long story short. I put on a second parity and somehow it messed everything up and i kept getting drives disabled, one after another even though they were fine and passed the smart tests. This caused me to lose some data because I didn’t want to go through the lost and found and the thousands of folders it was put in. I did pull out all my photos and videos, but the rest was so unorganized I deleted it. Since then, I backed up my server and now I have 8 14tb exos drives waiting on a file system.  I was going to do Raidz2 but then after I formatted it I realized I couldn’t use my cache drive anymore,  

 

That brings me to this forum to ask for your opinions and ask a few questions. I like the idea of snapshots to keep all my data organized and backed up, i like that raidz2 lets 2 drives fail just like dual parity would. What I dislike about parity is that it destroys the folder layout and file system organization if I lose parity and have to rebuild it. 

 

1) if I go back to XFS is there a plugin that snapshots the files and folder systems that way if I lose my parity or drives get disabled again I can recover the data exactly how it was originally? Or a sway to snapshot with xfs?

 

2) If i go ZFS and do a pool for raidz2? is there a way to use a use cache drive? 

 

3) would there be any benefit to using zfs on all individual drives, with parity? Can you use snapshots with it like this? Would I be able to create a share that spans across multiple zfs drives not combined in a pool?  

That is not a short story (<-- that was)

 

Backup (just a note while reading)

 

Finished reading... You need to backup and not "think" that multiple drives give you that.

 

PARITY: Made properly, and a drive fails, goes on like nothing happened. That's what "parity" is for. You can replace the drive and (hopefully) everything goes on and know one even notices.

 

BACKUP: Made properly, and a drive fails because the computer melted from a fire and is a ball of plastic goo.

 

The backup is on completely different drives and you can "restore" your server (after insurance buys you a new one -- assuming you have fire insurance) .

 

In short... Parity keeps things going and Backups ensure you never loose anything.

 

MrGrey.

 

 

It sounds like you might have had an issue unrelated to parity. Adding a second parity drive would not destroy the filesystem or anything like that. In fact parity doesn't know about filesystems; it's literally just 0s and 1s. If you were able to browse to a parity drive, that's all you would see - junk.

 

My guess it adding the second drive exposed an underlying problem, which caused the drives to start getting disabled and then the corruption. Usually this happens from a bad cable or SATA/SAS controller.

 

To try and answer your questions:

1) XFS/ZFS won't help you with disabled drives. That sounds like a hardware problem that you'll need to look into. It's like asking "are blue cards or red cards better to build a tall house of cards?" If the table is wobbly, it'll be the same either way. To your snapshot question though: No, not that I'm aware. There's a plugin (ZFS Master) that can do snapshots with ZFS, but XFS doesn't have this functionality, though there might be something hacky with rsync.

 

2) You can simply set primary storage to your RAIDZ2 pool, and secondary storage to "none". That'll keep files on the pool without moving to the array. There is (currently) no way to move files between two pools though.

 

3) I'm not familiar enough with ZFS master to answer this - I don't know if an array drive formatted with ZFS would appear there - but you can certainly use ZFS functions on the command line to work with snapshots - you can use 'zfs send' and 'zfs receive' for example to sync data between two places. That's my plan as it happens, though I haven't implenented it yet: To convert my dedicated backup drive on my array to ZFS, and snapshot my cache pool datasets to it, instead of my current rsync implementation. You cannot however span multiple drives, as they array doesn't support multi-drive ZFS. Each drive is its own drive.

 

 

Thanks everyone for their reply's. Their was a hardare issue with my lsi, but i think ive fixed it by throwing a fan on it. If i get errors again im buying a sas 9300. As for zfs, i decided to just do xfs again for now and tossed some hard drives in my old readynas and im using that to backup all my important data.  

 

MrGrey thanks for explaining parity and backup. I was using the term backup in regards to parity. I didnt need a true backup, I just wanted a way to recover the data if a hdd or 2 failed and it looks like parity works for me that way on zfs or xfs.

 

On 9/16/2023 at 4:15 AM, -Daedalus said:

You cannot however span multiple drives, as they array doesn't support multi-drive ZFS. Each drive is its own drive.

 

Im a little confused with this. I actually tested it, zfs 6 drives with no pool and parity built fine.  Or were you refering to the snapshots not spanning multiple drives? 

When used in the array each device is independent, with its own filesystem, they can still be zfs but are all sperate 1 device filesystems, for snapshots for example, you'd need to take an individual snapshot of all disks.

On 9/14/2023 at 11:10 AM, buster84 said:

1) if I go back to XFS is there a plugin that snapshots the files and folder systems that way if I lose my parity or drives get disabled again I can recover the data exactly how it was originally? Or a sway to snapshot with xfs?

 

Use Vorta (Borg) or Duplicati.  I like GUI apps better than CLI but with Vorta (Borg) you get both because Vorta is the GUI and Borg is the backend CLI that Vorta uses.  To me a GUI is more intuitive about what's going on.

 

MrGrey alludes to the fact that your backup should be somewhere else, preferably in another location and at the very least outside of the server holding all your data.  It could be another server or just a bunch of hard drives that you update from time to time.

 

In my setup I have two servers.  One (actually three) that are file servers and one backup server.  The data on the file servers is backed up to the backup server with daily snapshots.  Vorta (Borg) and Duplicati use deduplication which is much easier (less strain) on the computer than the deduplication that ZFS uses since ZFS is realtime deduplication and backup apps only need to dedupe the files when they are backed up.