how to add a disk to raid5 for dummies

[dpsmith]

hello,
i need to add a scsi disk to my raid5 array that has my datavg.
i ran out of space in folder/directory.
my rootvg is on 2 mirrored disks.
it's a rs6000 with AIX 4.3.
i got an exact match drive from IBM and am now preparing to install it.
do i just go into smit,choose backup volume group, choose datavg, and do a default back up?
or are there additional backup fields i should choose?

once i've backed up, i hotswap/insert the new drive and then what?
do i go into volume manager and remove the datavg volume and then recreate it with the additional drive and then restore the data?
is the rootvg the operating system?
will i still have all of SMIT when i wipe out datavg?
i'm fairly new to this and i'm having a hard time finding good info.
there is only one directory that needs to be expanded.
will the additional drive automatically expand all the directories in datavg or is that an additional step?
any tips or any websites that deal with this?
tia

 

[victorv]

Hi,
please, which kind of data are there on datavg ?
LV with raw data ?
JFS ? ( database or files ? )
is your datavg vg without FREE PP ?

However, smit and all system programs are in rootvg,
then when you destroy datavg, after appropriate backup
( savevg if data are in free files in jfs, or propretary
backup in case of db), you have all system going.

CASE of propretary db:
----------------------
Backup data.
Destroy datavg ( exportvg clears all from your system )
Destroy disk array
Remake new disk array
recreate datavg
recreate lv.

CASE of JFS:
save vg ( smitty vg, backup a volume gr.) ( yor data are on tape)
remove vg ( umount fs, delete vg or exportvg )
Destroy disk array
Remake new disk array
restore vg ( smitty vg, Remake VG ).

We can more precise, if tell us the kind of data.

bye.

 

[victorv]

Hi

While I was writing to you, I have seen yor reply.

How I was thinking Oracle is not on your system.

please show us the output of:

#lsvg datavg

#lsvg -l datavg

#lspv

The first gives an idea of size of total,free,used partitions.
The second show how it is used
The last gives an idea about vg are on disks

Bye

 

[dpsmith]

# lsvg datavg
VOLUME GROUP: datavg VG IDENTIFIER: 000ad55dc869c255
VG STATE: active PP SIZE: 64 megabyte(s)
VG PERMISSION: read/write TOTAL PPs: 271 (17344 megabytes)
MAX LVs: 256 FREE PPs: 30 (1920 megabytes)
LVs: 3 USED PPs: 241 (15424 megabytes)
OPEN LVs: 3 QUORUM: 2
TOTAL PVs: 1 VG DESCRIPTORS: 2
STALE PVs: 0 STALE PPs: 0
ACTIVE PVs: 1 AUTO ON: yes
MAX PPs per PV: 1016 MAX PVs: 32

# lsvg -l datavg
datavg:
LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
rims jfs 193 193 1 open/syncd /rims
test jfs 47 47 1 open/syncd /rims/test
loglv00 jfslog 1 1 1 open/syncd N/A


# lspv
hdisk0 000ad55d84bb82c3 rootvg
hdisk1 000ad55dcc76695c rootvg
hdisk2 000ad55dc869c06f datavg

as requested.

i do have some free space i can add to the RIMS volume.
so i have time to figure this out.
but i need to add another drive anyway.
the product is Qiclink from Trizetto.
thanks again

 

[victorv]

Hi,

You have 2 Gb free on your Raid disk (unpartitioned).

However, enter a df

and see if the first % in the /rims and /rims/test filesystmes is in effect near 100%.
If no, it is no an AIX problem.
If one of this is full, without delete any ( datavg, raidarrary ),

you can extend /rims jfs or (/rims/test) using

smitty jfs , change show, select jfs

modify the value increasing it of 10 or 15 %.

After this operation, reenter df and lsvg datavg, reuse smit jfs, if need, and consider the right moment to add the new disk, following the operations
indicated in the previous post (JFS case).

warning! DON'T umount /rims and /rims/test before
using smitty vg , savevg : savevg works on mounted jfs.

bye

 

[dpsmith]

how specific do i have to be to modify the value?
currently:
size of file system (in 512-byte blocks) [25296896]
the 25296896 isn't 25MB is it?
or is it 25296896 X 512 = roughly 13GB?
what number should i plug in to increase the size of /rims by a gigabyte?

do i add 2000000 to 25296896 to make it 27296896

is that right?

 

[dpsmith]

in case this helps


Change / Show Characteristics of a Journaled File System

Type or select values in entry fields.
Press Enter AFTER making all desired changes.

[Entry Fields]
File system name /rims
NEW mount point [/rims]
SIZE of file system (in 512-byte blocks) [25296896]
Mount GROUP []
Mount AUTOMATICALLY at system restart? yes +
PERMISSIONS read/write +
Mount OPTIONS [] +
Start Disk Accounting? no +
Fragment Size (bytes) 4096
Number of bytes per inode 4096
Compression algorithm no
Large File Enabled false
Allocation Group Size (MBytes) 8

 

[victorv]

Your jfs /rims stays in a lv /dev/rims of 193 logical
partitions; each on, in this vg values 64 Mb, then
your fs is 12352 Mb as you have seen
doing 25296896 * 1000 / 2 (more or less).

Then you are right, to add 1 Gb to your jfs, write
as new value 27296896; when the operation will finished
the new value may be different: sizes of jfs are
multiples of pp size (64 Mb in your vg).

 

[dpsmith]

thank you victorv!
i'm back down to 90% on my RIMS volume.

last stupid question:

was this what told you i had 2GB left?


FREE PPs: 30 (1920 megabytes)

 

[victorv]

Hi,
yes, dpsmit, it is.

On a disk, or better in a volume group, you have two types
of "free" space:

1) the free blocks of the single jfss;
( you see this by df command )
this areas are already allocated to the jfss and users
can use them (according with the permissions).

2) FREE PP ( Physical Partitions ), nobody can use these
until system admins create lv whit these to use as
jfs, paging, jfslog .

Seeing this in a PC vision, think an hard disk on PC,
managed by a program as Partitoin Magic:
you create on disk of 3 Gb, 2 partitions. The fisrt you call
C: and its size is 1Gb, the second is D: 1 Gb too.

Your C disk may be used at 60%, D at 10%, and you have
still 1Gb "Unpartitioned" of hard disk. By that program
you can enlarge C, reduce it (in AIX this is not possible),
and add another partition ( E for example).
In AIX, you make the same operation whit mklv,crfs,chfs,rmfs
commands, called from command line or indirectly by SMIT.

Bye.