WMC Recording Drive iSCSI Target

[shortcut3d]

My goal is to have a small HTPC foot print that is energy efficient. My current setup is based on a 2011 Mac mini 2.7GHz Dual-Core Intel i7, 8GB RAM, 512GB Samsung 830 SSD, and 2TB 5400RPM Western Digital Green. The Mac mini is headless and I use Ceton Echo extenders (2) exclusively for playback (although the HTPC playback is better, but consistent UI speed masks the Echo short comings.) Tuner duties are handled by a Ceton InfiniTV6 ETH.

One thing I would like to improve is the Mac mini storage. The main issue is the 2TB 5400RPM WD Green drive is 15mm, which forces my drives to float on high density foam rubber spacers. If you've worked with Apple logic board connectors, you know floating drives is risky. Second, 2.5" drive capacity is not increasing very fast.

I initially started looking at a LaCie Big5 / Network+ / WHS2011 solution since I'm partial to their design, but have been personally impacted by LaCie reliability as of late. Trade shows got me thinking about Synology. Later confirmed through web benchmarks the performance of Synology out paces LaCie. I decide the Synology DS411slim was the best solution to meet my goals.

I know iSCSI targets as recording drives can be reliable, based on several 2011 post. However, there were not many configuration details or more current posts.

Question: Too what limit has an iSCSI target been pushed on WMC?

My plan is to configure the DS411slim to have one of four HGST 1TB 7200 as a basic volume setup as a block level iSCSI target. Based on reviews, this will provide the maximum throughput. The remaining 3 drives will be a RAID 5 volume shared over SMB. The single iSCSI target will be for recording and the RAID 5 volume will be for Blu-ray rips compressed with Handbrake. Is this over designed? Can I use a file level iSCSI target for 6 recordings?

[foxwood]

an I use a file level iSCSI target for 6 recordings?

Worst case scenario, you're looking at 60GB per hour (most of my channels compress to 5-6GB per hour, rather than 10GB/hour).

60GB/hour is about 17MB/s, or 130Mbps. That should be well within the limits for your system.

Note that your NIC will have to handle that traffic twice - inbound from the ETH6, and outbound to the Synology. You should be OK with a decent switch, but that's probably more likely to be a problem than the storage itself.

[shortcut3d]

Thank you for the verification. My calculations were based on an HD stream of 20Mbps x 6 = 120Mbps / 8 = 15MB/s. The worse write performance I could find in a review for the Synology DS411slim was 18MB/s. In most cases, it matched an internal HDD speed of a single drive.

[foxwood]

Thank you for the verification. My calculations were based on an HD stream of 20Mbps x 6 = 120Mbps / 8 = 15MB/s.

I've never bothered to check, but I guess in theory, the 6GB/hour that I record could have certain parts more heavily compressed than others, so that you would occassionally have higher throughput, but I'm fairly sure that the cable companies just set an upper limit, and it's somewhere below the 20Mbps that you might expect in an OTA recording, probably a lot closer to the 10-15Mbps that I see in real life.

[shortcut3d]

Thank you for the verification. My calculations were based on an HD stream of 20Mbps x 6 = 120Mbps / 8 = 15MB/s.

I've never bothered to check, but I guess in theory, the 6GB/hour that I record could have certain parts more heavily compressed than others, so that you would occassionally have higher throughput, but I'm fairly sure that the cable companies just set an upper limit, and it's somewhere below the 20Mbps that you might expect in an OTA recording, probably a lot closer to the 10-15Mbps that I see in real life.

So far testing seems good. I decided to use HGST 1TB 32MB Cache 7200RPM 2.5" drives in a Synology DS411slim. The iSCSI target was setup as a block level. I easily got over 70MB/s write on the NAS coming from the pokey internal 2TB WD20NPVT.

The problem I have has been with the Microsoft iSCSI initiator. It was going fine then suddenly stopped reconnecting after restarts. I did quite a bit of trouble shooting and it seems fine for now.

Best Practices for iSCSI.
- Static IP for both NAS and Windows 7 HTPC
- MsiSCSI Service set to Automatic
- Inbound/Outbound Windows Firewall Rules for iSCSI initiator Enabled

Solution for iSCSI Not Reconnecting After Restart.
- The target needs to be setup with the Local Adapter and Source IP Address, not default.
- Check multi-path

[shortcut3d]

My previous solution was not reliable from build to build.

I was able to resolve the iSCSI Favorite Target issue not reconnecting. I found the resolution on Technet. This requires the iSCSI target to appear in the list, but Inactive on reboot. The way to do this is to use default settings for everything.

I was able to successfully setup a Task without creating a .cmd script. The solution was to create a task on Trigger for Startup, with Conditions of Wait for Connection: Any, and Wait 30 seconds. The action was iscsicli qlogintarget <target_iqn>