4 ms·

OpenBSD has had FFS2 since 4.2 in Nov 2007. FFS2 doesn't have any functional partition size limitations.

by dmm 14y ago

papsosouid 14y ago
Don't you still have to fsck those FFS2 partitions though? That becomes a real problem with very large filesystems. I have been out of the loop for like 7 years now, but I didn't think openbsd offered background fsck or journalling?
- protomyth 14y ago
  from: http://www.openbsd.org/faq/faq14.html#LargeDrive http://www.openbsd.org/faq/faq14.html#LargeDrive --------------------------------------------- FFS vs. FFS2 Using FFS, OpenBSD supports an individual file system of up to 231-1, or 2,147,483,647 blocks, and as each block is 512 bytes, that's a tiny amount less than 1T. FFS2 is capable of much larger file systems, though other limits will be reached long before the file system limits will be reached. The boot/installation kernels only support FFS, not FFS2, so key system partitions (/, /usr, /var, /tmp) should not be FFS2, or severe maintenance problems can arise (there should be no reason for those partitions to be that large, anyway). For this reason, very large partitions should only be used for "non-system" partitions, for example, /home, /var/www/, /bigarray, etc. Note that not all controllers and drivers support large disks. For example, ami(4) has a limit of 2TB per logical volume. Always be aware of what was available when a controler or interface was manufactured, and don't just rely on "the connectors fit". Larger than 2TB disks The MBR system used on PCs only directly understands disks up to 2TB in size. fdisk(8) will typically report a disk size of the real size modulo 2TB, so your 2.7TB disk (sold as 3TB) will show as around 700GB in fdisk(8). This does not in any way hinder OpenBSD's ability to utilize larger disks, as the MBR is used only to bootstrap the OS, once the OS is running, the file systems are defined by the disklabel, which does not have a 2TB limit. To use a larger than 2TB disk, create an OpenBSD partition on the disk using fdisk, whatever size fdisk will let you. When you label the disk with disklabel(8), use the "b" option to set the OpenBSD boundaries (which defaulted to the size of the OpenBSD fdisk partition) to cover the entire disk. Now you can create your partitions as you wish. You must still respect the abilities of your BIOS, which will have the limitation of only understanding fdisk partitions, so your 'a' partition should be entirely within the fdisk-managed part of the disk, in addition to any BIOS limitations. --------------------------------------------- ZFS on FreeBSD was just a bit easier (for me) for our Samba PDC. Otherwise, I use OpenBSD.
- dmm 14y ago
  Yes, you still have fsck them. It sucks.
- 4ad 14y ago
  Unfortunately not. The file system is the achilles' heel IMO.
jnazario 14y ago
i think the comment is about the archaic interface to the disk partitioning that openbsd uses in the installer. it confuses a lot of people. (former openbsd user, committer, and book author. no, i don't use it any more.)
- protomyth 14y ago
  the tool is a bit of a pain, but they have an autogen now. It really doesn't take me long, but it is a might bit confusing for new people.
  - danielweber 14y ago
    That's awesome. I'd been using a script that emitted all the "right answers" that I would then paste into the installer, mostly because of that.
- gnu8 14y ago
  I still don't understand this criticism of OpenBSD. I managed to use the installer to set up a fully partitioned OpenBSD system circa version 2.7 as a stoned highschool freshman. I think some people just have trouble using computer programs that require them to use a keyboard and read the documentation.
  - jnazario 14y ago
    maybe. took me a few minutes but honestly it got in a number of peoples' ways the first time they saw openbsd's installed way back in the day, and they were no dummies. this is ~1999 mind you, i have no idea since about 2004 what openbsd has been like to install.
- meaty 14y ago
  Seriously it's not that hard.
  - protomyth 14y ago
    True, it really isn't. It is just different and a little weird with commands like 'a a'. After the first time you know all the letters and what partitions to lay down.

