Being slightly paranoid, I decided to build another server to mirror the 1.5TB of content on my WHS rig. Why? Well I like what I've accumulated and couldn't shake the concern that one day WHS might crap out on me leaving me without all my lovely movies/photos/music etc.
In addition, I want to apply Power Pack 1 and wasn't prepared to do that until my data was secure.
ExtemePC lives near me and had some free time today, so off we went to IT Estate where I bought 4 x 750gb Sammies and proceeded with the intention of resurrecting an old PC using XP Pro as the OS. The deal is that I'll simply copy everything over to the mirror then turn it off until there's more to copy across. I've configured two of the Sammies as a Dynamic Volume in the mirror (2 x 750gb = 1,500GB single volume).
This all went well until it was time to begin the copy process from WHS to the mirror. It was then that we noticed the horrendously slow network transfer speed (+/- 1.5MB/s on a GB network!!). Extreme uses an XP box as a server and achieves speeds across his network in excess of 55MB/s, and I can easily see similar network speeds between other PCs, so clearly something was wrong.
After a fair bit of troubleshooting nothing significant had turned up, and given that I had folder duplication (FD) turned on for approx 1TB of data leaving WHS 95% full, we began to suspect that FD was the problem caused by constant load balancing due to a lack of available space in the storage pool. So I turned off FD and my WHS console immediately reported the extra 1TB of available space. Strangely, when we cross checked this via Windows Disk Manager, we noticed that my drive capacity on all disks was still maxed out to almost 100% each - no changes had been made. Mmmm - curious!
I went back to the copy process and nothing had changed and transfers would not get above 2-3MB/s falling to around 1.5MB/s.
So to test the theory that it was load balancing problem, via RDP I created a share on my WHS C: drive and attempted to copy a 1.2GB file across from the storage pool to the new share. Now here's where it gets a little crazy. The transfer speed was exactly the same as the network speed - only remember this was from drive to drive within the same PC (+/- 1.5MB/s). Once the file had copied, using 2 different PCs on the same network the results were very different and more than a little surprising! The transfer speed from the new WHS share, (on C: drive and
not part of the storage pool) absolutely screamed through averaging more than 55MB/s and peaking at just over 60MB/s. Remember that this was from the same machine that I was getting 1.5MB/s out of the
storage pool for the very same file!!
At the time of writing and 2 hours after turning of folder duplication, my WHS drive manager is only now just starting to report that space is being freed up. The incremental space gains are so slow that it's clearly going to take all night for drive manager to reflect what the console has shown since turning off FD. Now this situation begs the question - what if I had tried to copy a large file across which exceeded the space which drive manager told me was available but the console reported as free? Frankly I wasn't game to try it but it might have been an interesting outcome!
So to summarise all this.
- Network transfer speeds from the storage pool are abysmal on almost maxed out disks with folder duplication turned on. At this point, no transfer speed tests have been performed after folder duplication has been turned off and load balancing has completed. I'll try this again tomorrow with 1TB of free space, no folder duplication and no load balancing occurring (assuming it ever stops!)
- Network transfer speeds from the same box but from a different drive which is not part of the WHS storage pool are at an expected speed over a GB network. We can therefore conclude that there was no network problem and that poor transfer performance (network & local) was solely due to load balancing. Constant checks were made on the CPU load and page file usage but nothing abnormal was evident with CPU activity never going above 10%.
- Significant changes made to the storage pool are shown in the WHS console a long time before the OS recognises that any change has occurred. So has the change really happened (yet) - who do you believe - the console or the operating system?
In closing, I love my WHS rig and have great faith in its backup functionality, however, I am slowly coming to the conclusion that as a media serving solution with multiple points to service, it might not be the best choice for me. My plan now is to have my media served to the household from the new (old) XP Pro box and use WHS as the mirror and of course my backup server. With up to 4 points to service with video etc. in my home, often simultaneously, I can't have a media server which cannot be relied upon to achieve transfer speeds over a GB network greater than 1.5MB/s to one PC. The XP box with a dynamic volume setup is having no trouble serving the same file to 4 separate points and hitting between 20 & 25MB/s to each.
I'm sure ExtremePC will add his comments to this since we were both somewhat blown away by what we discovered this afternoon.
Mike
