Need to add a disk space to my cluster that is on SAN (/dev/dm-*)

chrysek · 01-02-2007, 12:37 PM

Hello everyone, I just got those two linux redhat systems under my control and I am more of a Solaris guy and not linux amin so I have question on how to do this. I have few dysks setup, local and on SAN, I needed to add additional 200gb partition to a system that is on SAN and I am not sure how to do it so that I would not mess this up. Here is what I have:

[root@hog8 etc]# df -k
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroupRoot-LogVolRoot
15126920 3058052 11300460 22% /
/dev/sda1 101086 16104 79763 17% /boot
none 8147364 0 8147364 0% /dev/shm
/dev/mapper/VolGroupRoot-LogVolHome
20642428 159676 19434176 1% /home
/dev/mapper/VolGroupRoot-LogVolTmp
4063936 40916 3816584 2% /tmp
/dev/dm-8 20971520 20372352 599168 98% /ora01
/dev/dm-7 4194176 547840 3646336 14% /ora02
/dev/dm-6 211812224 131201664 80610560 62% /ora03
/dev/dm-5 210763648 210763520 128 100% /ora04
[root@hog8 etc]#

I added a new disk and I want to mount it as /ora04 but here how do I do it? how do I create /dev/dm-9 so I can then mount it?

When I run dmsetup ls

[root@hog8 etc]# dmsetup ls
3600508b40010536900004000038e0000 (253, 5)
VolGroupRoot-LogVolHome (253, 1)
3600508b4001053690000400003910000 (253, 6)
VolGroupRoot-LogVolSwap (253, 3)
3600508b4001053690000400003890000 (253, 7)
VolGroupRoot-LogVolRoot (253, 0)
3600508b4001053690000400004030000 (253, 9)
3600508b4001053690000400003840000 (253, 8)
3600508e000000000d7744575a7870c02 (253, 10)
VolGroupRoot-LogVolTmp (253, 2)
VolGroupRoot-LogVolSwap2 (253, 4)
[root@hog8 etc]#

I can see that disk here as:
3600508b4001053690000400004030000 (253, 9)

when I do multipath -ll I see the following:

[root@hog8 etc]# multipath -ll
3600508b40010536900004000038e0000
[size=201 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=10][active]
\_ 1:0:0:1 sdc 8:32 [active][ready]

3600508b4001053690000400003910000
[size=202 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=10][active]
\_ 1:0:0:2 sdd 8:48 [active][ready]

3600508b4001053690000400003890000
[size=4 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=50][active]
\_ 1:0:0:3 sde 8:64 [active][ready]

3600508b4001053690000400004030000
[size=200 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=50][active]
\_ 1:0:0:5 sdg 8:96 [active][ready]

3600508b4001053690000400003840000
[size=20 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=10][active]
\_ 1:0:0:4 sdf 8:80 [active][ready]

==================
this is the disk that I added (I am most certain that is the one)
3600508b4001053690000400004030000
[size=200 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=50][active]
\_ 1:0:0:5 sdg 8:96 [active][ready]

when I run fdisk -l I get the following output:

[root@hog8 etc]# fdisk -l

Disk /dev/sda: 72.9 GB, 72999763968 bytes
255 heads, 63 sectors/track, 8875 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 8875 71184015 8e Linux LVM

Disk /dev/sdc: 215.8 GB, 215822106624 bytes
255 heads, 63 sectors/track, 26238 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdc doesn't contain a valid partition table

Disk /dev/sdd: 216.8 GB, 216895848448 bytes
255 heads, 63 sectors/track, 26369 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdd doesn't contain a valid partition table

Disk /dev/sde: 4294 MB, 4294967296 bytes
133 heads, 62 sectors/track, 1017 cylinders
Units = cylinders of 8246 * 512 = 4221952 bytes

Disk /dev/sde doesn't contain a valid partition table

Disk /dev/sdf: 21.4 GB, 21474836480 bytes
64 heads, 32 sectors/track, 20480 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes

Disk /dev/sdf doesn't contain a valid partition table

Disk /dev/sdg: 214.7 GB, 214748364800 bytes
255 heads, 63 sectors/track, 26108 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Disk /dev/sdg doesn't contain a valid partition table
[root@hog8 etc]#

is /dev/sdg the disk that I added? how can I be sure that is the disk? If that is the disk how can I make it to look like /dev/dm-9 ?

