topic Query: Expand logical volume in Operating System - HP-UX

Expand logical volume

Yurub — Fri, 07 Feb 2025 03:23:21 GMT

Hi,

We have an old system:

ia64 hp Integrity BL870c i4 .

HP-UX DB3 B.11.31 U ia64 ---- unlimited-user license

the storage structure was as follow:

RAID 01 with 10 HDD 600GB each and spare HDD with extra another HDD for later use.

the saconfig result was :

****-DB3#saconfig /dev/ciss1 ******************** SmartArray RAID Controller /dev/ciss1 ******************** Auto-Fail Missing Disks at Boot = enabled Cache Configuration Status = cache enabled Cache Ratio = 25% Read / 75% Write ---------- PHYSICAL DRIVES ---------- Location Ct Enc Bay WWID Size Status External 41 1 1 0x5000c5005832dc89 600.1 GB OK External 41 1 2 0x5000c5005832ea66 600.1 GB OK External 41 1 3 0x5000c50058329abd 600.1 GB OK External 41 1 4 0x5000c5005832a25e 600.1 GB OK External 41 1 5 0x5000c5005832dba9 600.1 GB OK External 41 1 6 0x5000c5005832f986 600.1 GB OK External 41 1 7 0x5000c5005832eea1 600.1 GB OK External 41 1 8 0x5000c50058328056 600.1 GB OK External 41 1 9 0x5000c5005832ed49 600.1 GB OK External 41 1 10 0x5000c5005832db4e 600.1 GB OK External 41 1 11 0x5000c5005832af7d 600.1 GB SPARE External 41 1 12 0x5000c50058328416 600.1 GB UNASSIGNED ---------- LOGICAL DRIVE 0 ---------- Device File = /dev/dsk/c4t0d0 RAID Level = 1+0 Size = 2560000 MB Stripe Size = 128 KB Status = OK Participating Physical Drive(s): Ct Enc Bay WWID 41 1 1 0x5000c5005832dc89 41 1 2 0x5000c5005832ea66 41 1 3 0x5000c50058329abd 41 1 4 0x5000c5005832a25e 41 1 5 0x5000c5005832dba9 41 1 6 0x5000c5005832f986 41 1 7 0x5000c5005832eea1 41 1 8 0x5000c50058328056 41 1 9 0x5000c5005832ed49 41 1 10 0x5000c5005832db4e Participating Spare Drive(s): Ct Enc Bay WWID 41 1 11 0x5000c5005832af7d

we had also a volume group vgora built on this disk

VG Name /dev/vgora VG Write Access read/write VG Status available Max LV 255 Cur LV 3 Open LV 3 Max PV 12 Cur PV 1 Act PV 1 Max PE per PV 33276 VGDA 2 PE Size (Mbytes) 64 Total PE 32767 Alloc PE 32738 Free PE 29 Total PVG 0 Total Spare PVs 0 Total Spare PVs in use 0 VG Version 1.0 VG Max Size 24957g VG Max Extents 399312 --- Logical volumes --- LV Name /dev/vgora/lvol1 LV Status available/syncd LV Size (Mbytes) 60032 Current LE 938 Allocated PE 938 Used PV 1 LV Name /dev/vgora/lvol2 LV Status available/syncd LV Size (Mbytes) 1766400 Current LE 27600 Allocated PE 27600 Used PV 1 LV Name /dev/vgora/lvol3 LV Status available/syncd LV Size (Mbytes) 268800 Current LE 4200 Allocated PE 4200 Used PV 1 --- Physical volumes --- PV Name /dev/disk/disk4 PV Status available Total PE 32767 Free PE 29 Autoswitch On Proactive Polling On

i ignored the result related to vg00

because we want to expand the lvol2 which is for /database

we added the spare and the UNASSIENED drive to the array

****-DB3#saconfig /dev/ciss1 ******************** SmartArray RAID Controller /dev/ciss1 ******************** Auto-Fail Missing Disks at Boot = enabled Cache Configuration Status = cache enabled Cache Ratio = 25% Read / 75% Write ---------- PHYSICAL DRIVES ---------- Location Ct Enc Bay WWID Size Status External 41 1 1 0x5000c5005832dc89 600.1 GB OK External 41 1 2 0x5000c5005832ea66 600.1 GB OK External 41 1 3 0x5000c50058329abd 600.1 GB OK External 41 1 4 0x5000c5005832a25e 600.1 GB OK External 41 1 5 0x5000c5005832dba9 600.1 GB OK External 41 1 6 0x5000c5005832f986 600.1 GB OK External 41 1 7 0x5000c5005832eea1 600.1 GB OK External 41 1 8 0x5000c50058328056 600.1 GB OK External 41 1 9 0x5000c5005832ed49 600.1 GB OK External 41 1 10 0x5000c5005832db4e 600.1 GB OK External 41 1 11 0x5000c5005832af7d 600.1 GB OK External 41 1 12 0x5000c50058328416 600.1 GB OK ---------- LOGICAL DRIVE 0 ---------- Device File = /dev/dsk/c4t0d0 RAID Level = 1+0 Size = 3072000 MB Stripe Size = 128 KB Status = OK Participating Physical Drive(s): Ct Enc Bay WWID 41 1 1 0x5000c5005832dc89 41 1 2 0x5000c5005832ea66 41 1 3 0x5000c50058329abd 41 1 4 0x5000c5005832a25e 41 1 5 0x5000c5005832dba9 41 1 6 0x5000c5005832f986 41 1 7 0x5000c5005832eea1 41 1 8 0x5000c50058328056 41 1 9 0x5000c5005832ed49 41 1 10 0x5000c5005832db4e 41 1 11 0x5000c5005832af7d 41 1 12 0x5000c50058328416 Participating Spare Drive(s): None

