4.5TB RAID5 Array (Promise TX4310 and 4x 1.5TB Seagates)

[ccb056]

I recently purchased 4x 1.5TB Seagate Drives (ST31500341AS) (http://www.seagate.com/ww/v/index.jsp?vgnextoid=511a8cf6a794b110VgnVCM100000f5 ee0a0aRCRD) and updated their firmwares to the latest (SD1A).

I also purchased a Promise FastTrak TX4310 (http://www.promise.com/product/product_detail_eng.asp?segment=RAID%205%20HBAS&product_id=165) and updated its firmware (2.8.1.4).

After building the RAID5 array, the logical disk size is 4.5TB (expected). Upon reboot, but before Windows loads, the Promise controller shows the logical disk size to be 2TB. Windows Server 2003 performs a checkdsk for a few minutes and then Windows finishes loading. After a second reboot, the RAID array is now gone and needs to be completely rebuilt. The data is lost.

I contacted Promise technical support by phone and they were aware of problems with using 1TB drives in a RAID5 array, but not of problems of using 1.5TB drives in a RAID5 array. Promise also stated they were working on a firmware fix for the controller and they should have a working firmware in 6 to 12 months.

In the mean time, I am using the disks in JBOD mode, and creating a software RAID5 array in Windows Disk Management (http://support.microsoft.com/kb/323434)

For those interested in creating a 4.5TB RAID5 array with these disks, I noticed that another RAID controller should be able to work in this setup.

The HighPoint RocketRAID 1740 (http://www.highpoint-tech.com/USA/rr1740.htm) controller does have 64bit LBA support which supports arrays greater than 2TB.

I hope this helps someone, if I had known this information sooner I would have purchased the HighPoint Controller instead of the Promise.

[tom_ozahoski]

It's unfortunate that happened to you. Are you able to return the Promise card? 6-12 months is ridiculous to fix a know problem. What are the drawbacks of using the software raid from windows?

[ccb056]

I purchased the card on eBay over a month ago so I do not expect to be able to return it.

I do not know what happens to the RAID array if I were to reformat Windows. Windows is installed on a PATA drive on my machine, the RAID is just used for storage. I have used Promise PATA RAID controllers in the past and I can pop the card and drives into any machine, install drivers, and use the array. I am not sure if I can remove the drives from this computer and install them in a different computer and still access the array and data.

What would be excellent is if Promise were to supply a method of conversion, so I can migrate from a Windows controlled array to a Promise controlled array without loosing data.

[noegruts]

After building the RAID5 array, the logical disk size is 4.5TB (expected). Upon reboot, but before Windows loads, the Promise controller shows the logical disk size to be 2TB. Windows Server 2003 performs a checkdsk for a few minutes and then Windows finishes loading. After a second reboot, the RAID array is now gone and needs to be completely rebuilt. The data is lost.

You are aware that the MBR system only supports partitions up to 2TB in size, right? For larger partitions, you need to use GPT (which you can't boot from, at least not yet).

[ccb056]

You are aware that the MBR system only supports partitions up to 2TB in size, right? For larger partitions, you need to use GPT (which you can't boot from, at least not yet).

Yes, and I have been building with GPT.

The problem lies in the hardware/firmware 32bit LBA, which limits the maximum capacity of logical drives to 2TB.

[noegruts]

Yes, and I have been building with GPT.

The problem lies in the hardware/firmware 32bit LBA, which limits the maximum capacity of logical drives to 2TB.

Fair enough. I know some other controller manufacturers workaround it by allowing larger-than-standard sector size, although that can cause other issues.

Good luck!