAID system. Do you have your controller card and chassis to run in a RAID system, or are your drives listed separately in file explorer? AFAI, DrivePool was designed to work with regular NTFS drives in a non-RAID environment. I have about 19 HDDs connected via USB 3.0 on my system, and it works fine. But I do not know how DrivePool would talk to a RAID controller. So I might be totally off base, but since nobody else has chimed in on your concern, I would be looking at RAID card and maybe that is slowing down your transfer speeds. FWIW, my USB 3.0 drives can transfer data about 120 MBs from my SSD to the archive drives. All my USB 3.0 drives are standalone drives, but I don't have drive letters assigned to the pool drives because DrivePool does not require drive letters. I hope someone can help you. DrivePool is a great software program, but I suspect you might have a hardware issue somewhere with your setup.

My MediaSonic 4-disk ProBox bit the dust last week. So 4 HDDs in my DrivePool were reported as missing. For better or worse, my DrivePool is now up to 19 HDDs (via USB 3.0) and sitting at about 80TB. I was able to remove some HDDs from USB enclosures I had in storage and finally got those 4 missing HDDs from the pool back online. However, DrivePool is not liking the new pool setup. After the missing disks were put back online, DrivePool measured the pool, which seemed to go OK. But then it did a duplication check and erred out on that task. So I forced a trouble shooting duplication check and for the past 2 days, DrivePool has been Measuring... Duplicating... Calculating... etc. With an 80TB DrivePool, it appears that a task is working on the animated status bar flashing, but I have absolutely no idea what % of the task is complete, or if the task is hung up and not progressing. It can be flashing the exact same task on the status bar for hours and hours, overnight, and into the next day. I have just been letting it run on it's own, because in the past I have seen that DrivePool does eventually seem to correct itself - it just might take a very long time. And with an 80TB DrivePool, I am seeing that it is taking over 48 hours and still counting. My suggestion is to add a percentage complete display to the task bar so a person can verify the program/task is still working and not hung up. FWIW, I know all my data is still safely on the HDDs that were in the ProBox. I really don't care if DrivePool takes a long time to correct itself (with an 80TB DrivePool) as long as the task is eventually completed. I just want to be sure that everything is still moving forward and not hung up in a death loop.

@Rob Manderson, Thanks for the offer. Attempted to send you a PM with some info.

My ~10 year old MediaSonic ProBox died today. Will no longer recognize the USB interface. So my DrivePool is now down hard because I have 4 drives offline. At first I was just going to replace the old MediaSonic ProBox with a new one. However, current price on the MediaSonic ProBox is now close to $200. When I bought my ProBox, it was $50. OK, sticker shock. But this leads me to question other options. Individual USB enclosures are around $25, so about $100 for 4 enclosures to replace the ProBox. Have also looked at dual docking stations for about $36 each, or $72 for my 4 drives. Are there other options I have not considered? Don't know if anyone here has some recent advice on enclosure purchases, but would appreciate any help in deciding how to move forward. Thanks.

Follow up: I moved my CineRaid USB Docking Station to a USB 2.0 port instead of a USB 3.0 port, changed the TeraCopy default from asynchronistic mode to OFF, and checked the default copy/move command to verify. Since then, I have had no further problems. I suspect the main benefit was moving the USB Docking Station to USB 2.0 and just slowing down everything. But that is just a guess. At any rate, I no longer have the problems I was complaining about in this post.

I don't think DrivePool would like to see 2 hidden directories with the same directory names. If you took the HDDs offline, I think you could simply cut and paste the whole hidden folder within the drive containing 6TB of information, and then only connect the new drives back into DrivePool. IIRC, DrivePool only checks for the hidden PoolPart directories and does not care what the HDD serial number or name is. But you don't want 2 HDDs with the same hidden directory names. +1, that is how I would go about this transfer. Then I would "remove" the old drives using the remove command in DrivePool and let DrivePool clean itself up. That has happened to me, too. So I have one computer without DrivePool on it and that is how I perform any and all "offline" tasks with DrivePool HDDs.

I'd like to have a 256PB disk, too! If upgrading to 2.3.0.1244 Beta does the magic, I think I'll upgrade now! More seriously, I have not seen this issue with v2.2.5.1237 Stable, so let's just hope it's a beta issue that can be worked out before final release.

