Filesystem creation

[djessi]

Hi,

I am AIX admin, I am not used to solaris, I have created
a LUN on the EMC array and rebooted the system (solaris 10), I now see the device associated to the LUN. Next is to create 8 filesystems on it.
The problem is that when I print the partition table I only see 4 partitions unassigned whereas partition menu shows 0 to 7 partition. I don't understand how it works when I see partitions root, swap, usr, backup on this non-system disk (see display below).
Please help me understand and lead me for the next steps.

Thanks
Regards
Djessi

root@Kokala2 # format
Searching for disks...done
………………………………………………………………..
………………………………………………………………..
35. emcpower5a <DGC-RAID10-0326 cyl 32766 alt 2 hd 256 sec 32>
/pseudo/emcp@5
36. emcpower6a <DGC-RAID5-0326 cyl 63998 alt 2 hd 256 sec 64>
/pseudo/emcp@6
Specify disk (enter its number): 36
selecting emcpower6a
[disk formatted]

format> partition

PARTITION MENU:
0 - change `0' partition
1 - change `1' partition
2 - change `2' partition
3 - change `3' partition
4 - change `4' partition
5 - change `5' partition
6 - change `6' partition
7 - change `7' partition
select - select a predefined table
modify - modify a predefined partition table
name - name the current table
print - display the current table
label - write partition map and label to the disk
!<cmd> - execute <cmd>, then return
quit

partition> p
Current partition table (original):
Total disk cylinders available: 63998 + 2 (reserved cylinders)

Part Tag Flag Cylinders Size Blocks
0 root wm 0 - 15 128.00MB (16/0/0) 262144
1 swap wu 16 - 31 128.00MB (16/0/0) 262144
2 backup wu 0 - 63997 499.98GB (63998/0/0) 1048543232
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 usr wm 32 - 63997 499.73GB (63966/0/0) 1048018944
7 unassigned wm 0 0 (0/0/0) 0

 

[Annihilannic]

On a system with that many disks I would expect you to be using some kind of volume management software; are you sure this is not the case? It affects how you set up the disk.

Since Solaris typically gives some of the partitions special meanings (e.g. partition 2 covers the entire disk for backup purposes), you normally wouldn't create that many filesystems on a single disk using partitions; a volume manager (Solaris Volume Manager or Veritas Volume Manager for example, or even zfs) would make this much easier to do now, and easier to manage in the future.

Annihilannic.

 

[djessi]

Thank you for your advice,
Now, if I want to delete the devices created and re-start
the process of scanning new devices to see them on solaris,
what should I do ?

Thanks

Regards

Djessi

 

[elgrandeperro]

The raw disk devices will always appear to have 7 slices, because we use 3 bits of the 8 bit minor device word to specify slices in UFS. So you really can't "destroy" those devices, it is up to the partition table to say where on the disk to read and write.

So typically you repartion the disk and then newfs the filesystem which corresponds to that partition.

 

[KenCunningham]

...and perhaps consider soft partitions which enable creation of more than 7 slices.

Some days are diamonds, some days are rocks - make sure most are the former.

 

[Annihilannic]

Hmm... hadn't heard of soft partitions before. I read a bit here:

http://sysunconfig.net/unixtips/soft-partitions.html

But I don't see what advantages they have over normal SVM volumes, if any?

Annihilannic.

 

[elgrandeperro]

With soft partions, you can aren't limited to 7 metadevices referencing a single physical disk. I have seen 10s of soft partitions across a raid device.

 

[Annihilannic]

Oh, of course... I forgot that metadevice components each needed a partition of their own... thanks.

Annihilannic.