but to be noted we have used the free PE before the expansion of the RAID drive

which was:

--- Physical volumes --- PV Name /dev/disk/disk4 PV Status available Total PE 32767 Free PE 2681 Autoswitch On Proactive Polling On

now the problem is the:

we see that we have 3TB on disk4 , note that i cannot diskinfo /dev/disk/disk4, it says "Character device required " so i used rdisk/disk4

****-DB3#diskinfo /dev/rdisk/disk4 SCSI describe of /dev/rdisk/disk4: vendor: HP product id: LOGICAL VOLUME type: direct access size: 3145728000 Kbytes bytes per sector: 512

but the vgdisplay says:

****-DB3#vgdisplay vgora --- Volume groups --- VG Name /dev/vgora VG Write Access read/write VG Status available Max LV 255 Cur LV 3 Open LV 3 Max PV 6 Cur PV 1 Act PV 1 Max PE per PV 64000 VGDA 2 PE Size (Mbytes) 64 Total PE 32767 Alloc PE 32740 Free PE 27 Total PVG 1 Total Spare PVs 0 Total Spare PVs in use 0 VG Version 1.0 VG Max Size 24000g VG Max Extents 384000

that means: we have total of 32767 PE with 64MB which means a total of 2097088MB which is about 2TB while we have 3TB as "describe of /dev/rdisk/disk4:"

I tried many commands like ioscan, insf, vgreduce, but i stuck here.

sometimes i face that this device is character and this device is a block. and i dont know what to do.

in short: we cannot reflect the expansion of RAID drive to be aware by the volume group.

please help

Re: Expand logical volume

georgek_1 — Tue, 28 Jan 2025 04:39:29 GMT

Hello Yurub,

You need to use the command "vgmodify" to use the added to the disk, by adding new disks to the logical drive .
When a LUN is dynamically grown (DLE - Dynamic Lun Expansion - at the storage end , here at RAID) , vgmodify should be used to allow LVM to access this new space.
Once the volume group has been adjusted by vgmodify the new space can be allocated using the normal LVM method by lvextend or lvcreate.

You may need to use the command # vgmodify -v -r -a -E vg_name --> review mode , make sure that it is showing new disk size in output .
Now run without -r to make actual changes .

You may refer the White paper "Using the vgmodify command to perform LVM Volume Group Dynamic LUN Expansion (DLE) and Contraction (DLC)" from URL given below for more informaiton .
Section "Dynamic LUN expansion (DLE) and dynamic LUN contraction (DLC)" , page #6 onwards .

https://community.hpe.com/hpeb/attachments/hpeb/itrc-156/377793/1/356848.pdf

Please make sure you have good data backup before making any changes .

I work for HPE/ I am an HPE Employee (HPE Community)

Query: Expand logical volume

support_s — Wed, 29 Jan 2025 11:36:51 GMT

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Re: Query: Expand logical volume

Yurub — Mon, 03 Feb 2025 09:23:42 GMT

unfortunately it did not work

****-DB3#vgmodify -v -r -a -E vgora Volume Group configuration for /dev/vgora has been saved in /etc/lvmconf/vgora.conf An update to the Volume Group is NOT required Review complete. Volume group not modified

i also cannot tverify the size of /dev/disk/disk4

****-DB3#diskinfo /dev/disk/disk4 diskinfo: Character device required

but i can see the /dev/rdisk/disk4

****-DB3#diskinfo /dev/rdisk/disk4 SCSI describe of /dev/rdisk/disk4: vendor: HP product id: LOGICAL VOLUME type: direct access size: 3145728000 Kbytes bytes per sector: 512

Re: Query: Expand logical volume

georgek_1 — Mon, 03 Feb 2025 18:43:48 GMT

Hello Yurub,

I had a look at the configuration of the vg and it seems it is hitting a limit "Max PV Size (Tbytes)" of 2TB for vg with version 1 .
You could check the limits of different vg versions using # lvmadm -t . Below are the limits for vg version 1.0 which you have .

