I’ve been looking at the capabilities of the Synology NAS products by looking over the Synology DiskStation 212j. This time around I gave it a spin as an iSCSI target from Windows Home Server 2011. There’s links at the end for more information about iSCSI, but for my purposes here it can be thought of as a way to present a network connected drive as a local drive to the operating system. The Synology NAS will be addressed by WHS 2011 as a local drive. No additional software is needed, it’s all built in to Synology and Windows Home Server.
This was configured using the Synology DiskStation 4 beta software although the DiskStation 3 software is set up the same way based on the information at the Synology website.
iSCSI Target Types
The Synology DiskStation software supports three different configuration types as an iSCSI LUN:
Regular Files – this configures the target on an already created file volume. This allows flexibility in allocating space. It can be increased anytime, as long as there’s space available on the volume.
Block Level (Single LUN on RAID) – this configures the target on available disks. There can’t be anything else on the disks used and they will be completely allocated. This provides the best performance (according to Synology). The disks can be configured for RAID.
Block Level (Multiple LUNs on RAID) – this configures the target on available disk space. Space already allocated to volumes can’t be used, but the disk(s) can be shared with file volumes.
The Synology website has good instructions on configuring iSCSI with their software so I won’t repeat it here. But for my simple requirements I was able to run through the wizard and accept the defaults. I didn’t set up any advanced options. When configuring a “Regular Files” LUN the size defaults to 1 GB so I did increase that to a more useful size.
Configuring iSCSI on Windows Home Server 2011 was a bit different than documented by Synology so I’ll run through it here. The configuration is the same for Windows 7 and Windows Storage Server 2008 R2 Essentials. I suspect Windows Server 2008 R2 is also the same along with the other related software such as Small Business Server 2008.
This needs to be done on the server itself so a Remote Desktop connection is needed (assuming the server is headless). Go to Control Panel and select “Set up iSCSI Initiator”. Then answer “Yes” to the prompt to start the iSCSI service.
The iSCSI properties dialog will appera – select discovery tab then click the “Discover Portal” button and enter the IP address (or DNS name) of the Synology NAS. Once the info is entered you should see the iSCSI target on the Synology NAS although it will still be listed as inactive. To establish the connection click the “Connect” button. In a strange twist of terminology you want to leave the default “Add this connection to the list of Favorite Targets” in order to make the connection persistent.
At this point the connection is established and the status will change to “Connected”. Once the connection is established you’ll need to switch over the “Disk Management” section of the Computer Management console.
When you click on “Disk Management” you’ll be prompted to initialize the disk. If the disk will be larger than 2 TB select “GPT” as the partition table type. Right-click on the newly added disk and select “New Simple Volume” from the context menu. Run through the wizard and when the wizard is done, so are you.
Now the disk can be used like any other local disk.
Performance isn’t a reason for doing iSCSI, at least not with a home network and a low-end Synology DS212j. It’s going to be slower than a local SATA drive, but since I can, I did some benchmarks.
This is Windows Home Server 2011 running on an HP MicroServer with relatively slow Western Digital 1TB Green Drives. It’s a Gigabit network using the MicroServer’s onboard NIC. When running the benchmarks I kept network traffic to a minimum, no streaming video or file copies, but I didn’t turn any devices off, so there was the normal background network traffic. Everything is connected to the same switch.
The DS212j had two 7200 RPM drives in it. One a Western Digital Caviar Black and the other a Hitachi HDT721010SLA360 drive. Both are on Synology’s compatibility list.
The first benchmarks show the local drives, the second shows a “Regular Files” iSCSI target.
I also set up each type of Block Level LUN and benchmarked them. The first is the Single LUN setup which should be the best performer, the second is a Multi LUN setup.
Being able to use the Synology boxes as an iSCSI target is a nice feature. Since it’s accessed over the network it’s not going to out perform a local drive unless you got a data-center class network to run it over. iSCSI doesn’t allow multiple PCs to access the same LUN (except with cluster aware software) since there’s no file locking, so it’s not a suitable replacement for a file share.
The more I explore the Synology software the more I’m considering one of their larger models. While I don’t see any immediate need to swap out anything I use for an iSCSI connected Synology NAS, I do think that an investment in a Synology DiskStation would eventually be used as an iSCSI connected drive somewhere in the future.