Configuring RAID-0 with Vinum

I deployed a test platform as a network security monitoring sensor. It has two 4 GB HDDs. I wanted to create a /nsm partition that would span both drives, meaning it would occupy some of the first drive and all of the second drive. This was a proof of concept operation that could apply to systems with multiple, larger drives.

I decided to use Greg Lehey's Vinum, and thanks to some helpful notes from Bamm Visscher and Dave Wheeler, got it set up in a RAID-0 configuration.

When I installed FreeBSD on the system, I created a 768 MB /nsm1 partition on the first drive ad0 and used the entire second drive (ad1) for /nsm2. Here is what df saw after installation. Notice I use the -m switch to show all values in MB.

bourque:/root# df -m
Filesystem  1M-blocks Used Avail Capacity  Mounted on
/dev/ad0s1a       247   35   192    16%    /
devfs               0    0     0   100%    /dev
/dev/ad0s1e       739    0   679     0%    /nsm1
/dev/ad1s1d      3977    0  3659     0%    /nsm2
/dev/ad0s1g       263    0   242     0%    /tmp
/dev/ad0s1d      1978  302  1517    17%    /usr
/dev/ad0s1f       495    0   455     0%    /var

Here is what bsdlabel saw for each drive:

bourque:/root# bsdlabel /dev/ad0s1
# /dev/ad0s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  a:   524288        0    4.2BSD     2048 16384 32776 
  b:   524288   524288      swap                    
  c:  8421777        0    unused        0     0         # "raw" part, don't edit
  d:  4194304  1048576    4.2BSD     2048 16384 28552 
  e:  1572864  5242880    4.2BSD     2048 16384 28552 
  f:  1048576  6815744    4.2BSD     2048 16384     8 
  g:   557457  7864320    4.2BSD     2048 16384 34848 

bourque:/root# bsdlabel /dev/ad1s1
# /dev/ad1s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  c:  8418753        0    unused        0     0         # "raw" part, don't edit
  d:  8418753        0    4.2BSD     2048 16384 28552 

Before I could use vinum, I needed to edit the disk labels so /dev/ad0s1e and /dev/ad1s1d changed from fstype 4.2BSD to vinum.

After running 'bsdlabel -e /dev/ad0s1' and 'bsdlabel -e /dev/ad1s1' here is what the two disks looked like to bsdlabel:

bourque:/root# bsdlabel /dev/ad0s1
# /dev/ad0s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  a:   524288        0    4.2BSD     2048 16384 32776 
  b:   524288   524288      swap                    
  c:  8421777        0    unused        0     0         # "raw" part, don't edit
  d:  4194304  1048576    4.2BSD     2048 16384 28552 
  e:  1572864  5242880     vinum                    
  f:  1048576  6815744    4.2BSD     2048 16384     8 
  g:   557457  7864320    4.2BSD     2048 16384 34848 

bourque:/root# bsdlabel /dev/ad1s1
# /dev/ad1s1:
8 partitions:
#        size   offset    fstype   [fsize bsize bps/cpg]
  c:  8418753        0    unused        0     0         # "raw" part, don't edit
  d:  8418753        0     vinum 

Next I created the following /etc/vinum.conf file. Notice for the drive sizes I used the values reported by 'df -m':

drive drive1 device /dev/ad0s1e
drive drive2 device /dev/ad1s1d
volume nsm
        plex org concat
        sd length 739m drive drive1
        sd length 3977m drive drive2

After editing /etc/vinum.conf, I ran vinum to create the RAID-0 system:

bourque:/root# create /etc/vinum.conf
2 drives:
D drive1                State: up       /dev/ad0s1e     A: 28/768 MB (3%)
D drive2                State: up       /dev/ad1s1d     A: 133/4110 MB (3%)

1 volumes:
V nsm                   State: up       Plexes:       1 Size:       4716 MB

1 plexes:
P nsm.p0              C State: up       Subdisks:     2 Size:       4716 MB

2 subdisks:
S nsm.p0.s0             State: up       D: drive1       Size:        739 MB
S nsm.p0.s1             State: up       D: drive2       Size:       3977 MB

That step created new devices for the vinum drive, as seen next:

bourque:/root# ls /dev/vinum/*
/dev/vinum/control      /dev/vinum/controld     /dev/vinum/nsm

/dev/vinum/plex:
nsm.p0

/dev/vinum/sd:
nsm.p0.s0       nsm.p0.s1

Now I needed to initialize the filesystem with newfs. The -U option enables soft updates:

bourque:/root# newfs -U /dev/vinum/nsm
/dev/vinum/nsm: 4716.0MB (9658368 sectors) block size 16384, fragment size 2048
        using 26 cylinder groups of 183.77MB, 11761 blks, 23552 inodes.
        with soft updates
super-block backups (for fsck -b #) at:
 160, 376512, 752864, 1129216, 1505568, 1881920, 2258272, 2634624, 3010976,
 3387328, 3763680, 4140032, 4516384, 4892736, 5269088, 5645440, 6021792,
 6398144, 6774496, 7150848, 7527200, 7903552, 8279904, 8656256, 9032608,
 9408960

When done I created a /nsm directory and mounted it:

bourque:/root# mkdir /nsm
bourque:/root# mount /dev/vinum/nsm
bourque:/root# df -h
Filesystem       Size   Used  Avail Capacity  Mounted on
/dev/ad0s1a      248M    36M   192M    16%    /
devfs            1.0K   1.0K     0B   100%    /dev
/dev/ad0s1e      739M   4.0K   680M     0%    /nsm1
/dev/ad1s1d      3.9G   4.0K   3.6G     0%    /nsm2
/dev/ad0s1g      263M   6.0K   242M     0%    /tmp
/dev/ad0s1d      1.9G   303M   1.5G    17%    /usr
/dev/ad0s1f      496M   370K   456M     0%    /var
/dev/vinum/nsm   4.5G   4.0K   4.1G     0%    /nsm

To enable this automatically, I added this line to /etc/fstab:

/dev/vinum/nsm          /nsm            ufs     rw              2       2

In /boot/loader.conf, I added these entries:

vinum_load="YES"
vinum.autostart="YES"

The older method of adding 'start_vinum="YES"' in /etc/rc.conf is still supported, but the new method is preferred.