On 1/19/19 8:15 AM, Carsten Aulbert wrote:
Hi
On 1/19/19 2:09 PM, Basil Mohamed Gohar wrote:
This has been the case after multiple system starts/stops now over the
past few days.
Just for clarification, "starts/stops" refer to completely powered down
for several seconds - possibly even disconnected from power socket(s)?
Well, I can say fully powered-down, stopped spinning, no lights on
array. I did have the power unplugged once or twice during this.
If the former is the case, I would start to
(a) make a full backup of all data still on the RAID6
I have two drives of the 4-array RAID6 visible, but no files are
accessible because it's a RAID6, I need at least 3 of the 4 drives
working, and my problem is two are experiencing this problem.
(b) afterwards, start to swap cables/positions/connectors where
possible, note down waht you change and only change one piece at a time
This is challenging because it is in a tower array and all the drives
connect straight to motherboard-like backplane. I took one out and was
working with it directly via a USB SATA adapter, but that did not change
the errors I was seeing.
(c) as you get I/O errors right up front, are the disks seen by the
system at all? I.e. can hdparm/smartctl still access them or are they
more or less dead?
Yes, they are. SMART reports no fatal errors on the drives in questions!
Cheers
Carsten
What may help me is if there are any tools for md devices that let me
peek into the on-disk structure. Since the ext4 file system is spread
across the 3 data drives in the array, I cannot use, for example, e2fsck
on just one of them, and since I cannot properly assemble the drive, I
am somewhat stuck. Are there any tools for examining an array of drives
even if it is not recognized as such? I don't know, for example, if some
sectors went bad, how to tell mdadm to look in alternate locations
(i.e., akin to ext4's alternative superblock locations).
