Thread: ZFS
View Single Post
Old 17th May 2008
TerryP's Avatar
TerryP TerryP is offline
Arp Constable
 
Join Date: May 2008
Location: USofA
Posts: 1,547
Default

I suggest you read this section and this wikipedia page.


To put it simple:

ad0 -> First PATA Hard Drive using FreeBSDs 'ad' driver.

ad0s1 -> first primary partition on ad0 -- also known as a 'slice'

ad0s1a -> partition 'a' within the disklabel for ad0s1

and so on.


BSD partitioning scheme is different from Linux or DOS and is fully documented.



The slice/partition notation should probably be reversed but I didn't invent the damn thing :\. One BSD slice is a lot like an Extended DOS Partition but you are not limted to haveing 1 of them and depending on the BSD flavor, 8-16partitons in side them in a manor comparable to logical drives.


Same concept from user point of view.

Unless you want to f*** around with things: /boot, /etc, and possibly /bin must be on the / because /boot is needed for bootstrapping. There is probably no sense in moving /sbin off the / either, the space gains not worth the bother unless your back in 1984.


Typical convention is to create either an a and b partition (/ and swap within the slice) or to create several partitions within one or more slices.

this is my OpenBSD systems layout:

Code:
Terry@vectra-$ df -hl
Filesystem     Size    Used   Avail Capacity  Mounted on
/dev/wd0a      147M   30.4M    110M    22%    /
/dev/wd0h      393M    938K    372M     0%    /home
/dev/wd0d     98.3M    6.0K   93.4M     0%    /tmp
/dev/wd0g      6.7G    400M    6.0G     6%    /usr
/dev/wd0e      148M   10.6M    130M     8%    /var
/dev/wd1a     11.8G   96.0M   11.1G     1%    /usr/local
/dev/wd1d     44.3G   12.2G   29.9G    29%    /srv
Terry@vectra-$
It functions as a headless file server and without X. The /home partition is small for storing local 'notes' and supported users actual files are stored under /srv/protocol/sharename and mounted over the network on the client system.



(at least modern) BSD systems generally name devices as driver major number [additional information].

i.e. xl0 -> first network interface using 'xl' driver, there is no eth0, eth1, etc -> it's all named by driver.

ad0 -> first pata drive on FreeBSD
da0 -> first scsi/usb drive on FreeBSD

wd0 -> first pata drive on OpenBSD
sd0 -> first sci/usb drive on OpenBSD

etc.


FreeBSDs file system uses soft updates and is gaining journaling support -> soft updates is a different way of filling the same need that journaling does.


Using ext3 under FreeBSD is mounted as ext2 -> and that means mounted without journaling so there is no point in using ext2/ext3 as a FreeBSD system slice.


UFS is better suited for system data.


Use FAT32/EXT2 for data to be shared with other OSes read+write, as ReiserFSv3 and JFS == read only in FreeBSD.
__________________
My Journal

Thou shalt check the array bounds of all strings (indeed, all arrays), for surely where thou typest ``foo'' someone someday shall type ``supercalifragilisticexpialidocious''.

Last edited by TerryP; 17th May 2008 at 06:34 PM.
Reply With Quote