1. Purpose

This document describes disks and filesystems.

2. scope

The Operation Checklist addresses the Filesystem creation /extention with disk process and defines usage instructions for creating and publishing checklists, preliminary configuration information and prerequisite requirements, procedural steps, and verification activities

3. Filesystem and disk

3.1 Add disks (LUNs) to volume group / logical volume

To add new LUNs to the system you can use the following procedure: The ticket or SAN team will inform the following information (probably under comments): cu:ldev of disk presented to Unix server via requested HBA.

The lun number points to the XP-ARRAY. This number is of no importance. The hwu number is the unique internal address to the storage. Use the following command to find out the corresponding device number:

Xpinfo will

#-> /usr/local/CPR/bin/xpinfo -il >xpinfo.output &

#-> grep -iE '40:90|40:91' /home/ssingh45/xpinfo.output |grep -i <array number>

/dev/rdisk/disk32 dc --- 00 CL5B 40:90 OPEN-V 00090451

/dev/rdisk/disk33 d1 --- 01 CL6B 40:91 OPEN-V 00090451

/dev/rdisk/disk34 d1 --- 01 CL6B 40:92 OPEN-V 00090451

/dev/rdisk/disk35 d1 --- 01 CL6B 40:93 OPEN-V 00090451

Depednig on the version of OS, cul:dev will give the device file output as legacy or persisteant device file (11.31)

3.2 Verificatoin of disk

# insf

(Note: if this does not work try 'insf -e' to force re-scanning of all devices). Search for devices (u = usable; quicker):

# ioscan –funCdisk

Create a physical volume for every physical device:

Check the disk provided by SAN is not been used and it is new on server.

#-> strings /etc/lvmtab |grep -i -e disk32 –e disk33 -e disk34 –e disk35

Above command should not return any output , it will show no disk are part of any VG/LV on the system.

#->

cat <<'EOF' >> ~ssingh45/disk.output

/dev/disk/disk32

/dev/disk/disk33

/dev/disk/disk34

/dev/disk/disk35

EOF

#-> cat ~ssingh45/disk.output |while read disk

> do

> pvdisplay $disk

> done

Expected output

pvdisplay: Warning: couldn't query physical volume "/dev/disk/disk24":

The specified path does not correspond to physical volume attached to

this volume group

3.3 Initialization of disk for filesystem creation

# pvcreate /dev/rdsk/c.t.d.

Physical volume "/dev/rdsk/c.t.d." has been successfully created.

If the system complains (because it finds the device is already in use) and you are sure the volume can be created, you can use the '-f' option to force the command:

# pvcreate -f /dev/rdsk/c.t.

Create the device directory for the volume group:

3.4 volume group creation

# mkdir /dev/VGNAME

Search for the next available major device number. First display the existing:

# ll /dev/*/group

> crw-r----- 1 root sys 64 0x000000 Nov 19 1999 group

> crw-r--r-- 1 root sys 64 0x020000 Dec 11 2002 group

> crw------- 1 root sys 64 0x010000 May 15 2001 group

Watch Out: The (hexadecimal) number after 64 is the node-number. Create a new one by choosing the next available, in this case 0x030000:

# mknod /dev/VGNAME/group c 64 0x030000

Now add the physical volumes to the volume group. When you don't use 'alternate pathing' (= two separate paths to same device) then you can leave out the last dev:

# vgcreate /dev/VGNAME /dev/dsk/c.t.d. /dev/dsk/c.t.d.

Volume group "/dev/VGNAME" has been successfully created.

Volume Group configuration for /dev/VGNAME has been saved in /etc/lvmconf/VGNAME.conf

Add the other physical volumes to the vg (if necessary):

LVM Parameter

Default Value

Maximum Value

Can be set by

Comments

Max # of Volume Groups

255

Kernel parameter maxvgs

HP-UX 11.11 – Default value in the OS image is 10.

HP-UX 11.23 - Default value in the OS image is 256.

HP-UX 11.31 – Kernel parameter is obsolete. The default value is 256 when using LVM 1.0.

