Linux Server Configuration - Rackable Systems S3118 User Manual

For more information on setting up the iSCSI appliance server, please see the Rackable Systems S3118-
iSCSI Getting Started Guide, the Wasabi Quick Start manual, and the Wasabi Users Manual.

5.3 Linux Server Configuration

Many useful configurations of Linux are possible on the S3118. For overall stability, we recommend
installing a recent version of Red Hat or SuSE Linux.
The following section assumes moderate level Linux system administration skills. With relatively little
tuning, the S3118 server can become a high-performance Network-Attached Storage (NAS) server.
5.3.1 Operating System Installation
If your S3118 configuration includes a single or mirrored pair of boot drives accessible from the rear of the
server, you may want to consider installing the operating system there in order to provide an isolated boot
environment from the RAID. It is especially useful if you intend to use software RAID on the data drives.
Otherwise, install a boot partition (for /boot) on a small part of one of the RAID volumes (100-200 MB in
size may be sufficient), leaving the remaining capacity for data. Rackable also recommends a separate /
partition of at least 5 GB. To create the partitions, use a partitioning tool like parted or fdisk.
5.3.2 File System Selection
There are several production-quality file system choices available for Linux. Ext3 is the default Linux file
system. Although it is widely used and supports file system journaling, it does not provide as good
performance as the two other primary choices, Reiserfs and XFS. Reiserfs and XFS are also both high-
quality journaled file systems. Reiserfs is generally seen as higher performance than XFS for small file
transactional performance (and still significantly better than ext3 for large file streaming performance)
whereas XFS is generally seen as better at large file streaming performance than small file performance.
The Red Hat installer does not support XFS or Reiserfs by default. Newer releases of RHEL and Fedora
support XFS, Reiserfs, and JFS if you enable support for the file system when you boot the installer. (E.g.
for reiserfs, type "linux reiserfs".) When installing Red Hat Linux, we recommend keeping /boot,
and / as ext3. Other Linux distributions such as SuSE use Reiserfs as their default file system.
5.3.3 Data Drive Configuration (Hardware RAID)
When using hardware RAID, one SCSI device will be visible to the operating system for each hardware
RAID partition you created during the RAID card BIOS configuration stage. In Linux these devices will be
visible as /dev/sd<x> where <x> is a letter like "a", "b", "c", etc.
Once you have identified the correct device name, you will need to create a file system using the correct
method for the file system you have selected. For example, to create a Reiserfs file system on /dev/sda,
you would type "mkreiserfs /dev/sda".
After the file systems have been created, you will want to create mount points for them such as "/export1"
and "/export2" and add them to your /etc/vfstab file so that they are mounted on boot. Consider using the
"noatime,notail" options to optimize performance.
Finally "mount /export1 /export2" to mount the file systems and a "df" should now show the capacity as
being available.
5.3.4 Exporting File Systems
To export the file systems via NFS, you will need to add the required entries to the /etc/exports file. In
most cases, adding "no_subtree_check" is a good way to obtain a small increase NAS performance. If
your storage server is on a Uninteruptible Power Supply (UPS) or you can risk losing data in cache on a
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