Good afternoon all,
Just to give you an idea where I'm coming from, I stumbled upon FreeNAS and ZFS while looking into a way to checksum and verify the integrity of my archived data (home/personal use -- maybe 6TB total if I give plenty of room for expansion). My thought was that I would either create or use an existing solution to put text files with MD5 checksums in every directory that has "important" documents in them. That way, I could set up some automated task to read the MD5 files, check the files, and let me know if there was any kind of discrepancy.
From what I've read so far, ZFS does this and more automatically as part of its normal operation. This sounds really good to me, but then I've read some other things that make me nervous. Let's just get this out of the way -- I'm convinced that my NAS build will include ECC RAM, so no worries there. However, in my above "manual MD5" scenario, I don't think bad RAM would be as likely to threaten the entire store. Bad RAM would be discovered during the verification process, or maybe while writing a file then trying to read it back, but it would be less likely to do more damage than that because it lacks any kind of self-healing feature.
It makes me wonder if there are any other types of scenarios, aside from bad RAM, that would be potentially more damaging than it would be on a traditional file system, such as power failures, a bad software update, etc. A bad software update is (hopefully) unlikely, as long as I stick with a stable release that's been in use for a while, but I could see some power failures happening. Is ZFS less resilient than other file systems in this respect? Is it really "all or nothing" if some areas of the disk have been compromised?
A lot of what I read says, basically, that the NAS should not be your only backup (i.e. "You do have backups, right?"), but the truth is that this will be my backup for files that are on my computers at home, and I'd like it to be reliable. If ZFS is as likely to fail as a "normal" filesystem like NTFS/EXT3/4 due to power issues, etc., but there are no tools to recover the files from a corrupted ZFS store, then I'm thinking that I might actually be better off with a more traditional filesystem since I cannot guarantee completely against power failures.
Thanks for any insight into this!
Just to give you an idea where I'm coming from, I stumbled upon FreeNAS and ZFS while looking into a way to checksum and verify the integrity of my archived data (home/personal use -- maybe 6TB total if I give plenty of room for expansion). My thought was that I would either create or use an existing solution to put text files with MD5 checksums in every directory that has "important" documents in them. That way, I could set up some automated task to read the MD5 files, check the files, and let me know if there was any kind of discrepancy.
From what I've read so far, ZFS does this and more automatically as part of its normal operation. This sounds really good to me, but then I've read some other things that make me nervous. Let's just get this out of the way -- I'm convinced that my NAS build will include ECC RAM, so no worries there. However, in my above "manual MD5" scenario, I don't think bad RAM would be as likely to threaten the entire store. Bad RAM would be discovered during the verification process, or maybe while writing a file then trying to read it back, but it would be less likely to do more damage than that because it lacks any kind of self-healing feature.
It makes me wonder if there are any other types of scenarios, aside from bad RAM, that would be potentially more damaging than it would be on a traditional file system, such as power failures, a bad software update, etc. A bad software update is (hopefully) unlikely, as long as I stick with a stable release that's been in use for a while, but I could see some power failures happening. Is ZFS less resilient than other file systems in this respect? Is it really "all or nothing" if some areas of the disk have been compromised?
A lot of what I read says, basically, that the NAS should not be your only backup (i.e. "You do have backups, right?"), but the truth is that this will be my backup for files that are on my computers at home, and I'd like it to be reliable. If ZFS is as likely to fail as a "normal" filesystem like NTFS/EXT3/4 due to power issues, etc., but there are no tools to recover the files from a corrupted ZFS store, then I'm thinking that I might actually be better off with a more traditional filesystem since I cannot guarantee completely against power failures.
Thanks for any insight into this!
front to back, making notes on the subjects you might use and search and ask the forum & google everything that is not clear. You will benefit from that later.
