Btw I haven't caught up on ANY of the past postings yet, was out of town and there was a bunch of talk on some threads here if i'm not mistaken... so if something is redundant advance apologies, I just wanted to sit this out to bake for a little first.
I stumbled across SnapRAID the other week and I think i'm most interested in at least starting there. It may not be on the only NAS box in the house, but I saw a list of features that I really liked. People here probably know way more than me so either please talk me into it being a good choice, or out of it because I don't know enough about other options.
- I like the fact it works over the filesystem instead of under it, meaning nothing gets in the way of say normal drive recovery tools. I can replace a drive by simply mirroring it. I can upgrade a hard drive size by copying all files to a new drive and resynching.
- This also lets me apply my desire to have a redundant array of inexpensive tape. A set of LTO Ultrium tapes, which has one or more parity tapes, capable of restoring all the data in the set even if one or more tapes breaks or becomes irrepairable. Yes I also plan mirroring, but if the wrong two same tapes break somehow in a mirrored set all data gone forever. Parity tapes let me recover that. Since SnapRAID seems to put this all in common files, I can just write the parity files to tape. (provided that LTFS supports stamps with microsecond accuracy which SnapRAID requires apparently)
- I like the fact only one disc spools up at a time, unless you are synching. This minimizes power use and makes me less concerned about using a bunch of drives because they can just sleep most of the time. Since earlier work will mostly be done locally on a PC (with it's own RAID1 on the workdrive) the day's work can be backed up to the NAS and synced from each PC. This is less convenient when work shifts to the NAS I know, it's just to start.
- Easier to buy small and scale out than FreeNAS ZFS. Easy to upgrade drives, add drives, etc. ZFS wants me to buy all the drives for a pool at the start to set up a vdev and makes flying upgrades a PITA, i'm looking for something more like Drobo functionality. (upgrade and add drives whenever) Much much lower system requirements too - a 32tb ZFS system wants 32gigs ECC RAM and not many systems far over that size. 70tb SnapRAID systems are the norm and run in under 8gigs RAM by what I can tell.
- My top priority is not running ZFS but having the main advantages I saw as being an upgradeable storage pool, redundancy, parity, and file integrity verification. SnapRAID doesnt have things like convenient snapshots, undelete, deduplication or any of that, which is why a FreeNAS or other system is probably still an upgrade. I will get there eventually. For now I just need to get started with a better system than I had before. (dumping it on external USB drives to find multiple things silently corrupted or lost by other means) And that is the system that migrates data for tape storage ASAP.
None of this means that my research is complete or over! This is just rather the first system I think I would like to set up. Which I hope to build and have online before anything else - while simultaneously researching the 'future upgrade options' that might be better, more convenient, better production workflow or speed or anything. Heck i'm pretty sure a monolithic ZFS system is better than a SnapRAID of the same size - but it costs more and I cant easily write stuff to tape either, so pretty sure SnapRAID will always be on at least one NAS box to ease data migration to Ultrium LTO tape. Since it will always be here on the disk-to-tape mirror system anyway.
Left unsaid but open to discuss are when I need to migrate to higher performance systems up to and including SANs and such.
Assuming SnapRAID works like I want it to, it gives me a starting point, and makes it less of a holdback for what type of NAS/SAN system to move to in the future.
I stumbled across SnapRAID the other week and I think i'm most interested in at least starting there. It may not be on the only NAS box in the house, but I saw a list of features that I really liked. People here probably know way more than me so either please talk me into it being a good choice, or out of it because I don't know enough about other options.
- I like the fact it works over the filesystem instead of under it, meaning nothing gets in the way of say normal drive recovery tools. I can replace a drive by simply mirroring it. I can upgrade a hard drive size by copying all files to a new drive and resynching.
- This also lets me apply my desire to have a redundant array of inexpensive tape. A set of LTO Ultrium tapes, which has one or more parity tapes, capable of restoring all the data in the set even if one or more tapes breaks or becomes irrepairable. Yes I also plan mirroring, but if the wrong two same tapes break somehow in a mirrored set all data gone forever. Parity tapes let me recover that. Since SnapRAID seems to put this all in common files, I can just write the parity files to tape. (provided that LTFS supports stamps with microsecond accuracy which SnapRAID requires apparently)
- I like the fact only one disc spools up at a time, unless you are synching. This minimizes power use and makes me less concerned about using a bunch of drives because they can just sleep most of the time. Since earlier work will mostly be done locally on a PC (with it's own RAID1 on the workdrive) the day's work can be backed up to the NAS and synced from each PC. This is less convenient when work shifts to the NAS I know, it's just to start.
- Easier to buy small and scale out than FreeNAS ZFS. Easy to upgrade drives, add drives, etc. ZFS wants me to buy all the drives for a pool at the start to set up a vdev and makes flying upgrades a PITA, i'm looking for something more like Drobo functionality. (upgrade and add drives whenever) Much much lower system requirements too - a 32tb ZFS system wants 32gigs ECC RAM and not many systems far over that size. 70tb SnapRAID systems are the norm and run in under 8gigs RAM by what I can tell.
- My top priority is not running ZFS but having the main advantages I saw as being an upgradeable storage pool, redundancy, parity, and file integrity verification. SnapRAID doesnt have things like convenient snapshots, undelete, deduplication or any of that, which is why a FreeNAS or other system is probably still an upgrade. I will get there eventually. For now I just need to get started with a better system than I had before. (dumping it on external USB drives to find multiple things silently corrupted or lost by other means) And that is the system that migrates data for tape storage ASAP.
None of this means that my research is complete or over! This is just rather the first system I think I would like to set up. Which I hope to build and have online before anything else - while simultaneously researching the 'future upgrade options' that might be better, more convenient, better production workflow or speed or anything. Heck i'm pretty sure a monolithic ZFS system is better than a SnapRAID of the same size - but it costs more and I cant easily write stuff to tape either, so pretty sure SnapRAID will always be on at least one NAS box to ease data migration to Ultrium LTO tape. Since it will always be here on the disk-to-tape mirror system anyway.
Left unsaid but open to discuss are when I need to migrate to higher performance systems up to and including SANs and such.
Assuming SnapRAID works like I want it to, it gives me a starting point, and makes it less of a holdback for what type of NAS/SAN system to move to in the future.
