btrfs makes old hdds appear to operate faster

[grahammechanical]

I tried again to get a Raring install on btrfs (yesterday's daily) Same result even though I choose to continue without installing a bootloader. I get an installer crashed message at the end and sudo update-grub from another Ubuntu does not detect an OS in the partition.

Is this because the format is btrfs? Or is it a problem with this particular daily? Will this happen on Ext4?

Update: This daily image installs without any problems when the file system is Ext4, including installing Grub into the MBR. I have just done it. So, it is an issue between Grub and the btrfs file system.

Regards.

[The Cog]

I just abandoned btrfs a couple of weeks ago. It had been getting slower and slower (all the firefox sqlite tables and cached images I suspect) and so I tried a defrag. Since you can only defrag one file at a time, I did something like:
find /home - exec btrfs defrag '{}' \;
When I came back after dinner, the PC had shut down (desktop, not on batteries) and the partition would not mount - invalid superblock etc.
So I restored a backup to jfs and now it feels like a new machine, much faster.

Did you attempt to do the rollback proceedure while you were experimenting with it?

No. This was on a separate /home partition. Although / was also on btrfs, I never tried to defrag it. I'm sure I rolled back a root partiton apt-get intsall once though. It's the defrag that scuppered me.

[jerrylamos]

No. This was on a separate /home partition. Although / was also on btrfs, I never tried to defrag it. I'm sure I rolled back a root partiton apt-get intsall once though. It's the defrag that scuppered me.

We defrag on Microsoft XP wjocj actually seems to do something, however the result is not what you'd expect. XP allocates files by the "scatter" method all over the disk with gaps in between, which causes a lot of grief trying to push it down to resize.

Booting Windows 7 first thing I did after seeing it worked was to boot Ubuntu live and resize to make space for Linux. Did not want to run Windows 7 hardly any so Windows 7 wouldn't allocate files here and there and everywhere.

Never had to defrag Ubuntu and haven't noticed the need, even when I do some resizes.

[castrojo]

Attempting to rollback to quantal was an absolute and complete failure. All I have now is the Grub Rescue menu Thats what you get when you forget to :
sudo update grub

Did it only fail because of not upgrading grub or did the entire thing blow up? So basically if we remember to update grub then it will work?

[grahammechanical]

An update to my attempts to use btrfs.

I tried installing 12.10 on a btrfs partition. Same problem of not being able to install grub into MBR /dev/sda. This time I told it to install grub into a partition (sda9 which 12.10 was being installed on). Result = Grub rescue - unknown file system and without a Grub menu at all. Options:

1) Press Esc to bring up the Grub menu. Failed. Still Grub rescue.
2) Get some experience using Ubuntu Secure Remix - Boot Repair utility.
3) Simply re-install Ubuntu into that btrfs partition but as Ext4.

I tried using Boot Repair. What a brilliant utility! It got me booting into my standby 12.04 on sda1. Did not pick up the other Ubuntus but update-grub has fixed that.

I am coming to the conclusion that the problem is with Grub and btrfs. On reflection and from an uneducated persons view point, I think that os-prober cannot read btrfs formatted partitions. All the folders and files seem to be on the partition but os-prober when run from Ubuntu on another partition does not detect the Ubuntu on the btrfs partition.

Regards.

[scradock]

An update to my attempts to use btrfs.

...

I am coming to the conclusion that the problem is with Grub and btrfs. On reflection and from an uneducated persons view point, I think that os-prober cannot read btrfs formatted partitions. All the folders and files seem to be on the partition but os-prober when run from Ubuntu on another partition does not detect the Ubuntu on the btrfs partition.

Regards.

I concur. I have a perfectly sound install of 12.04 on a btrfs partition, but os-prober never sees it from another Ubuntu install. I have simply added the relevant grub menu entries using /etc/grub.d/40_custom, and it boots fine.

[grahammechanical]

I have simply added the relevant grub menu entries using /etc/grub.d/40_custom, and it boots fine.

I cannot do this as I installed 12.10 on Ext4 over that btrfs partition. I had to do that because the boot process was more messed up than I thought. Boot Repair got me into 12.04 on sda1 but after clicking Restart the machine went into a loop = reboot - flash of purple - reboot.

An new install of something was the only way to straighten things out. I did give this new 12.10 install its own btrfs /home partition. So, that is something.

I am thinking that the solution would be to have a small /boot partition formatted as Ext4, Ext3 or even FAT32. I think that Ubuntu will run on btrfs but Grub cannot read the boot configuration file if it is on btrfs.

I am not sure that I want to do this experiment as I would then have sda11 before sda1. And that is not logical.

Regards.

[oldfred]

We have seen os-prober not see other types like LVM. On default Fedora installs you have to install the lvm2 driver and mount the Fedora partition. Then os-prober finds the Fedora.

It may be because grub2 now has all the add in modules to load drivers for just about everything. But if module is not loaded or it does not know to auto load it then it does not work?

[ventrical]

Did it only fail because of not upgrading grub or did the entire thing blow up? So basically if we remember to update grub then it will work?

Good question casrojo.

Please allow me to rephrase my most recent comment. I *assumed* that it was not updating Grub which caused the fail. I see it now that this is highly unlikely. I then assume that there would have to be a sort of weaving method with the sources.list.

I think the actual snapshot (of original quantal) is still on the drive but I am only getting
grub rescue > prompt.

I tried to repair it with SuperGrub rescue but that failed.

[ventrical]

Ok..yes .. the snapshot is still on the drive. I used a Quantal 'live' USB and nautilus shows it there.

@ is the snapshot ..but it beats me how to load it at bootup. No terminal .. just Grub Rescue>

And further more I have no idea what happened to the 'upgraded' raring ringtail!