Migrating from Linux to FreeBSD as a backend data store

In this talk I would like to discuss the process I went through in replacing a research file server’s OS from Linux to FreeBSD and that of its backup system. Initially, the system was hosting a custom 32bit Gentoo Linux instance and was able to host approximately 2.5TB of data over two file systems backed by a RAID-5 software RAID implementation.

Unfortunately, due to the physical layout of the software RAID instances, if a drive failed, it was easy to physically replace and to schedule a maintenance window. However, when it came time to insert the drive replacement back into the applicable RAID volume the performance penalty for rebuilding the RAID volume was rather high. This caused the system to become unresponsive when users were trying to query or engage the file server to launch new software instances.

The solution I implemented allowed me to leverage all the installed disks as one large ZFSv2 data volume by booting the system as a diskless FreeBSD system. I then utilized istgt (an iSCSI target software package) to offer a large disk to one of the group’s 64bit Gentoo Linux compute nodes whereby I could then launch autofs and racoon services (which in the Linux world means using IPSec to securely allow client machines to access file server resources in a very secure manner). The driving force behind using diskless FreeBSD is that if the research group wanted to expand their data store through the acquisition of additional storage gear the new server(s) could be booted as a diskless client, its disks configured as a ZFS data volume; leveraging istgt an additional disk would be offered to the 64bit Gentoo Linux compute node.

I would like to present this material to the BSDCan attendees to share my experience with others and to show that others can accomplish the same task without spending a large amount of money on proprietary software.