GUID Partition Table • Unified Extensible Firmware Interface (UEFI) • GUID Partition Table (GPT) • gpart(8) • Root On ZFS • FreeBSD9 – bsdinstall • Soft-Update Journaling (SU+J) Computer Center, CS, NCTU CS, Computer Center, Unified Extensible Firmware Interface BIOS limitations • 16-bit processor mode • 1MB addressable space UEFI advantages • UEFI v2.3.1 in April 2011 • Disk device compatibility (GUID Partition Table) • Processor compatibility (x86, x64, ARM) 2 Computer Center, CS, NCTU CS, Computer Center, GUID Partition Table – (1) Limitation of MBR partition table • Partition record active(1)、first CHS(3)、type(1)、last CHS(3)、start LBA(4)、size(4) • Maximum capacity (232-1) x 512 bytes ~ 241 bytes = 2TBytes GPT • Maximum capacity: 8ZBytes (273 bytes) • Used on some BIOS system 3 Computer Center, CS, NCTU CS, Computer Center, GUID Partition Table – (2) GPT • LBA 0: Legacy MBR • LBA 1: GPT Header • LBA 2~33: Partition Entries 128 partitions • LBA 34~: Partitions • LBA -34 ~ -1: Secondary GPT data Misaligned block • SSD (1K LBA) • WD (4K sector) 4 Computer Center, CS, NCTU CS, Computer Center, GUID Partition Table – (3) Legacy MBR (LBA 0) • A single partition of type 0xEE, and of whole disk size (max 2T) • For OSes which cannot read GPT: unknown partition, no space • For GPT-aware OSes: check the “protective MBR” 5 Computer Center, CS, NCTU CS, Computer Center, GUID Partition Table – (4) Partition header table (LBA 1) Offset Length Contents 0 8 bytes Signature ("EFI PART", 45 46 49 20 50 41 52 54) Revision (For GPT version 1.0 (through at least UEFI version 2.3.1), the value is 8 4 bytes 00 00 01 00) 12 4 bytes Header size in little endian (in bytes, usually 5C 00 00 00 meaning 92 bytes) 16 4 bytes CRC32 of header (0 to header size), with this field zeroed during calculation 20 4 bytes Reserved; must be zero 24 8 bytes Current LBA (location of this header copy) 32 8 bytes Backup LBA (location of the other header copy) 40 8 bytes First usable LBA for partitions (primary partition table last LBA + 1) 48 8 bytes Last usable LBA (secondary partition table first LBA - 1) 56 16 bytes Disk GUID (also referred as UUID on UNIXes) 72 8 bytes Partition entries starting LBA (always 2 in primary copy) 80 4 bytes Number of partition entries 84 4 bytes Size of a partition entry (usually 128) 88 4 bytes CRC32 of partition array 92 * Reserved; must be zeroes for the rest of the block (420 bytes for a 512-byte LBA) 6 Computer Center, CS, NCTU CS, Computer Center, GUID Partition Table – (5) Partition header table (LBA 1) # dd if=/dev/ada0 bs=512 count=1 skip=1 | hd 00000000 45 46 49 20 50 41 52 54 00 00 01 00 5c 00 00 00 |EFI PART....\...| 00000010 e6 f0 27 96 00 00 00 00 01 00 00 00 00 00 00 00 |..'.............| 00000020 2f 60 38 3a 00 00 00 00 22 00 00 00 00 00 00 00 |/`8:....".......| 00000030 0e 60 38 3a 00 00 00 00 7f a3 90 90 46 b4 de 11 |.`8:........F...| 00000040 8e b8 00 21 85 12 22 74 02 00 00 00 00 00 00 00 |...!.."t........| 00000050 80 00 00 00 80 00 00 00 e0 9d 1a 52 00 00 00 00 |...........R....