mkfs cannot open a device

[kyliu]

Dear Sir,
I connected a new storage on HP-UX 7400.
I could find it by using ioscan -fnCdisk command.
But I can't mount or make a new fild system on it .
I did this command "mkfs -F vxfs /dev/rdsk/c14t0d0", then I got a message "mkfs cannot open /dev/rdsk/c14t0d0".
Could you please help to solve this problem.
Thank you very much.

K.Y.

[Khairy]

hi kyliu,

in hpux, there is no direct disk use. You have to use LVM (logical volume manager).

Assuming vg04 is not being use in system, you can check this by typing the following command -> #vgdisplay

it will list any volume group that had been defined in system.

initialize the disk
# pvcreate -f /dev/rdsk/c14t0d0

Create a new volume group for your disk.
# mkdir /dev/vg04
# mknod /dev/vg04/group c 64 0x040000
# vgcreate /dev/vg04 /dev/dsk/c14t0d0

View your new volume group information
# vgdisplay -v vg04

The above command will list details about total size and disk member for vg04.

Now, create a new logical volume, let say you want a size of 500M.
# lvcreate -L 500M /dev/vg04

A new logical volume is create for vg04 and the name will be /dev/vg04/lvol1

Create vxfs filesystem
# newfs -F vxfs /dev/vg04/rlvol1

Create mount point and mount the new filesys.
# mkdir /data
# mount /dev/vg04/lvol1 /data

If you want the filesystem to be automount during reboot, add the entry accordingly in /etc/fstab file.

Good luck! Pls consider assign some points...thanks

[Ramesh S · Accepted solution]

Hi

Please check the device is visible and CLAIMED in ioscan.

If it is CLAIMED,
Try doing,

# insf -e -- To create special device files, if it is missing.

# diskinfo /dev/rdsk/cXtYdZ -- Verify the disk size.

# ll /dev/*/c14t0d0 -- Verify the device file available.

# newfs -F vxfs /dev/rdsk/cXtYdZ

-------------------------------------------

However, Using volume manager is the best option that whole disk approach. Whole disk approach has become absolute.

Limitations on Whole disk Approach are:

â ¢ Only one file system can exist on the disk. This means that you can't create a file system larger than the disk size.

â ¢ If you run short of space at a later stage, it is not possible to extend the file system. In another case,if you have allocated more space to a file system than is really needed, that space goes to waste, as there is no way to take it back. It may happen that you still have plenty of space on some of the file systems but you need some space on another file system that is full. If you are using the whole-disk
approach, you can't use this space for the file system that needs more space.These limitations are removed if you use Volume manager.

Thanks & Regards

Ramesh

[kyliu]

Dear two Sirs,
I have already to do all your steps.
but problem still here.
Do you have any way to solve this?
Thank you very much.
K.Y.

[kyliu]

addition information:
[gbm17400:/] #diskinfo /dev/rdsk/c15t0d0
SCSI describe of /dev/rdsk/c15t0d0:
vendor: IBM
product id: 3542
type: direct access
size: 0 Kbytes
bytes per sector: 0

[Bill Hassell]

> SCSI describe of /dev/rdsk/c15t0d0:
> vendor: IBM
> product id: 3542
> type: direct access
> size: 0 Kbytes
> bytes per sector: 0

This is a SAN disk array and the problem is that it has not been specified correctly to your server. The disk size is 0 which is the reason for all your failures. Talk to your SAN administrator about how the disk was presented to your system. The local HP-UX commands are fine but the disk array is not configured correctly.

[kyliu]

Dear Bill Hassell,
I connected this storage on HP-rp7410 for two years.
This case is Connecting on rp7400.
We bought eva storage this year,
So that I can't connect back to rp7410 for a test.

I checked both hosts' OS version as below.They are the same.

Is any probssible with HP-UX os or packages?
how do you think?

[gbm17410:/] #uname -a
HP-UX gbm17410 B.11.11 U 9000/800 4273052345 unlimited-user license

[gbm17400:/] #uname -a
HP-UX gbm17400 B.11.11 U 9000/800 604369303 unlimited-user license



Thank you very much.

[Bill Hassell]

Disk arrays, especially SAN devices are nothing like real disks. The controller hides the real disks and provides disk-like responses. Almost every SAN disk has specialized software to configure the storage and always incompatible between different arrays. Some vendors even provide special drivers which are required to make the storage work. You can check the previous computer that worked to see if there is a custom driver present.