ubuntu 8.04 wont use gpt for 2tb+ devices

[_max_]

Binary package hint: ubiquity

In both the Ubuntu 8.04 BETA regular and alternate cd there is no way to switch to GPT label.
since msdos label can only handle 2tb partitions my remaining 3tb are left useless, i tried tricking the system by changing label in console, however parition tables are commited after pressing the final [install]
if i boot alternate cd there is no parted, and no option to change label at all.

im using a 3ware 9500s-12 card with 6x1000gb samsung discs, linux detects it fine as /dev/sda and 5000GB. So does the installer, it just simply doesn't switch to gpt. and i dont see any reason for using msdos as "default" in any case since drives are growing cheeper and larger by the minute.

[Colin Watson (cjwatson)]

There is no "reason", because it is already supposed to use GPT as default in this case - so we need to track down why this isn't working.

[Colin Watson (cjwatson)]

I tried reproducing this by making a one-character change to the relevant code to trigger on 2GB rather than 2TB so that I could try it with the disk space I have available. When I did that, it switched to GPT as expected. The only thing I can think of that this might be is a 64-bit arithmetic problem, but I've had no luck reproducing that with unit tests of chunks of the relevant code, so I'll need the logs I asked for (syslog and partman) to get any further here.

[AJ (akertis)]

I ran into the same problem with the beta releases. I have tried to make a gpt label with parted and after I install it is back to a msdos label. Does ubuntu use gpt by default or does it decide on how big the disk is being used?

[Colin Watson (cjwatson)]

AJ, I need those logs in order to investigate this: /var/log/syslog and /var/log/partman. You can extract them by going back to the installer main menu and selecting "Save debug logs", or, if you've completed an installation, you'll find them in /var/log/installer/. I haven't been able to reproduce this in my (necessarily limited and out-of-context) tests.

Note that you MUST NOT run parted to create a disk label manually while the installer's partitioner is running. It keeps its own state of what's on the disk, and you WILL confuse it if you run parted manually at the same time. It's not clear to me whether either you or _max_ did that.

Ubuntu offers GPT as a disk label creation choice in expert mode. Aside from that, it uses GPT when the disk size exceeds 2TB. This shouldn't affect what it does with existing disk labels, where it should use the current label type rather than creating a new one.

[Charlie Kravetz (cjkgeek)]

We are closing this bug report because it lacks the information we need to investigate the problem, as described in the previous comments. Please reopen it if you can give us the missing information, and don't hesitate to submit bug reports in the future. To reopen the bug report you can click on the current status, under the Status column, and change the Status back to "New". Thanks again!