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Umfriend

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Posts posted by Umfriend

  1. I really wouldn't know but I would wonder whether you'd be better off just using DP with x2 and a CloudDrive or a real backup solution. I am not familiar with SnapRaid but in your setup, as far as I can tell, you'd have data stored in Pool 1 and Pool 2 and then have both duplicates protected by parity. So, you'd use more storage capacity then either a simple x2 duplicaiton or x1 duplication + parity setup.

    You have single files in excess of 1TB? Anyway, it would then simply write to the archive things.

    BTW, if it is a NAS, what kind of network do you have? If it is "just' a 1Gb network, then there really is no need for SSD caches.

    On streaming and Snapraid I can't be sure but for the storage/DP part, a simple Celeron with 4GB would do the job even.

    Oh, and did you have a look at Scanner?

  2. Within Scanner you can do: Settings -> Scanner Settings -> Open Advanced settings and troubleshooting -> Advanced Settings -> Scanner - ScanMaximumConcurrent and set to a high(er) number. I think that would allow you to scan many disks at the same time.

    Having said that, I set Scanner to scan every 14 days and have ensured that the drives are all scanned at different days. Other than for a quick first scan, I would prefer scanning my collection to be distributed over time.

  3. So in DP, there are a number of balancers. One of them, by default, is Stablebit Scanner. If you de-activate that one then DP will not migrate (you can also set parameters within that balancer to determine what kind of things would cause an evacuation). Having said that, if the number of unstable sectors increases then I would want to make sure I had enough space to replace. I would be comfortable with 2 sectors but force Scanner to re-scan and if that number increases then, yeah, probably a good idea to at least add a disk. Whether this disk needs to be taken out depends on preferences, duplication and backup situation.

    BTW, the evacuation will never itself cause data-loss. If there is not enough space to move then either nothing will be moved or as much as possible basically.

  4. I do not have SnapRaid but from what I have read, I think I would have done it as follows (I am assuming that DP is set not to rebalance because that might cause a lot of files being from other drives even to the new 12TB drive):

    1. Add net drive to Pool;
    2. Stop DrivePool Service;
    3. Robocopy from the old drive everything *within* the hidden PoolPart.* folder to the hidden PoolPart.* folder on the new drive;
    4. Either delete from the old drive or physically disconnect/remove it;
    5. Change Snapraid config file;
    6. Restart DrivePool Service (or reboot pc);
    7. Remove old drive from Pool (through DP GUI).

    Or somesuch.

  5. Well, it does indeed need such a list. But rather then keeping its own list, it uses the standard NTFS database on the underlying drives. Now I am not the developer but my guess is that whenever DP balances, it DP simply queries the underlying Drives for the data on the files.

    Edit: Also, keeping a seperate database up-to-date may actually be quite burdensom as a user may alter files in the Pool without going through DP by operating on the underlying drives.

  6. No, DP does not know which files are on a lost/disconnected/removed drive. For that it would have to maintain some sort of database which, to my mind, goes against the idea of a lean and "simple' app. Having said that, there is the DPCMD command line app that does create a list of all files in the Pool. However, that is a snapshot only.

  7. I think you can. Just be sure you stop the drivepool service prior to doing this (and I am not even sure this is necessary, but I would) and restart service (or reboot) after you finish. Assuming Disk Management does not screw up, the data should be safe in any case because everything is stored in plain NTFS format. Of course, a backup never hurts. An alternative is the free version of EaseUS Partition Manager..

  8. You could use Hierarchical Pools. Say you have disks A, B internal and C is the external one. You can then:
    1. Create a Pool Q consisting of A and B, no duplication
    2. Create a Pool R consisting of C, no duplication (*)
    3. Create a Pool P consisting of Pools Q and R, x2 duplication.

    However, I don't think there is a good way to deal with temporarily removing drives. AFAIK, if you then (physically) remove/disconnect drive C, DP will put Pool P in read-only mode. May be what you are looking for but I'm not sure that will always work out well. Moreover, is that a USB connected drive? AFAIK, using USB-connected drives is not considered best practice and IIRC, it has led to problems, including data loss, due to connections over USB sometimes dropping for a bit (which I think is still within spec for USB).

    (*) you could also create Pool P with Q and C, so without the intermediary step of Pool R but I think it makes it a bit harder to manage when removing/adding.replacing drives.

  9. 7 minutes ago, vfsrecycle_kid said:

    Maybe not immediately, hence why I said "can it calculate" - I'm aware it wouldn't instantaneously know and re-measuring is necessary.

    - Losing a disk - can the existing drives hold all the data and retain replication property (pool was not full)
    - Losing a disk - how big of a drive do you need to replace it to retain replication property (pool was full)

    My thing is DP should be able to figure out both BEFORE duplicating simply fails from lack of disk space. Right now all you get is a percent of duplication progress and for rebuilds that take multi-day you don't want it to randomly fail at 32% and it takes days to notice (yes, some people actually use this on their servers and don't check it daily)

    Also regarding the math, I've edited my post. This proves I can't even trust myself and I'd much rather trust what DP tells me. Thanks for the correction.

    Actually, I think you are right. Once DP has worked-out which files should go where (I think that happens when DP status bar says "building bucketlist"), it should at that point be easy to see if there is space enough. I would still want DP to go ahead, because it has to happen anyway, but perhaps send out a mail or somesuch indicating that more space is needed. Then again, it is coding for something that is, I think, rarely an issue. Once you need to replace a drive, insert on of at least equals size. That is, I think, by default what most would do anyway.

    I run DP one a WSE2016 server BTW.

  10. Actually, once a drive is lost, it would take quite some time to determine how much would be needed to re-establish the required duplication. DP would not have been aware or remember what was stored on the lost drive. The first step is called re-measuring (try it). And yes, as a result of that, DP might be able to give a recommendation on how much, if any, additional storage is needed. But practically, if you know the size of the lost drive, then all you need to know is: how much data was on it and how much do you have available now.

    Your math does not work out BTW. After the failed drive, you have 4TB of duplicated data (using 8TB) and 4TB of unduplicated data and you would need a 4TB drive.

  11. If you want to replace, the best way, IMHO, is to:
    1. Add a new drive to the machine and Pool
    2. Remove the faulty drive through the GUI of DP
    3. Let DP do its magic (may take a while)
    4. Remove the faulty drive from machine.

  12. No. If, and only if, the entire Pool had a fixed duplication factor then it *could* be done. E.g., 1TB of free space means you can save 0.5TB of net data with x2 duplication or .33TB with x3 duplication etc. However, as soon as you mix duplication factors, well, it really depends on where thre data lands, doesn't it? So I guess they chose to only show actual free space without taking duplication in mind. Makes sense to me. Personally, I over provision all my Pools (a whopping two in total ;D) such that I can always evacuate the largest HDD. Peace of mind and coninuity rules in my book.

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