| The Cuddletech Veritas Volume Manager Series: Volume Kreation: VxAssist & Ways to spend more time cuddling | ||
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In our first lession we'll build a very simple volume. Let's make a 4G volume name "simplevol". The syntax for this creation will look like this:
vxassist -g <diskgroup> -U <usagetype> make <volname> <size> |
We discused the use of "-g" earlier. The "-U" can specify two types of usage: gen and fsgen. In effect, "gen" is a raw volume (charrector device only) and "fsgen" is a regular volume (charrector and block device). The only times I see people use "gen" type volumes is in coorlation with large database systems which sometimes use raw volumes rather than filesystems. We'll use the type "fsgen" for this course. The directive "make" tells vxassist that we want to make a volume. The "volname" is the name we want to give to the volume we're creating and "size" is the size of the volume to build. Size can be specified in the following forms: 1, 1m, 1g. That would be: 1 sector (512KB), 1 megabyte, and 1 gigabyte.
Now that we know the syntax, let's build it:
# vxassist -g cuddledg -U fsgen make simplevol 4g # vxprint -g cuddledg -hrt DG NAME NCONFIG NLOG MINORS GROUP-ID DM NAME DEVICE TYPE PRIVLEN PUBLEN STATE V NAME USETYPE KSTATE STATE LENGTH READPOL PREFPLEX PL NAME VOLUME KSTATE STATE LENGTH LAYOUT NCOL/WID MODE SD NAME PLEX DISK DISKOFFS LENGTH [COL/]OFF DEVICE MODE SV NAME PLEX VOLNAME NVOLLAYR LENGTH [COL/]OFF AM/NM MODE dg cuddledg default default 10000 1029129226.1248.gaff dm cuddle-f0 c1t0d0s2 sliced 3590 17678493 - dm cuddle-f1 c1t1d0s2 sliced 3590 17678493 - dm cuddle-f2 c1t2d0s2 sliced 3590 17678493 - dm cuddle-f3 c1t3d0s2 sliced 3590 17678493 - dm cuddle-f4 c1t4d0s2 sliced 3590 17678493 - dm cuddle-f5 c1t5d0s2 sliced 3590 17678493 - dm cuddle-f6 c1t6d0s2 sliced 3590 17678493 - dm cuddle-r0 c1t16d0s2 sliced 3590 17678493 - dm cuddle-r1 c1t17d0s2 sliced 3590 17678493 - dm cuddle-r2 c1t18d0s2 sliced 3590 17678493 - dm cuddle-r3 c1t19d0s2 sliced 3590 17678493 - dm cuddle-r4 c1t20d0s2 sliced 3590 17678493 - dm cuddle-r5 c1t21d0s2 sliced 3590 17678493 - dm cuddle-r6 c1t22d0s2 sliced 3590 17678493 - v simplevol fsgen ENABLED ACTIVE 8388608 SELECT - pl simplevol-01 simplevol ENABLED ACTIVE 8392167 CONCAT - RW sd cuddle-f0-01 simplevol-01 cuddle-f0 0 8392167 0 c1t0d0 ENA # |
Talk about simple! We've now got a volume enabled and ready for a filesystem. You'll notice that the volumes layout is "CONCAT", it's on one disk, it used the first disk it deemed usable to create the volume and built all the subobject. The volume is even started for us! This is why vxassist is so popular and helpful, it's very quick and easy.
Just for completeness let's see a filesystem put on this puppy and put into use:
# newfs /dev/vx/rdsk/cuddledg/simplevol
newfs: /dev/vx/rdsk/cuddledg/simplevol last mounted as /test
newfs: construct a new file system /dev/vx/rdsk/cuddledg/simplevol: (y/n)? y
/dev/vx/rdsk/cuddledg/simplevol:
8388608 sectors in 4096 cylinders of 32 tracks, 64 sectors
4096.0MB in 84 cyl groups (49 c/g, 49.00MB/g, 6144 i/g)
super-block backups (for fsck -F ufs -o b=#) at:
32, 100448, 200864, 301280, 401696, 502112, 602528, 702944, 803360, 903776,
1004192, 1104608, 1205024, 1305440, 1405856, 1506272, 1606688, 1707104,
1807520, 1907936, 2008352, 2108768, 2209184, 2309600, 2410016, 2510432,
2610848, 2711264, 2811680, 2912096, 3012512, 3112928, 3211296, 3311712,
3412128, 3512544, 3612960, 3713376, 3813792, 3914208, 4014624, 4115040,
4215456, 4315872, 4416288, 4516704, 4617120, 4717536, 4817952, 4918368,
5018784, 5119200, 5219616, 5320032, 5420448, 5520864, 5621280, 5721696,
5822112, 5922528, 6022944, 6123360, 6223776, 6324192, 6422560, 6522976,
6623392, 6723808, 6824224, 6924640, 7025056, 7125472, 7225888, 7326304,
7426720, 7527136, 7627552, 7727968, 7828384, 7928800, 8029216, 8129632,
8230048, 8330464,
# mkdir /simple_vol
# mount -F ufs /dev/vx/dsk/cuddledg/simplevol /simple_vol/
# cd /simple_vol/
# touch new_file
# ls -al
total 20
drwxr-xr-x 3 root root 512 Aug 11 23:24 .
drwxr-xr-x 33 root root 1024 Aug 11 23:23 ..
drwx------ 2 root root 8192 Aug 11 23:22 lost+found
-rw-r--r-- 1 root other 0 Aug 11 23:24 new_file
# |
There we have it, from start to finish, from SCSI disks to a usable volume with filesystem and it's even mounted. You'll notice that the device path is in the form: /usr/vx/(r)dsk/<diskgroup>/<volumename>. Everything else should be familar to you.
From this point on I will limit down the ammount of output, such as only showing the volume information in the vxprint output instead of all of it, and we won't cover creation of filesystems since you already know how to do that and every volume (regardless of how it's created) is created in a similar fashion as above. With that said, let's get onto the next lesson!