I have a pair of ST31000528AS 3.5" SATA drives in a RAID-1 configuration. (1TB =~ 930GB usable).
I just upgraded this from a simple volume to a mirrored volume, using an identical (*) drive. This identical drive was a RMA replacement from Seagate, and is the exact model number, but there are some minor differences:
1) The Seagate Part Number differs, although the model number is the same --> could this perhaps be because it's a refurb drive?
2) The firmwares are not exactly the same. Original drive is CC46. Added drive is CC38. Current on Seagate's site is CC49. Interestingly, by putting in the S/N of the original drive, I get the warranty information (valid through 2015), and a recommendation to upgrade to CC49. But putting in the S/N from the refurb returned drive, I get similar warranty information (valid through 2015) and a notice that there are no firmwares offered. (Strange, no?)
At any rate, I notice the behavior of this drive/volume is such that after a while of inactivity, the drive has gone to sleep/standby, and requires a second or two to spin back up. Some Google-fu has taught me that this drive does not go into any kind of advanced power saving mode on its own, thus, it is commanded to a sleep state by the OS. In my case, that's Win7x64.
This is an Acer Veriton M680 system, with the Intel Rapid Storage Technology Onboard ROM version 18.104.22.1687.
After an overnight of leaving the system alone, I wake the system to find the mirror volume "degraded" - but upon hitting reset, it rebuilds the volume just fine, and all is fine and dandy.
My suspicions are as follows - but looking for confirmation here:
1) The iRST is detecting a false error due to spinup time and figuring one of the drives is timing out on response... but once it's spun up, it can reset and continue as normal. The rebuild succeeds and the drive is normal, until I leave the system alone long enough for it to go do it's power-save thing.
2) The difference in spinup time could be due to drive age, but could also be due to being different production runs, or any other number of factors. The different firmware levels could also be the culprit.
3) Lastly, this could also be an issue that has been corrected in a newer version of the Option ROM firmware (22.214.171.1247 --> newer version is 126.96.36.1997 I believe?) Acer does not show that 9.6.x download, but it's available here on Intel's website.
Does Intel recommend I:
- Synchronize the drive firmwares?
- Download the Intel Option ROM Software from Intel and update the Option ROM?
- Not use RAID 1?
I would like to get 2 more drives and go to RAID 10 but am concerned about doing so until I understand this behavior a little better.