I have been looking at DrivePool for sometime and as I get closer to a new build I had some things I wanted to verify:
1) Drive pool will work with backblaze and I can backup my pool just as if it was a normal HDD.
2) It is not possible to have real time duplication enabled and only use a single physical SSD for caching. (I wish you could just use a single drive as a literal write cache where it taking the data off the cache as fast as it can and placing it on a pool with real time duplication, in this way your SSD functions the same as the DDR cache on a raid controller where there is no duplication in the DDR.)
3) Close to real time duplication is possible when using a single physical SSD for caching. Can I still have real time on the drives it is writing to? How close to real time can we get?
4) Can not preform a single move operation that is larger than the SSD cache to any pool using said SSD cache. Now I use terracopy so I can override this and preform the move operation anyways but what will occur in this case? What if I am moving a single file that is larger than the SSD cache?
5) Read operations take advantage of multiple drives and can do so at the block level. If I have a large file that is on a pool containing 2 drives with duplication it will read the file from both drives. If I had a file on a pool with duplication and 4 drives (assuming there is only 1 duplicate) it would read at the same speed because the file is only stored on 2 of the 4 drives and thus read speeds are limited by the number of duplicates and not the number of drives in the pool (as compared to raid 10).
6) In a raid 10 like pool where you have at least 4 drives and file duplication on if you were to lose two drives at the same time and those drives were duplicates of each other there is no function of the program that can tell you what files you have now lost. (This seems like something that would make a great feature)
7) Possible solution to ensure you have backups for the scenario in #6 would be to have backblaze backup each duplication pool individually so that if you lost all the drives in that pool the restore is very simple. A problem with this is that windows can only have 26 drive letters. Thus you could have a maximum of 24 duplication pools 1 pool of the duplication pools and your C: drive. Perhaps it is possible to get around this if you link a duplication pool to be a folder on your C drive, I am not sure if Backblaze would follow it. Basically at minimum for example I could do the following:
Create duplication pool named "D Pool 1" of >=2 drives and assign it to drive Z
Create duplication pool named "D Pool 2" of >=2 drives and assign it to drive Y
Create pool containing D Pool 1 and D Pool 2 and assign it to drive D
Set backblaze to backup drive Z and Y (can it do this or will it fail to see the files?)
Now if you lose a duplication pool that was part of a larger pool it is easy to pull a backup of just that D Pool # from backblaze. In this way you do not need to worry about what files from the larger pool are missing because those files are in their own backup. If you have the freespace you can simply restore the files from your D Pool # backup to your larger pool and bam all your files are there now.
Sorry for so many questions, I just want to ensure that my understanding of how DrivePool operates is correct so that I am able to plan accordingly.
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zeroibis
I have been looking at DrivePool for sometime and as I get closer to a new build I had some things I wanted to verify:
1) Drive pool will work with backblaze and I can backup my pool just as if it was a normal HDD.
2) It is not possible to have real time duplication enabled and only use a single physical SSD for caching. (I wish you could just use a single drive as a literal write cache where it taking the data off the cache as fast as it can and placing it on a pool with real time duplication, in this way your SSD functions the same as the DDR cache on a raid controller where there is no duplication in the DDR.)
3) Close to real time duplication is possible when using a single physical SSD for caching. Can I still have real time on the drives it is writing to? How close to real time can we get?
4) Can not preform a single move operation that is larger than the SSD cache to any pool using said SSD cache. Now I use terracopy so I can override this and preform the move operation anyways but what will occur in this case? What if I am moving a single file that is larger than the SSD cache?
5) Read operations take advantage of multiple drives and can do so at the block level. If I have a large file that is on a pool containing 2 drives with duplication it will read the file from both drives. If I had a file on a pool with duplication and 4 drives (assuming there is only 1 duplicate) it would read at the same speed because the file is only stored on 2 of the 4 drives and thus read speeds are limited by the number of duplicates and not the number of drives in the pool (as compared to raid 10).
6) In a raid 10 like pool where you have at least 4 drives and file duplication on if you were to lose two drives at the same time and those drives were duplicates of each other there is no function of the program that can tell you what files you have now lost. (This seems like something that would make a great feature)
7) Possible solution to ensure you have backups for the scenario in #6 would be to have backblaze backup each duplication pool individually so that if you lost all the drives in that pool the restore is very simple. A problem with this is that windows can only have 26 drive letters. Thus you could have a maximum of 24 duplication pools 1 pool of the duplication pools and your C: drive. Perhaps it is possible to get around this if you link a duplication pool to be a folder on your C drive, I am not sure if Backblaze would follow it. Basically at minimum for example I could do the following:
Sorry for so many questions, I just want to ensure that my understanding of how DrivePool operates is correct so that I am able to plan accordingly.
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