storage

Recently I had an Oracle database server used by some developers that was running out of space on its data volume mounted at /u02. The volume was a simple MBR volume (think fdisk), so it couldn’t be non-destructively extended without using a third-party utility like gparted. That would have been fine, but rather than leave the volume as MBR, I decided to create a new iSCSI SAN-backed Logical Volume Manager (LVM) volume, which can be extended and resized pretty easily.

In this post, I’ll show you how to create a logical volume stored on an iSCSI SAN. Even though I did this on Red Hat Enterprise Linux 6.5 (RHEL), these steps should work on any distribution of Linux.

Recently I needed to build a multipurpose file server to host CIFS and NFS shares — CIFS for the Windows users, and NFS for VMWare to store ISOs. It needed to utilize back end storage (NetApp via iSCSI), provide Windows ACLs for the CIFS shares, and be able to authenticate against two different Active Directory domains. After careful consideration, I decided to use Red Hat Enterprise Linux 6.5 (RHEL) instead of Windows Server 2012.

Now you might be wondering, “Why on earth would you want to build a Linux file server to do all that when you can just use Windows?” There are a few reasons:

If you’re familiar with networking you know that when a device is directly connected to two separate IP networks, traffic destined for one of those networks should egress on the interface that is directly connected to that network. For example, if your storage appliance is directly connected to the 172.16.1.0/24 network, and you want to send a packet to a device with the IP of 172.16.1.55, traffic should egress on the interface connected to that network.

If you have a lot of duplicate data sitting around on laptops, USB drives, and external hard drives, you probably would like to clean it up and get back some of that wasted free space. But you probably don’t have time to go through and delete all the duplicates, or you’re concerned if you do you will mis-identify a duplicate and accidentally delete your only copy. I ran into this problem recently when I came dangerously close to running out of storage space on my NAS box which was running Freenas 0.