What is the size our backup system file? Is it possible to write the backup file to your system HDD first, and then transfer it to DrivePool? I have never seen the Status_Wait_1 error you mentioned, but I don't use the "old" Windows Backup System in Windows 10 (Labeled as Windows 7 Backup) that you mentioned. I have used some other backup software, and it worked fine on DrivePool. Assuming you have at least one pool drive that can accept the complete system backup file, I don't know why the process is timing out on you. But I have never tried to write a file that takes an hour or two to complete.

I don't have an answer. I have never seen this error. I'm signing on to see if anyone else knows what is going on.

In theory, you should be able to run chkdsk on your drives without negatively affecting DrivePool. In fact, I have seen DrivePool recommend running chkdsk on HDDs if it detects some problems. In most cases, chkdsk will find and repair problems without any problems. Having said that, I once ran chkdsk on a DrivePool HDD and chkdsk wiped out the directory on that HDD, so it was basically an empty disk after it ran its task. So those contents were gone from everything, including DrivePool. My lesson learned was that if I needed to run chkdsk on a DrivePool HDD, I will now empty the HDD to the pool using the remove command in DrivePool, and then run chkdsk on the HDD, fix any repairs, and then add that HDD back to DrivePool. This, of course, takes a lot longer to accomplish because the remove command in DrivePool can take hours and hours on a large drive. However, it takes me even longer to replace the contrents of a HDD if chkdsk blows its mind and essentially reformats the drive during the chkdsk task. When you tell Windows to automatically fix your HDD with chkdsk, you don't have any more control over what it does at that point. I don't know if my answer is of any help, but I hope you heed the warning and don't experience data loss like I did. Chkdsk is a Windows task and has nothing to do with DrivePool. If chkdsk runs without any problems, all your data will still be there for DrivePool.

I had a similar goal, but use a different method than what you suggest trying to do with DrivePool HDDs. I added some numbers to your requirements for discussion. First of all, I don't think DrivePool is capable of performing #1-#4 like you want. [1] As soon as you remove a drive from DrivePool, the pool goes into a missing disk routine and the pool becomes read-only. [2] DrivePool will scatter files over various HDDs in the pool. So, if you have an album of 15 tracks, you might have 10 tracks on HDD01 and maybe 5 tracks on HDD03. DrivePool does not split a file, but it will split folders. There are some plugins that, in theory, that will write all files to one HDD until full, then move on to the next HDD in the ordered list. But there are a number of overrides that can happen and I would not completely trust a plugin to keep folders complete and not split files in a folder to other HDDs in the pool. [3] Yes, if you remove a HDD from the pool, the files on that drive will be removed, but only so far as DrivePool reporting that the HDD is missing and locking down the pool into a read-only mode. I don't think you want that. [4] DrivePool does not split a file. So any files written to a HDD will be the complete file. But that does not mean that your folder(s) will be complete as the files may be split over any number of HDDs in the pool. As to [5], you can take any DrivePool HDD and attach it to any other computer and still be able to read the files in the hidden PoolPart directory. Since DrivePool writes complete files to the HDD, the files on that HDD are complete and can be read by any computer. However, the folders might not be complete, as mentioned before, so you might only have 10 tracks of the 15 tracks of the complete album folder. But, those 10 tracks would be complete. Again, I don't think this is the solution you are looking for. MY METHOD: Here is how I manage my DrivePool data. I have my DrivePool data up and running all the time. When I want to backup or archive any data for offline storage, I pop a HDD into a disk caddy and transfer files from DrivePool to the HDD in the disk caddy using TeraCopy with verification. In that way, DrivePool will read and consolidate all the data from the pool and transfer the complete files and folders to the HDD in the disk caddy. When the HDD in the disk caddy gets full, I label it for storage and put it in my closet. This method ensures [1] the pool is accessible all the time. [2] DrivePool will consolidate and transfer all selected files/folders to the HDD in the disk caddy. [3] If you choose to move the files from DrivePool to the HDD in the disk caddy, then those files will no longer be in the pool freeing up space in DrivePool for other data. [4] I use Teracopy to verify all archive moves. So DrivePool will write the file to the HDD in the caddy, and if the newly written file passes the verification checksum, then, and only then, is the file removed from DrivePool. [5] The HDD in the disk caddy can be removed and placed in any other of my computer systems and it reads just fine as a standard NTFS file formatted HDD. I think my method achieves your main goal without the problems inherent in removing HDDs from DrivePool. I currently buy bare HDDs which is why I use the hard disk caddy. In the past, I have also used USB HDDs for backup/archive purposes in the same manner. I know my method works for me, but I suspect your proposed approach to removing and adding drives to DrivePool will not work as you want.