On Thu, 19 Jun 2014, Greg Troxel wrote:
Gerard Lally <lists+netbsd.users%netmail.ie@localhost> writes:1) Is it safe to use GPT on NetBSD? The warnings on the gpt man page leave me less than 100% confident.On NetBSD 6, I would say yes. Even on 5, I think so. I am not really clear on booting from GPT, but for other than the boot/root fs it should be fine. I have multiple systems with gpt disks and no issues.
I have used it on -5 for a long time. I have also got GPT booting working on -5 by compiling the -6 gpt sources on -5 (with minimal hacking). The trick is not to read the man pages, then you won't know it's not supposed to work :-)
backup1# uname -r
5.1_STABLE
backup1# gpt show ld0
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 30
64 20971520 1 GPT part - NetBSD UFS/UFS2
20971584 8388608 2 GPT part - NetBSD swap
29360192 9736507256 3 GPT part - NetBSD UFS/UFS2
9765867448 39
9765867487 32 Sec GPT table
9765867519 1 Sec GPT header
backup1# df
Filesystem 1K-blocks Used Avail %Cap Mounted on
/dev/dk0 10323036 4293292 5513596 43% /
tmpfs 1424 348 1076 24% /dev
/dev/dk2 4792839924 2848287660 1704910268 62% /backup
kernfs 1 1 0 100% /kern
ptyfs 1 1 0 100% /dev/pts
procfs 4 4 0 100% /proc
2) As I understand it the NetBSD FFS filesystem is capable of growing to 8 zettabytes, but MBR partitioning combined with traditional disklabels meant we were restricted to 2 (or 4) TB partitions in practice. Am I right in saying that GPT and wedges remove this restriction, and we can now create partitions and filesystems greater than 4TB?I think disklabels are limited to 2TB; I'm not sure if it's the whole disk or per partition. (Maybe that's 4TB.) That is correct - GPT does not have a 2TB limit.
See above. The thing I find annoying is that wedges/gpt partitions cannot be resized. For this reason, when I move the relevant machines to -6 I'll use lvm.
-- Stephen