I went to Fry's this afternoon looking for a new case and a 5 bay SATA carrier to migrate my Windows Home Server over to a new system- but I chanced on a SuperMicro 743TQ-865B on closeout- for $85- This is a case that was originally going for $400 that I had drooled over- but found it to be way too much to justify the cost. NewEgg was selling it for $380- but again way too much money. Only the display was left so I grabbed a cart and had a Fry's salesperson write me up a ticket...
Once home, I began the long, arduous task of transferring all of my WHS data to staging location and then moving it back to the new server. Luckily I have been using a Promise NS4300N for backups and most of the data was already backed up (about 3.5TB of it, to be exact).
I purchased two new 1TB Seagate drives and built a RAID5 array with the existing four 1TB drives I had purchased for my WHS in the past. Once the build was complete, I had about 4.54TB available in a RAID5.
Due to limitations of MBR drives, partitions of larger than 2TB are not allowed- so I had to create a GPT partition to allow for the entire 4.54TB to be used.
This was acceptable to the Windows OS- but not very good for the WHS application. When I added the 4.54TB partition to WHS, it deleted the partition and re-created a MBR partition- allowing 2.0TB to be used for WHS storage and the other 2.6TB was resigned to 'system usage'. i.e. the system would not allow drives larger than 2TB to be added to WHS storage so it marked the rest of the storage as usable and called it 'system usage'- This is not what I wanted.
I read several blogs and this is normal for WHS as it was not designed to work with RAID systems. The blogs recommended creating smaller RAID groups of less than 2TB each. This was both impractical and undesirable when using 1TB drives as I would need to 9 drives to create three RAID5 groups- each having 2TB and giving me 6TB of total usable space (the other 3 drives would be allocated to the three RAID5s as parity data).
It also was not possible to create seperate 2TB partitions and present them to WHS as WHS looks at the disk and creates its own MBR partitions- ignoring anything over 2TB.
Additionally, I wanted to make the disk a dynamic disk so I would be able to grow the RAID5 if I needed additional storage in the future; not a good idea if WHS is managing the partitions and it suddenly grows by 1TB...
I eventually decided to leave the RAID5 as a stand-alone drive (i.e. not part of the WHS storage group). WHS uses C: for the system drive and D: for the 'data' drive so I made an N: drive as 4.54TB GPT dynamic disk.
The downsides of doing this is that I cannot manage shares on the E: drive via WHS and I cannot include this data in the WHS backup (which I found was not usable for NAS storage in the past). On the upside, I could still assign permissions as WHS creates local computer users.
WHS would be used for computer client backups for Tracy's and My PC and I would keep my pictures, music and user backups on the WHS storage disk. All other movies and videos would be stored on the N: drive.
I also added some single drives for WHS backups (of my music and photos) and to migrate my 'Mac Software' share from another single drive NAS (that wasn't very good as far as throughput goes):
I started off with a 150GB SATA drive for the WHS system drive, but quickly realized that the remaining 130GB of storage would not be sufficient for my backups; I was able to use Norton Ghost to clone the 150GB to a 1TB Western Digital drive I pulled out of the old WHS.
I did not want to waste the 1TB of space, so I put some one of my smaller videos shares on it (and since WHS creates a default 'video' share on the data drive, it seemed like a good idea), but his also filled up my 1TB drive fairly quickly (leaving me to purchase yet another 1TB drive from Fry's to balance it out). I considered adding the 1TB to my RAID5 but the new drive was a Maxtor (the Seagate drives were no longer on sale) and my RAID software would not allow me to add a seventy member.
In the end, I have eight 1TB drives and a dual bay external SATA storage
Now that I have the server configured with the RAID array outside of the WHS storage, the performance is MUCH better than it was before. WHS continues to write to a disk in the storage pool until it is full and then moves onto the next disk. If parallel file copies are made to a WHS share, this can cause delays as the write heads must jump around while trying to write to the same disk. If a file read is executed during this time, the accumulation of the two write actions and the read action make the heads jump all over the drive- killing throughput.
With the six platters all doing RAID5 read/write actions, several disk I/O operations can be implemented (and cached up for better execution in the RAID buffer) and performance is a bit better than trying to work with a single disk. Although I am not reaching full GB speed performance, I am averaging about 40MB/sec transfer speeds on large files across the network (theoretical speeds across a GB network could allow for up to 100MB/sec transfers -after allowing 20% for TCP/IP overhead).