More More BTRFS fun Multibooting to subvolumes on the same partition.

[steve7233]

The thread was closed. I made a new one so I could tell Vinny and all the good news. Now the answer to Vinny's #8 post on the last thread for this subject is yes you can now convert an old ext4 or any other to BTRFS without having to recreate the data! I am to new to BTRFS and don't understand all of it but it looks like you use the convert command to convert FS types.

Thread title contains prohibited characters I copied and pasted the old threads name.
edit: It was the colon in the title. Apparently, someone decided to make the colon illegal eventho the old thread used it in the title.

[oshunluvr]

The ext convert tool has not been updated/validated in quite a while. The btrfs team would advise using caution if attempting a conversion.

The conversion tool has one other caveat - it only does a root level conversion. Meaning, it leaves your files in the parent container of the btrfs filesystem. Most of the benefits of btrfs come from the use of subvolumes. Since you would have to manually move the files to a subvolume anyway, IMO the far better method is to just create a btrfs filesystem and move the files into a subvolume there. Then, after validation of it working properly, delete the ext4 file system.

and yes, the colon is restricted from thread titles along with some other characters. They could possibly used as attack vectors - don't ask me to explain how.

[Snowhog]

and yes, the colon is restricted from thread titles along with some other characters. They could possibly used as attack vectors - don't ask me to explain how.

The use of a custom vBulletin MOD to identify prohibited characters in Thread Titles was instituted because of a function within ZB Block — the software that protects KFN from ‘the bad guys’ — was being triggered when certain actions from within the Forum were executed, and, when certain Administrative actions were taken from within the AdminCP.

It is sometimes a fine line between being protected by, and falsely triggering, ZB Block. I monitor that line closely. Ensuring that KFN is adequately protected is a priority, and since we’ve been using ZB Block, very, very few unsavory types have been able to get in.

[oshunluvr]

very, very few unsavory types have been able to get in.

Well, I can name a few ROFL...

...present company excepted, of course

[vinnywright]

The thread was closed. I made a new one so I could tell Vinny and all the good news. Now the answer to Vinny's #8 post on the last thread for this subject is yes you can now convert an old ext4 or any other to BTRFS without having to recreate the data! I am to new to BTRFS and don't understand all of it but it looks like you use the convert command to convert FS types.

Thread title contains prohibited characters I copied and pasted the old threads name.
edit: It was the colon in the title. Apparently, someone decided to make the colon illegal eventho the old thread used it in the title.

this is post #8 ,,,and not me .

https://www.kubuntuforums.net/showth...l=1#post404679

if this is the thread you are talking about ,,,?

and I dont think I would have asked about the convert tool ,,,as it was the first BTRFS tool I used ,,,,,I already new about it ...hear>>>>>>>>>

https://www.kubuntuforums.net/showth...l=1#post365935

VINNY

[GreyGeek]

[#]btrfs[/#]

[steve7233]

@ oshunluvr, I tried doing what you said in your post about multi booting using BTRFS -unfortunately somebody closed the thread so I can't post any questions like you asked if anyone had trouble getting it to work. It seemed to work as I could boot and I ran update-grub and it saw the subvolumes and I saw the name of my new subvolume to be booted. When I went to install Lbuntu 14.04, the installer said there were no visible installs. I quit of course and rebooted Kubuntu and came here. Could I have missed something in grub config or what?

[oshunluvr]

No, you didn't miss anything. I need to do a write-up on this:

os-prober - the tool that GRUB uses to detect installs - does not look inside subvolumes to detect other installs. I doubt it ever will. My untested belief is, if you mounted each install first, then run os-prober, it might find them. Even if it did, it would be useless to you because they grub.cfg would have the mounts in it's menu - which wouldn't exist on the next reboot.

Rest assured, as long as you don't select "Format this partition" during installation AND you have previously renamed the subvolumes from @ and @home to something else, they will still be there after the second (and beyond) installs to the same btrfs volume.

Here's the write up on how to do this: https://www.kubuntuforums.net/showth...241#post405241