btrfs on 12 tb drive takes to long to precheck and fails to mount in fstab

how can we find the replys to anything we post in this forum. i imagine everyone is asking same questions over and over and over because they cannot ever see there replys. I do not see a option to list my posts or replys and searching for myself is just a pain with those questions every time.

Btrfs formated on a 12 terrabyte segate drive. I have it set to mount in fstab but it never does. the smaller drives of 2 and 4 tb mount ok. i have to manualy mount the 12 tb every time.

Click on “My Profile”. I see that toward the top right of the browser page.

On the next screen, you should see links for “Find latest posts” and “Find latest started threads”.

I see this is your first post here. Welcome to these forums.

That sais I must admit that most of us are not clairvoyant. Thus please do not just say tou have an entry in /etc/fstab, but please show it. And when you have problems mounting it, just do that mount and show us what the results are.

That showing is best done using CODE tags. This is what we tell most newcomers:

There is an important, but not easy to find feature on the forums.

Please in the future use CODE tags around copied/pasted computer text in a post. It is the # button in the tool bar of the post editor. When applicable copy/paste complete, that is including the prompt, the command, the output and the next prompt.

UUID=xxxxxxxxxxxxxxxxxxxxxxxxx /mnt/disk21 btrfs nosuid,nodev,nofail 0 0

it seems to take over a minute to mount this drive and fstab does not seem to like that.

There is no need to quote your own first post. We can all read and know what you were asking. Quoting is more for showing which (part of) a post you are answering to.

I tried to explain how to post your computer facts in your posts using copy/paste and the CODE tags. People here realy like it to see exactly what you saw and xxxxxxxxxxxxxx is NOT what you saw. An example of how to post a /etc/fstab:

henk@boven:~> cat /etc/fstab/dev/disk/by-id/ata-Hitachi_HDT725032VLA380_VFJ201R23XUEXW-part2 /                    ext4       acl,user_xattr        1 1
/dev/disk/by-id/ata-Hitachi_HDT725032VLA380_VFJ201R23XUEXW-part1 swap                 swap       defaults              0 0
/dev/disk/by-id/ata-Hitachi_HDT725032VLA380_VFJ201R23XUEXW-part3 /home                ext4       defaults              1 2
#/dev/disk/by-id/ata-Hitachi_HDT725032VLA380_VFJ201R23XUEXW-part5 /mnt/B               ext4       ro,acl                1 2
#/dev/disk/by-id/ata-Hitachi_HDT725032VLA380_VFJ201R23XUEXW-part6 /mnt/B/home          ext4       ro,acl                1 2

As you mount by UUID, can you please also show

ls -l /dev/disk/by-uuid

so we can find out what the device is.

/etc/fstab is just a configuration file it does not do anything by itself, thus it can not “like something”.

I do not quite understand why you choose for this large disk (or what you mount) to use Btrfs. Apparently it is not your / file system and I do not have seen many arguments to use it for other file systems (for /home e.g. zfs seems to be recommended). Are you using snapshots on it?

Maybe look at logging (dmesg) while mouting it to see if there is anything going on.
You could also umount it “manualy” and then mount it again “manualy” to see if there are any messages displayed by mount.

Although frankly speaking this post looks more like a rant …

btrfs has known scalability issue that results in increased mount time as file system grows. Output of “btrsf filesystem usage” could be helpful in estimating how probable this issue is in this case.

Still filesystem needs to be large - really large - to exceed default 90 seconds timeout; I would not really expect it on 12TB. The only way to confirm it is to gather kernel execution statistic during mount.

See as example

the 12 tb is near full and it seems to take over 90 seconds to precheck. I read there is another way to mount drives besides using fstab so I am looking into that. I have been testing this on debian and have installed suse on a second ssd as soon as i finish backing up the drives im going to switch to suse and see it it has the same problem with the 12 tb drive.

Does anyone have a good knowledge of raid 1 on btrfs? I would like to know if i make a 10 drive raid 1 and then how complicated it would be to split all the 10 drives back into single drives maintaining the directory structure on each drive. I use mergerfs to join drives now and like to be able to remove drives as needed. Can btrfs do this also in raid 1 ? I am in process of building an extra 10 drive raid 1 box so i can test this, I cannot seem to find any factual information on this online.

Start new thread for new question.

There is a post above with five (5) points. You did not take the trouble to answer even one of them (not even by saying you do not want to give an answer or asking for clarification bdecause you did noty understand what was said). This is a perfect way to loose any further interest in your thread from people. So please re-think about this.

And yes, one subject per thread.

I believe I found why the 12 tb drive was so slow loading. I had it connected to a sata 2 controller instead of sata 3 and sata 2 is much slower. the drive was nearly full so it was taking a long time to load.

I just received some sata 3 multiplexers that handle 5 drives each and am installing them and replacing the sata 2 multiplexers. I hope this resolves this.

Even on the sata 3 controler the drive will not mount fast enough and fails in fstab. it will only mount manually. If anyone else trys these 12 tb drives just be warned they mounts for them are differnt than other sata drives there are only 2 holes to mount them into a box and they are the far ends of the drive the center hole no longer exists.

I am going to have to remove this drive from my main array of drives as it does not mount reliably. I hope as more people use them someone finds a solution.

ok i’m pulling this drive out of my system the Seagate 12 terabyte drive ST12000VN0007 does not seem reliable enough I have had 2 errors just copying folders. If you try these drives make sure you have raid or some condoms to keep the bugs out.

ok i’m pulling this drive out of my system the Seagate 12 terabyte drive ST12000VN0007 does not seem reliable enough I have had 2 errors just copying folders. If you try these drives make sure you have raid or some condoms to keep the bugs out.

I did manage to get 18 drives to work ok on btrfs from 2 to 6 tb it was only the 12 tb drive that was having problems.