# of physical volumes(PVs) per volume group(VG)

255

vgcreate –p <max_pv>

The default is too low and must be set when the volume group is created.

# of logical volumes(LVs) per Volume group(VG)

255

vgcreate –l <max_lv>

This setting can be left at the default setting or lowered.

Physical Extent size

4MB

256MB

vgcreate –s <pe_size>

Setting the pe_size has a direct impact on the max size of a single logical volume. The following table shows the correlation to this effect.

PE Size	Largest size of a single Logical Volume
4MB	256GB
8MB	512GB
16MB	1TB
32MB	2TB
64MB	4TB
128MB	8TB
256MB	16TB

Max # of Physical Extents(PE) per Physical Volume(PV)

1016

65535

vgcreate –e <max_pe>

Formula : pe_size * max_pe = Max size of usable disk.

Refer to Appendix 1 for a table of these values.

# vgextend /dev/VGNAME /dev/dsk/c.t.d. /dev/dsk/c.t.d.

Display the characteristics of the new volume group:

#vgdisplay -v VGNAME

--- Volume groups ---

VG Name /dev/VGNAME

VG Write Access read/write

VG Status available

Max LV 255

Cur LV 0

Open LV 0

Max PV 16

Cur PV 1

Act PV 1

Max PE per PV 1016

VGDA 2

PE Size (Mbytes) 4

Total PE 538

Alloc PE 0

Free PE 538

Total PVG 0

Total Spare PVs 0

Total Spare PVs in use 0

--- Physical volumes ---

PV Name /dev/dsk/c36t14d2

PV Name /dev/dsk/c37t14d2 Alternate Link

PV Status available

Total PE 538

Free PE 538

Autoswitch On

VG creation for distributed layout file system.

Physical volume groups can be created by using the "-g" option on the vgcreate and vgextend commands, or by manually editing the /etc/lvmpvg file. Refer to lvmpvg(4) man page for syntax.

Physical volume groups are used in conjunction with PVG-strict allocation policy. PVG-strict allocation ensures that primary and mirror extents do not reside within the same PVG. Typically each PVG consists of disk devices from the same controller card or set of controllers. Another example would be the case where LVs are mirrored between two separate disk arrays - the PVs in each of the arrays being assigned to separate PVGs.

Example /etc/lvmpvg file:

VG /dev/vgDist

PVG PVG1

/dev/dsk/c0t0d0

/dev/dsk/c0t1d0

/dev/dsk/c0t6d0

/dev/dsk/c0t7d0

PVG PVG2

/dev/dsk/c1t2d0

/dev/dsk/c1t3d0

/dev/dsk/c0t4d0

/dev/dsk/c0t5d0

vgextend –g PVG<NAME> /dev/VGNAME /dev/dsk/c.t.d. /dev/dsk/c.t.d. /dev/dsk/c.t.d. /dev/dsk/c.t.d. #four way distribution layout.

3.5 logical volume creation.

You can define a size in megabytes by using the '-L' option or in number of Physical Extents (PE's) by using the '-l' option.
If you want a size equal to the total available size you can use '-l' and the amount of 'Free PE's'
As default lvol1 is taken:

3.5.1 Strict logical creatoin

# lvcreate -l SIZE /dev/VGNAME

3.5.2 PVG-strict /distributed logical creation

# lvcreate -D y -s g -m 1 -L 1000 -n LVOL VGNAME

-D y specifies distributed allocation policy

-s g specifies PVG-strict allocation policy

-m 1 specifies 1 mirror copy

-L 1000 specifies size in MBytes = 1000

-n LVOL names logical volume VGNAME

3.5.3 Strip/distributed logical creatoin

# lvcreate -i 3 -I 32 -l 240 -n lvol1 /dev/VGNAME

Please use the parameter as per standard what exist on system or consult standard hpux guidline for Filesystem.

