Hello,
Yes, it seems proxmox doesn't allow to spindown disks, so the only solution I found was to passthrough an entire PCIE Sata expansion controller, to OMV, so know I am able to monitor SMART and spin down disks through the VM.
The only problem I am facing now, is that I can spin them down manually through CLI but not automatically through GUI, so just checking what might be going wrong there.
Kind regards
Hello,
Has anyone achieved to spin down hdds in OMV running under proxmox?
I am currently trying to spin some disks, that I passthrough to the KVM VM, but it seems not to be working.
Kind regards
I started reading some documentation of direct_io and decided to give it a try. Write speed shouldn't be affected if I disabled it, but it seems to have solved the problem 
Ok more problems.
Actual default config for Mergerfs seems to be crap. When I copy a file through CIFS/SMB to my mergerfs folder, I get the following speeds (attachment)
But if I copy the same file to one of my 2 actual disks directly, I do not have any write spike.
Do you know how to optimize this? I am currently using the mergerfs plugin:
root@openmediavault:~# mergerfs --version
mergerfs version: 2.28.2
FUSE library version: 2.9.7-mergerfs_2.28.0
fusermount version: 2.9.7
using FUSE kernel interface version 7.29
Kind regards
In past experimentation with BTRFS, I expected to do what you're suggesting; detect bit-rot and replace the corrupted file from back up. The problem I had was, there didn't seem to be any clear way to associate a detected bit error with the name of the affected file. And I spent a bit of time looking around for a process or a utility that could do it - I found nothing.
So, if you find a way to do that (associate a detected bit error to a file name) I'm real interested. Please post that information.
I think there was an option to see what files were the affected ones. But do not remember now. Once I got the information I will post it here, no problems.
But it seems thats the way how UNRAID works. I mean by using BRTFS.
Kind regards
Alles anzeigenThe way you are saying will NOT give bitrot protection. It might provide bitrot detection. Try to not mix up detection, correction and protection. It is confusing.
Try your suggestion. I haven't tried it so I don't know if it will work. Or even if it is possible.
ZFS with redundancy or BTRFS with redundancy gives real time bitrot protection. Snapraid with redundancy gives bitrot protection, but not real time.
None of your suggestions gives bitrot protection. Checksums gives only bitrot detection. You have to provide the correction manually.
Protection=Detection+Correction.
Well yes, sorry, I am only searching for bitrot detection, as I explained earlier, I am not expecting to recover my corruptions or lost of disks by the FS itself, I will do it with my backup, which is for what it is.
You could use a disk volume manager like LVM to "span" several JBOD/independent drives. It is similar to raid0, but more efficient in utilizing the storage. Still I would expect all the drives to spin up.
But does that give me any bitrot protection?
Why not the way I was saying? JBOD of BRTFS and then mergerfs?
Alles anzeigenThere is no JBOD RAID. That is nonsense speech. JBOD is drives NOT combined. RAID is drives combined. Mergerfs is something in between.
Using mergerfs the filesystems on the drives are combined but still exists as separate filesystems. That means that a file is either stored on one drive or the other. If one drive fail, the files on the other drive are still there and can be retrieved as normal.
Using raid0 the drives are combined and one filesystem is created spanning both drives. If one drive fail, the whole filesystem fail. Both drives. Poof! Gone! See you never again...
Performance for a raid0 is most likely significantly higher than for two drives in mergerfs.
Using mergerfs you can use various "policies" to decide on what drive a file end up. If you have a media library with files in subfolders split up on starting letter, you cans say that files starting on a, b or c should be on this drive. Files starting with d, e, f or q should be on that drive. Or you can have a policy that says new files should be stored on this drive first, then on that. Or new files should be stored on the drive with the most free space.
Let me check and I will let you know. I though JBOD was joining also disks toguether. I might have go wrong.
You could have raid0 with BTRFS. Then you get spanning drives and checksums allowing bitrot detection. You don't get bitrot correction. That you will have to provide manually. Bitrot detection combined with bitrot correction equals bitrot protection.
You also need to learn how to use BTRFS. Good luck with that...
No, I do not want to use RAID0, because that will spin all my disks once I want to read data. And in case I lose 1 drive, I will lose all data also. I prefer individual FS BRTFS and joinning the disks with mergerfs.
About using BRTFS, I will just check how to run scrubs, and other basic info, not that many, as OMV, lets me mount and format BRTFS, and mergerfs has the plugin to join the FS. So apart from running scrubs on CLI, I can not thing about anything else right now.
You can do what you're describing above with MergerFS which logically combines disks. Adding SNAPRAID will give you checksum based bitrot protection at the cost of one disk as the parity drive. (The parity disk must be the largest.) With mergerfs, all that's needed is an understanding of the storage policy. SNAPRAID, on the other hand, requires a bit of reading to understand how it works.
You could do the same with BTRFS in a RAID5 equivalent, but BTRFS still has RAID5/6 issues. In either case, a bit of reading should be done to understand the implementation.
I've been testing BTRFS for bitrot correction performance. While my results are far from conclusive, I have some concerns. I plan to refine the test procedure and look a bit closer, over the winter months.
Well, I am not able to use Snapraid, as I do not want to use parity drive, as I wrote before, thats why I have the backup for. So I need a bitrot protection FS that will help me identifying is something gets corrupt or not.
At the same time, I want my data to be loadbalanced in disks, like if they were individual (NOT RADID0). So I found the option to create individual BRTFS Filesystems, and then join them with mergerfs. Any concerns about this?
But what I do not know still is the difference between mergerfs, and JBOD RAID, as they seem to be pretty the same.
