I have a RHEL 5.3 machine with the following partitions and free space:

Free space on the partitions
/ : 74GB
/boot : 81MB
/var : 73GB
/home : 37GB
/icat : 758MB
/opt : 1.5GB

Now is it possible to allot a free space of some other partitions to /opt? I want around 100 GB more space on /opt. Thus, if it is possible I could move 50GB from /var and /20 GB from /home to /opt. This can make at least 70 GB space available.
What are other possible ways to increase space on /opt?
Thanks in advance !!!

What you have shown is filesystem directories.

You should output the partitions info by using fdisk -l /dev/sdx.

Also specify which type of partition system is it. MSDOS or GPT.

Giving more info would help.

For other ways you can add a new hard disk drive and move /opt there.

yes, giving more info will help us to give better tips...
but in the meantime here is a link to check: http://gparted-forum.surf4.info/viewtopic.php?id=600

Thanks veerain for you comments. However, the exact command "fdisk -l /dev/sdx" did not give any output, hence attaching the output of "fdisk -l". Also the partition table is msdos.

Attached Files

fdisk_output.txt (1.8 KB, 16 views)

in general you should replace x, but fdisk -l was ok.
fdisk -l /dev/sda
fdisk -l /dev/sdb
fdisk -l /dev/sdc
also please post the output of the command: mount

Do these partitions need to be LVM enabled?

The output for mount is:

/dev/sdd2 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda6 on /home type ext3 (rw)
/dev/sda5 on /icat type ext3 (rw)
/dev/sdc2 on /var type ext3 (rw)
/dev/sdb2 on /opt type ext3 (rw)
/dev/sda2 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)

so now we can see /opt is located on /dev/sdb.
sdb has two partitions, sd2 is used for /opt. The size of the partition itself is almost 140 GB, but you use only 1.5 GB of it (that is the size of the filesystem).
You can also try:
cfdisk -P s /dev/sdb
parted -l /dev/sdb
df -h /dev/sdb2
just to be sure.
If it was really sure you can use resize2fs to increase the size of that filesystem because you have already space (which was not in use until now).

But beware, I cannot guarantee anything, you need to backup every important data before modifying your OS. You can only resize your filesystem if you boot another os (from usb, live disk).

The size of /dev/sdb2 is only 100GB. And thread starter has said only 15GB is free in /opt.

so I misunderstood something, but anyway it looks like there is free space on that drive. If that was not enough he need to use lvm or another disk or move something away from /opt onto another partition (which can be mounted under /opt)

Stats:

/var @ /dev/sdc2; Free space: 73GB; Total space 80GB
/dev/sdc total size 146.8GB partitions sdc1, sdc2 and sdc3
/dev/sdc3 Total size: 4GB Linux swap
You resize fs in sdc2 to 20GB. Delete sdc3 swap partition. Adjust partition size of sdc2 to 20GB. Recreate sdc3 with type swap of 4GB. Create sdc4 with rest of space (60GB) for /opt

/home @ /dev/sda6: Free space: 37 GB: Total space: 40GB
You resize fs in sda6 to 10GB. Adjust partition size of sda6 to 10GB. Create new extended partition with rest of space (30GB) /dev/sda7

So total accumulated space 30+60 = 90GB.

Free partitions /dev/sda7 (30GB), /dev/sdc4 (60GB).
And your /opt @ /dev/sdb2; Total space 100GB; free space 15GB.

Now the problem is /opt is using actively about 85GB. An you have to extend it with free space from above partitions.

One of our unifying option is LVM but would have to backup /opt first.

If you can't do that; then we are left with dmsetup (device mapper).

You using dmsetup program can create a block device unifying /dev/sdb2, /dev/sda7 and /dev/sdc4.
We use linear target of dmsetup to create a new block device combining all provided block devices.

Read dmsetup man page for that.

After combining use resize2fs to use whole space.

And you have to make a way of creating device mapper block device and mounting it as /opt at boot time before anything uses that.

Any help if needed please post.

Be CAREFUL or else you may loss your data.