Offloaded data transfers (ODX) support was added in release 3.0.53 of the storage virtualization software. As with VAAI, offloaded data transfers enables high speed copy operations by offloading the entire copy operation to the array. This feature is beneficial for virtual machine (VM) clone operations, significantly reducing host CPU and network utilization. Users of ESXi will notice the similarities with VAAI third party / full copy primitive.
The Linear Tape File System utilities use a block size of 512 KB by default. When trying to format a tape using LTFS on a windows 2008 (possibly windows 2012) machine the formatting will fail and LTFS will complain that the maximum block size of the HBA adapter is less than 512 KB. To fix this problem do the following
Most of our linux installation are over the network using pxeboot, while the FreeBSD installations are using a usb stick. The reason for this that our servers do not have a DVD/CD-ROM drive. Recently we had to install Window Server 2012 on one of these servers and had to face many issues. Firstly lets highlight the issues we have
This article assumes that you have mt installed on your system.
For RHEL/CentOS this can be installed using the following command
# yum install mt-st
For FreeBSD mt can be installed using the following command
# pkg_add -r mt
For other distributions refer their respective documentation
Introduction to LTFS
Starting with LTO-5 drives a new technology called Linear Tape File System (LTFS) was introduced which allows for accessing tape media through a file-system interface. This is acheived by partitioning the tape into two, namely the data partition and the index partition. While the data partition contains the user data, the index partition can be thought of the partition containing metadata about the user data.
On unix systems the mtx utility is useful for media movement within a tape library. This article describes some of the most common commands for tape movement within a library. The mtx utility takes commands of the form
mtx -f <sg device> <command>
Tape devices usually have two device files a rewind and a no-rewind device. For example on Linux the first tape drive can be accessed using either /dev/st0 or /dev/nst0. Similarly on FreeBSD we have /dev/sr0 and /dev/nsr0. This article describes the difference between the two.
In this article we describe some of the common commands used for cinder volume configuration such as creating volumes, deleting volumes etc. Prior to using the command line examples you would need to source the required environment variables as described in http://docs.openstack.org/user-guide-admin/content/cli_openrc.html
Download lin_tape and lin_taped
Download the latest lin_tape source rpm and lin_taped binary rpm for your Linux distribution. In this article we are working with RHEL/CentOS and we have the following files downloaded
sh# ls -1 lin_tape* lin_tape-1.74.0-1.src.rpm lin_taped-1.74.0-rhel6.x86_64.rpm
Build lin_tape source
As superuser rebuild the lin_tape source rpm