OpenBSD has had FFS2 since 4.2 in Nov 2007. FFS2 doesn't have any functional partition size limitations.

by dmm 14y ago

OpenBSD has had FFS2 since 4.2 in Nov 2007. FFS2 doesn't have any functional partition size limitations.

Don't you still have to fsck those FFS2 partitions though? That becomes a real problem with very large filesystems. I have been out of the loop for like 7 years now, but I didn't think openbsd offered background fsck or journalling?

protomyth 14y ago
from: http://www.openbsd.org/faq/faq14.html#LargeDrive http://www.openbsd.org/faq/faq14.html#LargeDrive --------------------------------------------- FFS vs. FFS2 Using FFS, OpenBSD supports an individual file system of up to 231-1, or 2,147,483,647 blocks, and as each block is 512 bytes, that's a tiny amount less than 1T. FFS2 is capable of much larger file systems, though other limits will be reached long before the file system limits will be reached. The boot/installation kernels only support FFS, not FFS2, so key system partitions (/, /usr, /var, /tmp) should not be FFS2, or severe maintenance problems can arise (there should be no reason for those partitions to be that large, anyway). For this reason, very large partitions should only be used for "non-system" partitions, for example, /home, /var/www/, /bigarray, etc. Note that not all controllers and drivers support large disks. For example, ami(4) has a limit of 2TB per logical volume. Always be aware of what was available when a controler or interface was manufactured, and don't just rely on "the connectors fit". Larger than 2TB disks The MBR system used on PCs only directly understands disks up to 2TB in size. fdisk(8) will typically report a disk size of the real size modulo 2TB, so your 2.7TB disk (sold as 3TB) will show as around 700GB in fdisk(8). This does not in any way hinder OpenBSD's ability to utilize larger disks, as the MBR is used only to bootstrap the OS, once the OS is running, the file systems are defined by the disklabel, which does not have a 2TB limit. To use a larger than 2TB disk, create an OpenBSD partition on the disk using fdisk, whatever size fdisk will let you. When you label the disk with disklabel(8), use the "b" option to set the OpenBSD boundaries (which defaulted to the size of the OpenBSD fdisk partition) to cover the entire disk. Now you can create your partitions as you wish. You must still respect the abilities of your BIOS, which will have the limitation of only understanding fdisk partitions, so your 'a' partition should be entirely within the fdisk-managed part of the disk, in addition to any BIOS limitations. --------------------------------------------- ZFS on FreeBSD was just a bit easier (for me) for our Samba PDC. Otherwise, I use OpenBSD.
dmm 14y ago
Yes, you still have fsck them. It sucks.
4ad 14y ago
Unfortunately not. The file system is the achilles' heel IMO.

jnazario 14y ago

i think the comment is about the archaic interface to the disk partitioning that openbsd uses in the installer. it confuses a lot of people. (former openbsd user, committer, and book author. no, i don't use it any more.)

protomyth 14y ago
the tool is a bit of a pain, but they have an autogen now. It really doesn't take me long, but it is a might bit confusing for new people.
- danielweber 14y ago
  That's awesome. I'd been using a script that emitted all the "right answers" that I would then paste into the installer, mostly because of that.
gnu8 14y ago
I still don't understand this criticism of OpenBSD. I managed to use the installer to set up a fully partitioned OpenBSD system circa version 2.7 as a stoned highschool freshman. I think some people just have trouble using computer programs that require them to use a keyboard and read the documentation.
- jnazario 14y ago
  maybe. took me a few minutes but honestly it got in a number of peoples' ways the first time they saw openbsd's installed way back in the day, and they were no dummies. this is ~1999 mind you, i have no idea since about 2004 what openbsd has been like to install.
meaty 14y ago
Seriously it's not that hard.
- protomyth 14y ago
  True, it really isn't. It is just different and a little weird with commands like 'a a'. After the first time you know all the letters and what partitions to lay down.