# lvmadm -t
--- LVM Limits ---
VG Version 1.0
Max VG Size (Tbytes) 510
Max LV Size (Tbytes) 16
Max PV Size (Tbytes) 2 =====>
Max VGs 256
Max LVs 255
Max PVs 255
Max Mirrors 2
Max Stripes 255
Max Stripe Size (Kbytes) 32768
Max LXs per LV 65535
Max PXs per PV 65535
Max Extent Size (Mbytes) 256

As per the table , the max size a disk can have is 2 TB .
The initial size of the disk (before adding new disks) was 2560000MB = 2500GB , which itself was above the limit .
After adding those 2 disks , the new size is 3072000 , ~3000GB which cannot be used in vg with version 1.0 .

****-DB3#vgdisplay vgora
--- Volume groups ---
VG Name /dev/vgora
VG Write Access read/write
VG Status available
Max LV 255
Cur LV 3
Open LV 3
Max PV 6
Cur PV 1
Act PV 1
...
Total PVG 1
Total Spare PVs 0
Total Spare PVs in use 0
VG Version 1.0 ==>

You have 2 options available ,

1)migrate the vg version from 1.0 to 2.x which will accommodate disks with higher size up to 16 TB , use the new size with help of vgmodify as shared earlier or 2) take data backup , recreate the array in such a way that there would be multiple logical volumes with size less than 2 tb so that all of these disks together can use be used make vg with version 1.0 and use all of the space .

You may refer #man vgversion for more information also make sure you have a good data backup before making any changes.

I work for HPE/ I am an HPE Employee (HPE Community)

Re: Query: Expand logical volume

Yurub — Tue, 04 Feb 2025 07:28:13 GMT

how can I migrate to version 2.0, i cannot find command vgconvert

while searching on google i found that it should be installed with patches earlier than 2008, I have this boundle but I dont have vgconvert!!

FEATURE11i B.11.31.1403.401a Feature Enablement Patches for HP-UX 11i v3, March 2014

Please help

Re: Query: Expand logical volume

georgek_1 — Tue, 04 Feb 2025 09:40:09 GMT

Hello Yurub,

The command is vgversion , which will help you migrate vg with version 1.0 to 2.x . There are multiple versions available such as 2.0 / 2.1 and 2.2 .

For example ,

Change the version of a volume group named /dev/vg01 to volume group
version 2.2 and be verbose:

vgversion -v -V 2.2 /dev/vg01

Please refer # man vgversion for more details / steps . also refer #lanadm -t for limits of each version .

I work for HPE/ I am an HPE Employee (HPE Community)

Re: Query: Expand logical volume

Yurub — Tue, 04 Feb 2025 22:02:47 GMT

Many Thanks

****-DB3#vgdisplay vgora --- Volume groups --- VG Name /dev/vgora VG Write Access read/write VG Status available Max LV 2047 Cur LV 3 Open LV 3 Cur Snapshot LV 0 Max PV 2048 Cur PV 1 Act PV 1 Max PE per PV 262144 VGDA 2 PE Size (Mbytes) 64 Unshare unit size (Kbytes) 1024 Total PE 47999 Alloc PE 40138 Current pre-allocated PE 0 Free PE 7861 Total PVG 1 Total Spare PVs 0 Total Spare PVs in use 0 VG Version 2.2 VG Max Size 24000g VG Max Extents 384000 Cur Snapshot Capacity 0p Max Snapshot Capacity 24000g

i have expanded some volumes and still have about 500GB for future use.

thank you

Re: Query: Expand logical volume

Yurub — Tue, 04 Feb 2025 22:57:44 GMT

thank you again

but i wonder, if I have 12 disks with 600GB on RAID 10, why I have 3TB not 3.6TB.

Re: Query: Expand logical volume

georgek_1 — Wed, 05 Feb 2025 18:06:17 GMT

Hello Yurub,

It seems like 50 gb is taken from each disk for raid - could be for parity writing , thus not available for user .
The size mentioned when the RAID has 10 disks was 2560000 MB .

Ideally, the size should be 600 (disk size) * 10 (no of disks) * 1024 (in MB) / 2 (since it is RAID10 - mirroring) = 3072000.

But the size available is 2560000 as shown below .

---------- LOGICAL DRIVE 0 ----------
Device File = /dev/dsk/c4t0d0
RAID Level = 1+0
Size = 2560000 MB ==>
Stripe Size = 128 KB
Status = OK

Thus we have almost 512000 MB (3072000 - 2560000)which is ~ 500GB missing when you have RAID with 10 disks configured .
So for a single disk it is 50gb (500gb/10 disks) non-usable for data writing .

When you added 2 new disks , the ideal size should be 600 * 12 * 1024 /2 = 3686400 MB ~ 3600GB .

But the current size is 3072000 MB .
---------- LOGICAL DRIVE 0 ----------

Device File = /dev/dsk/c4t0d0
RAID Level = 1+0
Size = 3072000 MB ==>
Stripe Size = 128 KB
Status = OK

So the missing size is again 3686400 - 3072000 = 614400 MB , ~ 600gb .
Which is nothing but addition of 100gb tp previous missing size (500gb) , 50 gb from each disk , thus 100gb for 2 new disks .

Hope this explains .

I work for HPE/ I am an HPE Employee (HPE Community)