Earlier on, today, I decided to stress-test the “ZFS on Linux” project’s drivers under my Ubuntu VirtualBox VM, by creating a new ZPool spanning two virtual SATA hard disks, and trying to extract a Wireshark SVN source archive within it.
However, after my initial attempt at extracting the archive seemingly stalled, and discovering that the kernel logs were full of “vmap allocation for size 4198400 failed: use vmalloc=<size> to increase size” errors, I ended up reading a page on the MythTV Wiki detailing a similar problem.
Unfortunately, the suggestions provided there weren’t entirely up-to-date with the configuration of GRUB in that version of Ubuntu – although they provided some useful recommendations for identifying a remedy for this issue.
Finally, after searching for “3.0.0-14-generic” within “/boot/grub/grub.cfg”, appending “vmalloc=400M” to the line beginning with “linux /boot/vmlinuz-3.0.0-14-generic“, and rebooting the VM, I was able to successfully unpack the archive, and build the software itself.
Obviously, this is just a temporary method that will probably get broken when upgrading the GRUB, or Linux kernel versions – but I thought that I’d quickly share this workaround, for future reference.