Alles anzeigenJBOD is the default. Individual drives. sda, sdb, sdc and so on.
For instance an external USB enclosure for multiple drives might have a JBOD setting. Then the individual drives are available as individual drives. (Using one cable.)
By default you have separate drives. And can use them separately. Just a Bunch Of Drives. Call it JBOD if you want to.
Or you can use the separate drives together for software RAID. Pick a RAID level. Any RAID level.
Or you can use the separate drives together for mergerfs or Snapraid.
I checked JBOD RAID option, and it seems to join disks into 1 like mergerfs does, so still not now that much the difference between both. As if I am not wrong, if I break out, and split the disks, data will still remain there, and would be able to get accessed individually, right?
Just to point what I am trying to achieve.
It will be just to join 4 disks, that can work independently, but with the checksum protection option, to scrub the disk and locate any problem with my data.
This will end up, that in case I lose 1 disk, only data from that disk will be lost, which is not a problem for me, as I will use backups to restore it. And in case something flaps in my disk, I will do the same, restore the corrupted file from my backup.
Hello,
Thanks for the detailed explaination. At the moment I come from FreeNas, by using ZFS, and I can say I know more or less how do COW FS works, by their features, like dedup, snapshots, checksums, etc, etc.
The only thing I was asking was, about one of the RAID options I saw in OMV, that was the JBOD option. As I guess it is the same as what mergerfs does, which means "RAID0" but without splitting 1 file in all disks.
So thats why I was asking the pros and cons, about using mergerfs or JBOD OMV RAID option.
Kind regards
Hello guys,
Just a QQ, what is the difference between JBOD "raid" and using the plugin mergerfs that mounts on the filesystem?
I mean, I see that for things to work on OMV, I need first to decide if I want to use raid, in this case I can select JBOD, then select the FS, in this case, I was checking BTRFS, and then whats the point of getting MergeFS? Is not JBOD "raid" suppose to do the work?
I guess mergeFS is somehow most customizable, but apart from that, any other difference?
Kind regards
Hello,
Thanks for the reply. I was currently asking about OMV4 or OMV5, as I see that OMV5 was on beta, though I do not really know, if it went already out as stable, or it continues in beta.
Regarding btrfs, I asked as it seems it is the only filesystem, that will let me add or remove disks into my pool, without many issues, and at the same time, load balancing my data through my 4 disks, not like RAID.
Will search how to add btrfs into OMV, though if I remember correctly, there was an option in the gui, maybe as you say, just to format the disks, and then the rest needs to be done through CLI, which is a real pain to be honest.
Kind regards
Anyone else can provide some info about the new version of OMV and the questions I made?
Hello,
I already know about how ZFS works, as I come from freenas, and I think that doesn't meet my needs. Can you please explain me, why ZFS would be a good solution for the infrastructure I am searching?
Kind regards
Hello guys,
Coming from this discussion https://forum.openmediavault.o…?postID=224269#post224269 in which I was asking some questions about the file system to use.
But wanted to ask in here what do you think about it.
Just to recap:
I am trying to build my NAS and save all my media correctly inside of it. I was planning to use 4x12TB drives, without parity drive, but with offsite backup. I was trying to search for a filesystem that could protect me against bitrot, with data integrity protection.
I first thought about ext4, with snapraid and mergerfs, but it seems that snapraid scrub, will only work if I have a parity disk (which I don't).
The other alternative that I saw was using something like https://github.com/ambv/bitrot
And the last thing I found was about BTRFS, but I see people a year or 2 ago, was saying it was pretty new, and not that stable.
So wanted to ask in here, what do you think about BTRFS and new OMV version (is version 5 still in beta?), or if I need to stay with OMV version 4. Will this protect me for bitrot, and give me the good options of mergerfs as adding/removing disks as I want? Also, will I be able to only copy files into a disk? meaning that only 1 disk will be in use when ready a file and not the 4 of them.
Please let me know.
Kind regards
I will open another post regarding btrfs and new OMV version, to see what do people thing about and how stable it is.
Thanks for the help on here
Kind regards
Well, you told me about github.com/ambv/bitrot for bitrot protection on normal filesystems.
I was expecting to use that one, or maybe the one snapraid uses, but if I need parity drive for snapraid to use integrity protection, then, that will not work with me, as I am not willing to use a parity disk for my data. I prefer having only the backup, which is enough for me, at least for the non-important data I have.
In case of important data I will mount parity disk, but not for the no important one.
The only thing I am wondering is, if snapraid will work with 2 disks, making the sort of RAID1 I am searching for, but without being "on live" RAID.
Regarding for my "non important" data, apart from github.com/ambv/bitrot do you know any other system that can protect me, and give me integrity protection? Will btrfs work with OMV on its last version, with 4 disks and mergerfs?
I know about other FS for data integrity like ZFS, but what I really want is to be able to use mergerfs, so that I can add multiple disks in a future, without problems, and having the ability to scrub my data time to time.
BTW, do you know, if I can setup 4 individual ZFS filesystems for my 4 disks, and then merge them? I think that might give me, what I am searching for.
Kind regards
Hello,
Then in that case, I will check what type of file is, if is it important or not, and in case it is, I will just restore that file from my backup that is offsite.
Up to what I read, you were doing the same with your backups, don't you?
Kind regards
Hello,
I finally tried with snapraid for the checsumming stuff, and got this when tried to run it:
Self test...
No 'parity' specification in '/etc/snapraid.conf'
Am I not able to run just 4 disks without a parity drive? I just want snapraid for checksumming, nothing else.
Please let me know.
Kind regards
