Danieluwe

There is nothing else connected to the controller and the server hasn't even been doing anything, I've left it alone during the pre-clear, I checked the syslog, but there was nothing out of the ordinary on it, just normal ip lease requests and disc spindowns since the preclear started, I will wait for the preclear to finish before I start to worry too much, but is quite unusual never seen a drive speed vary so much during a preclear Ps just hit post read and back up to 120MB/s very strange

Just fitted a sil3132 card into my server to give a couple of extra slots, attached a new IBm 3tb coolspin and started the preclear, pre read ran through at between 120MB/s and 80MB/s pretty normal for my server, it has moved onto stage 2 copying zeros but has been running at 36MB/s consistently for the entire time I'm onto 22hrs elapsed and only 50% into writing zeros, Anyone have any idea what can cause this behaviour?? Many thanks in advance Dan

It indicates that three of the blocks read back DID NOT have all zeros as expected. This is the type of situation that causes hair loss (and parity checks that occasionally/constantly return parity errors) The cause can be a bad drive (we've seen this several times with other users) or a bad disk controller (also seen several times) or a bad power supply (power supply noise caused the writes to not function properly) or temperature (disks got too hot and were unable to read their own tracks because of thermal expansion) or vibration (disks shaking made them unable to write accurately) or even the motherboard chipset (nforce4 chipsets on early motherboards were prone to this) It cold also be your RAM, if it is not configured properly in your BIOS with the correct voltage, clock speed, and timing. (run a memtest overnight to eliminate it as a suspect) Good luck in isolating the issue. I'd not use that drive in that server connected/configured as it current is until you can get through several more pre-clear cycles with NO errors. Unfortunately, this class of error is frequently not detectable by any other test other than reading the contents of the disk. You might be lucky and see actual errors in the system log, but there are odds you will not see any error in the syslog and no errors in the smart report. I know, it is not good news... but I would not trust a server where the data I wrote was not readable accurately, even if it was only four times during the post-read. This class of error is EXACTLY why I added the post-read verify to the pre-clear script. Prior to it being added, there was no way to learn of the bad disk/controller/??? until AFTER it was in the array and you had stored data on it and subsequently dis a parity check. By then, it is MUCH harder to figure out which disk is causing the intermittent parity errors. Joe L. Many thanks for the quick reply, I've run a thorough memtest returning no errors and have run three WD EARS drives through a preclear with no problems, i will try another preclear before i get rid of the drive but pretty happy that the server hardware is up to scratch, Thanks again for the input it is appreciated.

Just got the following result on a preclear, not sure how to interpret the results Any help would be appreciated. Uploaded with ImageShack.us Many thanks in advance