Now the devices should exist in the lvmtab:

# strings /etc/lvmtab|grep c.t.

# ll /dev/VGNAME

total 0

crw-r--r-- 1 root sys 64 0x0a0000 Dec 15 14:18 group

brw-r----- 1 root sys 64 0x0a0001 Dec 15 14:30 lvol1

crw-r----- 1 root sys 64 0x0a0001 Dec 15 14:30 rlvol1

Check the new volume group:

# vgdisplay -v /dev/VGNAME

create a filesystem on the nem logical volume:

# newfs -o largefiles -F vxfs /dev/VGNAME/rlvol.

version 3 layout

2203648 sectors, 2203648 blocks of size 1024, log size 1024 blocks

unlimited inodes, 2203648 data blocks, 2202000 free data blocks

68 allocation units of 32768 blocks, 32768 data blocks

last allocation unit has 8192 data blocks

first allocation unit starts at block 0

overhead per allocation unit is 0 blocks

Note that following command must be used to create new sapdata-filesystems:

# newfs -F vxfs -b 8192 /dev/VGNAME/rlvol

(blocksize of 8kB is needed by SAP/Oracle).

(blocksize of 1kB is needed by Redo / Mirr logs).

Create a mount-point:

# mkdir /.....

#-> cp -p /etc/fstab /etc/fstab.ssingh45-`date +%d-%m-%Y`

Add the necessary entries to /etc/fstab:

# vi /etc/fstab

Try to mount the new filesystems:

# mount -a

#mount -v # Mounting option as per file system.

Type of File System	Required Blocksize (use –o bsize with mkfs)	Required Mount options	Comments
Oracle redolog file systems	1K	largefiles,rw,mincache=direct,convosync=direct,delaylog,nodatainlog	Striping is not required. These file systems should not be on the same disks as the Oracle Indexes and Datafiles.
Oracle archive log file systems	1K	largefiles,rw,mincache=direct,convosync=direct,delaylog,nodatainlog	Striping is not required. Can be on the same disks as the Oracle redologs.
Oracle Indexes and Datafiles	8K	largefiles,rw,delaylog,nodatainlog	Striping is required. Create file systems using Distributing extent based Striping
General Purpose File systems	8K	largefiles,rw,delaylog,nodatainlog	Striping can be used but is not required. If striping is used, create the file system(s) using Distributed striping.

Set the permissions for the new top dir :

# chown ...:... /.....

# chmod ... /.....

Check the new situation:

# bdf

# vgdisplay -v /dev/VGNAME

3.6 Validaton of Filesystem creation

Check the layout of the Filesystem as per standard and requested.

#-> fstyp -v /dev/VGNAME/LVOL

vxfs

version: 6 <version of the VxFS>

f_bsize: 8192 ß This value represents the maximum block size that can be set. This value cannot be changed.

f_frsize: 2048 ß This value represents the fragmentation block size which was set using –o bsize option

f_blocks: 4612096 To understand more about f_bsize and f_frsize you can review the man page for statvfs

f_bfree: 4602773

f_bavail: 4458937

f_files: 1150720

f_ffree: 1150688

f_favail: 1150688

f_fsid: 1074987009

f_basetype: vxfs

f_namemax: 254

f_magic: a501fcf5

f_featurebits: 0

f_flag: 16

f_fsindex: 9

f_size: 4612096

#->lvdisplay -v /dev/VGNAME/LVOL

This will show the value and parameter which are used during the LV creation.

3.7 Adding the disk into secure path

Secure path is used for loadbalacing of I/O on the server. it is very important to set the policy as per guidline.

For 11.11 and 11.23

autopath discover

autopath display | grep -e /dev/dsk | awk '{print $1}' | while read device

autopath set_lbpolicy SST $device

done

For 11.31 :

For 11iv3 systems make sure the load balance policy is also set on the newly added disk:

Verify LB policy: scsimgr -p get_attr all_lun -a device_file -a load_bal_policy

Set LB policy on all disks: scsimgr save_attr -N "/escsi/esdisk" -a load_bal_policy=<LB policy>

Set LB policy on one disk: scsimgr save_attr -D /dev/rdisk/disk530 -a load_bal_policy=<LB policy>

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