Hi,

UNRaid noob here. I'm probably just misunderstanding something, but want to make sure .

 

Just completed my first build, and to prep for configuring the array, I ran pre-clear on 2 brand new 8TB drives (Seagate Ironwolfs).

 

The WebGUI Preclear plugin page's status says "Preclear Finished Successfully!" for both drives, and the post-preclear report (generated by the "eye" icon) also looks good.

However, the actual log has the warning

   "Zeroing: dd command failed, exit code: 1"

on  the dd command in the zeroing phase, from both  drives at the exact same location before the location where the pre-read ended. The post-read pass also stopped at the same location.

   Searching the forum, I've seen a couple of threads with the same error message, but it doesn't seem to be the same behavior: In those cases, the pre-clear stopped on the error, which it didn't in my case, or it was a HW issue (cable / bad SATA port) -- the fact that in my case  the error happened at the exact same disk location for both disks seems to rule that out.

 

Anything to worry about here? I'd rather not redoing the whole pre-clear unless really necessary.

 

Additional details:

UNRaid v6.3.1, plugin Pre-clear Disks 0.8.4-beta of 2017.02.16a

Pre-clear was run in parallel for both drives (pre- and post-read passes, one zeroing cycle); it took ~36 hours which seems reasonable.

Before  the pre-clear, I ran the short SMART test which passed fine (both drives).

Attached:

pre-preclear SMART tests, Post-preclear reports, preclear log.

Any additional info I can provide? I'm holding off on further pre-clears, reboots etc. so I don't clobber it.

 

ST8000VN0022-2EL112_ZA160BZK-20170313-0214.txt

ST8000VN0022-2EL112_ZA160HNB-20170313-0220.txt

post-preclear report ZA160BZK.txt

post-preclear report ZA160HNB.txt

The commands look completely correct, and the numbers look correct too.  Except for the first block, the entire drive was zeroed then post-read.  I see no reason for an error.  The only thing I can think of is that the zeroing command does not have an end, it just says keep zeroing until you can't, and that may mean it keeps zeroing blocks until it can't, which results in an error, which therefore is expected and can be ignored.

 

I think you can safely ignore that line in the log, as it did complete all of the zeroing and re-reading.

You might want to pose this issue in the thread for the preclear plugin.  You can find it here:

 

 

 

Thanks for the replies!

RobJ, what concerns me is that the pre- and post-read passes cover a different number of blocks.
Even if dd doesn't have an end specified when zeroing, I'd expect the pre-read pass to behave the same, and to have stopped at the same location.

Frank1940, my forum search didn't turn up that thread for some reason -- thanks, will repost there!
I've already seen at least 2 posts there about similar issues.

11 hours ago, GreenDolphin said:

RobJ, what concerns me is that the pre- and post-read passes cover a different number of blocks.

 

No, they are exactly correct, if you look closely at the commands.  In the pre-read, he reads the entire disk, including the first block.  In the zeroing and post-read, he skips the first block, then zeroes and tests the rest.  He's using a block size of 2MB (bs=2097152), and what is zeroed and post-read is exactly the entire disk minus one block.  You can subtract the 2 numbers and see.  To skip the first block, he uses skip=1 on the read and seek=1 on the write.  He must be handling the zeroing and signature writing in that first 2MB in another code section that isn't logged above.

 

11 hours ago, GreenDolphin said:

Even if dd doesn't have an end specified when zeroing, I'd expect the pre-read pass to behave the same, and to have stopped at the same location.

 

I don't know why, but apparently the read to the end stops without reporting an error, whereas the write does report an error, when it cannot write any more.