| 00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| * 00000200 7 Computer Center, CS, NCTU CS, Computer Center, GUID Partition Table – (6) Partition entries (LBA 2~33) • 128 bytes for each partition entry Offset Length Contents 0 16 bytes Partition type GUID 16 16 bytes Unique partition GUID 32 8 bytes First LBA (little-endian) 40 8 bytes Last LBA (inclusive, usually odd) 48 8 bytes Attribute flags (e.g. bit 60 denotes read-only) 56 72 bytes Partition name (36 UTF-16LE code units) 128 Total 8 Computer Center, CS, NCTU CS, Computer Center, GUID Partition Table – (7) Partition type GUID freebsd-boot 83BD6B9D-7F41-11DC-BE0B-001560B84F0F freebsd 516E7CB4-6ECF-11D6-8FF8-00022D09712B freebsd-swap 516E7CB5-6ECF-11D6-8FF8-00022D09712B freebsd-ufs 516E7CB6-6ECF-11D6-8FF8-00022D09712B freebsd-vinum 516E7CB8-6ECF-11D6-8FF8-00022D09712B freebsd-zfs 516E7CBA-6ECF-11D6-8FF8-00022D09712B 9 Computer Center, CS, NCTU CS, Computer Center, FreeBSD – gpart (1) gpart(8) • Control utility for the disk partitioning GEOM class (ad0) GEOM_PART_MBR (ad0 ad0s1) – GEOM_PART_BSD (ad0s1 ad0s1a) GEOM_PART_GPT (ad0 ad0p1) • gpart create -s mbr ad0 gpart add -t freebsd ad0 (ad0 ad0s1) gpart create -s bsd ad0s1 • gpart create -s gpt ad0 • gpart destroy [ -F ] ad0 -F: forced destroying of the partition table 10 Computer Center, CS, NCTU CS, Computer Center, FreeBSD – gpart (2) gpart(8) • gpart add -t type [ … ] ad0 type: freebsd-boot, freebsd-swap, freebsd-ufs, freebsd-zfs, freebsd -b start -s size -a alignment: -a 4k for 4K-sector HDD -i index -l label: used on partitioning schemes that support partition labels • gpart delete –i index ad0 • gpart show [ -l | -r ] [ -p ] ad0 -l: print partition labels instead of partition type -r: show GUID -p: show provider names instead of partition indexes 11 Computer Center, CS, NCTU CS, Computer Center, FreeBSD – gpart (3) gpart(8) • gpart bootcode [ -b bootcode ] [ -p partcode -i index ] ad0 -b: embed bootstrap code into the partitioning scheme’s metadata -p: write bootstrap code into a partition Bootstraping for MBR scheme – /boot/mbr or /boot/boot0 in partition table’s metadata » /boot/mbr searches partition with active attribute » /boot/boot0 has a boot manager – /boot/boot in BSD partition table’s metadata Bootstraping for GPT scheme – /boot/pmbr in the first disk sector (Protective MBR) » /boot/pmbr searches the freebsd-boot partition – /boot/gptboot or /boot/gptzfsboot in freebsd-boot partition » /boot/gptboot searches the freebsd-ufs partition to run /boot/loader » /boot/gptzfsboot searches the freebsd-zfs partition to run /boot/zfsloader 12 Computer Center, CS, NCTU CS, Computer Center, FreeBSD – gpart (4) gpart(8) • gpart modify -i index [ -l label ] [ -t type ] ad0 • gpart resize -i index [ -a alignment ] [ -s size ] ad0 • gpart { set | unset } -a attrib -i index ad0 Set "Active" for MBR scheme – gpart set -a active –i 1 ad0 • gpart { backup | restore } ad0 • gpart recover ad0 GPT-only • gpart { command … -f x | commit | undo } ad0 13 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (1) Root On ZFS • Using MBR disk UFS /boot FreeBSD-ZFS partition in a FreeBSD MBR slice – dd if=/mnt2/boot/zfsboot of=/dev/ad0s3 count=1 – dd if=/mnt2/boot/zfsboot of=/dev/ad0s3a