Greg Freemyer wrote:
This email might be offtopic, not sure.
I have a minimum of 10 TB of data I want to consolidate off of multiple USB drives to free them up. The data is almost exclusively static and rarely accessed, but I need to maintain it.
First thought - tape. As you also mention further down.
I suspect I will also want to have more resiliency at some point. (ie. raid 0 => raid 5 => raid 6)
As we are talking very large disks, when one breaks (as they will), you will be running degraded for hours and hours, during which time your data is highly exposed to another disk breaking. RAID6 will take care of that as will e.g. RAID15.
If I truly had confidence in this storage pool I might eliminate both copies of the data that is on USB drives currently. But even with raid 6, I think I would worry about a total LVM or Volume crash Or even a user error!
Tape backup is the only way to solve that.
Even though I know LVM and MDraid somewhat, I don't know if is "dynamic" and "reliable" enough for what I want.
It doesn't sound like you want "dynamic" at all :-) Both lvm and mdraid are very reliable technologies. I use both extensively.
Goals:
- Create a fileserver that I can add drives to from time to time and grow it's capacity. Probably 10TB drives so I don't have too many spindles in the mix. When bigger drives become available, I'd prefer to use them, so being stuck will all the same size drives is a negative.
LVM is the answer to that.
- Performance is non-critical. I've used LTO-4 tapes to do this in the past, but I hope online is a better choice now. With LTO-4, once I had a new data set (typically 100GB - 2TB) I would make a backup with tape and put it away for the time I needed to ensure I still had it. (Often years).
For critical email archiving, we keep three copies - two on tape in secure, geographically separate locations, one on-line. Unless you need quick (even if rare) access to the data, tape is the answer, especially as you're comfortable handling it. For uncritical daily backups and such, I use a plain fileserver, just some xTb drives in RAID1.
- Share the exported volumes with Windows PCs. (Not critical, but preferred)
So samba.
- have the ability to start the drive pool with a single drive and add to it over time
Uh, not sure you can go from zero redundancy to e.g. RAID5 or RAID6 just like that. Some hardware controllers do support it though.
- Allow the added drive to be either as SATA USB3.1
I guess you can do that.
- Allow the Raid "protection level" to be adjusted for a given volume from time to time.
Maybe LVM2 can do that I'm not sure. I wonder why you would want that.
I was actually planning to do this with Windows and its "Storage Spaces" solution. I just this afternoon put a new 10TB drive in a windows PC and added it to the "Storage Space" (like LVM).
But my reading says the "resilience level" of a volume has to be set at the time the volume is created. I can grow it later, but I can't change it from a raid 0, to a raid 1, to a raid 5, etc.
That is almost certainly correct. I doubt if you can do that with LVM either, but this would work with LVM: Monday - volume 'A': single drive with all data. (zero redundancy) Tuesday - volume 'B': add two drives in RAID1, migrate from 'A'. (redundancy increased by 1) Wednesday - volume 'C': add 2+1 (from A) drives in RAID5, migrate from 'B'. (no increased redundancy) Thursday - volume 'D': add 2+2(from B) drives in RAID6, migrate from 'C'. (redundancy increased by 1) -- Per Jessen, Zürich (8.1°C) http://www.dns24.ch/ - free dynamic DNS, made in Switzerland. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org