when I look at /dev directory I already do see:
[root@hog8 etc]# ls -la /dev/dm*
brw-r----- 1 root root 253, 0 Dec 29 09:56 /dev/dm-0
brw-r----- 1 root root 253, 1 Dec 29 09:56 /dev/dm-1
brw-r----- 1 root root 253, 10 Dec 29 15:04 /dev/dm-10
brw-r----- 1 root root 253, 2 Dec 29 09:56 /dev/dm-2
brw-r----- 1 root root 253, 3 Dec 29 09:56 /dev/dm-3
brw-r----- 1 root root 253, 4 Dec 29 09:56 /dev/dm-4
brw-r----- 1 root root 253, 5 Dec 29 14:57 /dev/dm-5
brw-r----- 1 root root 253, 6 Dec 29 14:57 /dev/dm-6
brw-r----- 1 root root 253, 7 Dec 29 14:57 /dev/dm-7
brw-r----- 1 root root 253, 8 Dec 29 14:57 /dev/dm-8
brw-r----- 1 root root 253, 9 Dec 29 14:57 /dev/dm-9

does it mean its already created automatically?

My goal as I said is to create a partition and be able to mount it as /ora05 that is the 200GB partition from SAN.

Any help is greatly appreciated.

Regards,

Chris

chrysek · 01-02-2007, 12:56 PM

when I do ls -la on /dev
[root@hog8 dev]# ls -la | more
total 192
drwxr-xr-x 11 root root 5240 Jan 2 14:49 .
drwxr-xr-x 34 root root 4096 Dec 29 14:57 ..
crw------- 1 root root 36, 8 Dec 29 09:56 arpd
lrwxrwxrwx 1 root root 3 Dec 29 09:56 cdrom -> hda
lrwxrwxrwx 1 root root 4 Dec 29 09:57 cdrom1 -> scd0
crw------- 1 root root 5, 1 Dec 29 14:57 console
lrwxrwxrwx 1 root root 11 Dec 29 09:56 core -> /proc/kcore
drwxr-xr-x 6 root root 120 Dec 29 09:56 cpu
lrwxrwxrwx 1 root root 9 Dec 29 09:56 cpu0 -> cpu/0/cpu
lrwxrwxrwx 1 root root 9 Dec 29 09:56 cpu1 -> cpu/1/cpu
lrwxrwxrwx 1 root root 9 Dec 29 09:56 cpu2 -> cpu/2/cpu
lrwxrwxrwx 1 root root 9 Dec 29 09:56 cpu3 -> cpu/3/cpu
crw------- 1 root root 10, 63 Dec 29 09:56 device-mapper
brw-r----- 1 root root 253, 0 Dec 29 09:56 dm-0
brw-r----- 1 root root 253, 1 Dec 29 09:56 dm-1
brw-r----- 1 root root 253, 10 Dec 29 15:04 dm-10
brw-r----- 1 root root 253, 2 Dec 29 09:56 dm-2
brw-r----- 1 root root 253, 3 Dec 29 09:56 dm-3
brw-r----- 1 root root 253, 4 Dec 29 09:56 dm-4
brw-r----- 1 root root 253, 5 Dec 29 14:57 dm-5
brw-r----- 1 root root 253, 6 Dec 29 14:57 dm-6
brw-r----- 1 root root 253, 7 Dec 29 14:57 dm-7
brw-r----- 1 root root 253, 8 Dec 29 14:57 dm-8
brw-r----- 1 root root 253, 9 Dec 29 14:57 dm-9

does it mean that dm-9 is the disk that I am looking for?
it seems like dmsetup ls does show this disk as:
3600508b4001053690000400004030000 (253, 9)
and multipath -ll does show it as:
3600508b4001053690000400004030000
[size=200 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [prio=50][active]
\_ 1:0:0:5 sdg 8:96 [active][ready]

so in my opinion new 200gb disk that I allocated on SAN is /dev/dm-9 and to create ocfs2 file system I can simply run:
mkfs.ocfs2 -b 4K -C 128K -N 8 -L /ora05 /dev/dm-9

Does it seem right? Any input on this is greatly appreciated.

Chris