skip=1 seek=1024 FreeBSD MBR slice – Fails to boot • Using GPT disk Disadvantage – Can’t dual boot using FreeBSD commercial bootcode – Using GPT-aware grub setup and hybrid GPT/MBR http://wiki.freebsd.org/RootOnZFS now for 8.x • 9.0 http://www.aisecure.net/2011/05/01/root-on-zfs-freebsd-current/ 14 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (2) Creating a bootable ZFS Filesystem • Create GPT disk gpart create -s gpt ad0 • Create the boot, swap and zfs partitions gpart add -s 64k -t freebsd-boot ad0 gpart add -s 4g -t freebsd-swap -l swap0 ad0 gpart add -t freebsd-zfs -l disk0 ad0 • Install the Protected MBR (pmbr) and gptzfsboot loader gpart bootcode -b pmbr -p gptzfsboot -i 1 ad0 • Load ZFS kernel module kldload zfs • Create ZFS Pool zroot zpool create zroot /dev/gpt/disk0 zpool set bootfs=zroot zroot 15 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (3) Installing FreeBSD to the ZFS filesystem • Create ZFS filesystem hierarchy 16 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (4) Installing FreeBSD to the ZFS filesystem • Install FreeBSD to zroot Manually install base, kernel(s), lib32, games, doc, … • Make /var/empty readonly zfs set readonly=on zroot/var/empty • Manually configure chroot /etc/rc.conf – hostname, networks, zfs_enable, sshd, ntpd, … /boot/loader.conf – zfs_load, vfs.root.mountfrom root password Time zone … 17 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (5) Installing FreeBSD to the ZFS filesystem • Install zpool.cache to the ZFS filesystem zpool export zroot zpool import –o cachefile=/tmp/zpool.cache zroot Copy /tmp/zpool.cache into zroot/boot/zfs/ Finish install • Create /etc/fstab swap • Set mount points for zfs filesystems zfs set mountpoint=blah zroot/blah Alternatively, you can specify these in /etc/fstab 18 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (6) gpart show # gpart show => 34 83886013 ada0 GPT (40G) 34 128 1 freebsd-boot (64k) 162 4194304 2 freebsd-swap (2.0G) 4194466 79691581 3 freebsd-zfs (38G) swapinfo # swapinfo Device 1K-blocks Used Avail Capacity /dev/gpt/swap0 2097152 0 2097152 0% 19 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (7) zpool status -v # zpool status -v pool: zroot state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM zroot ONLINE 0 0 0 ada0p3 ONLINE 0 0 0 errors: No known data errors 20 Computer Center, CS, NCTU CS, Computer Center, Root On ZFS – (8) zfs list # zfs list NAME USED AVAIL REFER MOUNTPOINT zroot 657M 36.5G 344M legacy zroot/home 31K 36.5G 31K legacy zroot/tmp 36K 36.5G 36K /tmp zroot/usr 311M 36.5G 311M /usr zroot/usr/ports 95K 36.5G 33K /usr/ports zroot/usr/ports/distfiles 31K 36.5G 31K /usr/ports/distfiles zroot/usr/ports/packages 31K 36.5G 31K /usr/ports/packages zroot/usr/src 31K 36.5G 31K /usr/src zroot/var 461K 36.5G 126K /var zroot/var/crash 31.5K 36.5G 31.5K /var/crash zroot/var/db 116K 36.5G 85K /var/db zroot/var/db/pkg 31K 36.5G 31K /var/db/pkg zroot/var/empty 31K 36.5G 31K /var/empty zroot/var/log 45K 36.5G 45K /var/log zroot/var/mail 31K 36.5G 31K /var/mail zroot/var/run 48.5K 36.5G 48.5K /var/run zroot/var/tmp 32K 36.5G 32K /var/tmp 21 Computer Center, CS, NCTU