January 19, 20179 yr Community Expert Since nothing changed and it already happened twice I would expect the parity check/sync to fail again.
January 19, 20179 yr Author When it happened before more than these two drives dropped off the array and there were additional issue, I had error message on my console. It is consistent now that again these two drives have come up with errors. If I pull the second parity drive and do a pre clear on it, and it passes, I can put it back in the array later as a new second parity drive, correct? So what I am going to do, is pull the second parity drive out of the server and do a preclear on it to verify its bad. At the same time I am going to do a new config and run a parity check with just one parity drive now and see what happens. Sound like a good idea?
January 19, 20179 yr Community Expert I didn't notice the failed disks were the same 2, although before there was a 3rd failure after the first 2, but since it's the same 2 maybe try using them in different backplane slots, still strange that they would fail both at the same time.
January 19, 20179 yr Author Have started a parity check now with just one parity drive. Doing a preclear on the old parity 2 drive, will see what it comes up with.
January 19, 20179 yr Author This is going to sound odd, but the parity check has been running for almost five hours now and its already at 10.6% with one day and 12 hrs left. It feels like its running faster, although I know there is no logical reason for it to be. Anyway, time will tell what happens.
January 19, 20179 yr Community Expert It's normal, Q parity needs considerably more CPU power than P, the more disks you have the more noticeble it will be.
January 19, 20179 yr Author So a parity check with dual parity is slower and takes longer then a parity check with just one drive? With more disks it will take longer? Is that what you are saying?
January 19, 20179 yr Community Expert It will depend on the hardware used, if the CPU can't handle the extra load it will be slower, se here for some examples: http://lime-technology.com/forum/index.php?topic=51036.msg491331#msg491331
January 19, 20179 yr Author The fastest this card seems to go is 57MB/s, before on different hardware when I was using this card and ARC 16 port RAID controller together, I was getting over 100MB/s towards the end of the parity check and that was with dual parity.
January 20, 20179 yr Author This was on my old system dual core i5 and 16GB of RAM, not the current dual quad core Xeon with 52GB of ECC.
January 20, 20179 yr This was on my old system dual core i5 and 16GB of RAM, not the current dual quad core Xeon with 52GB of ECC. Note that your Xeon is probably an appreciably slower CPU than your i5 was. You didn't mention the specific i5 you were using, but I suspect it probably had a PassMark score roughly equal to the Xeon's 4875 ... but with half the cores; so the per-core performance of the i5 was nearly double that of your Xeon. Not sure that's the reason, but the 2nd parity calculation is far more CPU intensive than the basic parity used for the first parity disk.
January 20, 20179 yr Community Expert Gary is correct, single thread performance seems to be more important, I know from my own testing that a Pentium Dual Core G4400 (passmark 3618) is about 10% faster during dual parity checks than a Xeon E3-1220V2 (passmark 6557). Memory bandwidth also plays an important role.
January 20, 20179 yr Author So the passmark of my i5-2500 is 6245 with single thread rating of 1871, the passmark for my current xeon is 4875 with single thread rating of 1075 FYI. Interestingly enough, the speed on the parity check on my new server is now up to 88MB/s which is the fastest I've seen it so far with this card. I have found a drive on my array that is showing errors now, I hope it doesn't crap out my parity check which is 12.5 hrs away from finishing. 1 Raw read error rate 0x000f 118 100 006 Pre-fail Always Never 185481712 3 Spin up time 0x0003 091 091 000 Pre-fail Always Never 0 4 Start stop count 0x0032 097 097 020 Old age Always Never 3429 5 Reallocated sector count 0x0033 100 100 010 Pre-fail Always Never 0 7 Seek error rate 0x000f 078 060 030 Pre-fail Always Never 17424691335 9 Power on hours 0x0032 077 077 000 Old age Always Never 20942 (2y, 4m, 19d, 14h) 10 Spin retry count 0x0013 100 100 097 Pre-fail Always Never 0 12 Power cycle count 0x0032 100 100 020 Old age Always Never 111 183 Runtime bad block 0x0032 098 098 000 Old age Always Never 2 184 End-to-end error 0x0032 100 100 099 Old age Always Never 0 187 Reported uncorrect 0x0032 080 080 000 Old age Always Never 20 188 Command timeout 0x0032 100 001 000 Old age Always Never 1 1 161 189 High fly writes 0x003a 100 100 000 Old age Always Never 0 190 Airflow temperature cel 0x0022 066 038 045 Old age Always In the past 34 (8 35 34 28 0) 194 Temperature celsius 0x0022 034 062 000 Old age Always Never 34 (0 21 0 0 0) 195 Hardware ECC recovered 0x001a 118 100 000 Old age Always Never 185481712 197 Current pending sector 0x0012 100 100 000 Old age Always Never 0 198 Offline uncorrectable 0x0010 100 100 000 Old age Offline Never 0 199 UDMA CRC error count 0x003e 200 200 000 Old age Always Never 0 240 Head flying hours 0x0000 100 253 000 Old age Offline Never 3103h+23m+01.071s 241 Total lbas written 0x0000 100 253 000 Old age Offline Never 74467708364 242 Total lbas read 0x0000 100 253 000 Old age Offline Never 509130527037 Done
January 20, 20179 yr Author It looks like the preclear I am doing on what used to be my second parity drive is going to complete successfully. Wondering if I should put it back as a second parity drive or just as a data drive.
January 21, 20179 yr Author Alright so the parity check finished finally, all is good, only found 33 errors this time. Preclear on what used to be my second parity disk finished one pass successfully so that is good. Now just not sure if I am going to put that 8TB disk back as a second parity disk or as a data disk. Thoughts?
January 21, 20179 yr I think I'd investigate the disk that was showing errors in reply #66. Maybe use your spare disk to replace it? I'd also want to do file system checks. On an array with that many disks I'd be keen to have a second parity disk. Glad the new cable seems to have helped. Are you planning to stick with the SAS2LP?
January 21, 20179 yr Community Expert I'm glad if finished but IMO it's not really conclusive: Same cables/backplane and controller as the last time, you are not using parity2 but the disk seems fine and the other disk that failed twice before didn't fail this time, my money is still on the SAS2LP and some issue/compatibility with the expander/backplane.
January 21, 20179 yr Community Expert So the passmark of my i5-2500 is 6245 with single thread rating of 1871, the passmark for my current xeon is 4875 with single thread rating of 1075 FYI. Interestingly enough, the speed on the parity check on my new server is now up to 88MB/s which is the fastest I've seen it so far with this card. Not really surprising then, as your old CPU was considerably faster, especially on single thread performance. I have found a drive on my array that is showing errors now, I hope it doesn't crap out my parity check which is 12.5 hrs away from finishing. Although never good, those errors on some Seagates are more like reallocated sectors, you can see they were there on the first diagnostics you posted on this thread, so they are not new, but keep an eye on that disk or replace it if you want to play it safe. Device Model: ST5000DM000-1FK178 Serial Number: W4J01GH7 9 Power_On_Hours 0x0032 077 077 000 Old_age Always - 20867 183 Runtime_Bad_Block 0x0032 098 098 000 Old_age Always - 2 187 Reported_Uncorrect 0x0032 080 080 000 Old_age Always - 20
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