Re: I/O hangs after resuming from suspend-to-ram

[Oleksandr Natalenko <oleksandr@natalenko.name>]

Hi.

Here is disk setup for QEMU VM:

===
[root@archmq ~]# smartctl -i /dev/sda
…
Device Model:     QEMU HARDDISK
Serial Number:    QM00001
Firmware Version: 2.5+
User Capacity:    4,294,967,296 bytes [4.29 GB]
Sector Size:      512 bytes logical/physical
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ATA/ATAPI-7, ATA/ATAPI-5 published, ANSI NCITS 340-2000
Local Time is:    Sun Aug 27 09:31:54 2017 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

[root@archmq ~]# lsblk
NAME                MAJ:MIN RM  SIZE RO TYPE   MOUNTPOINT
sda                   8:0    0    4G  0 disk   
`-sda1                8:1    0    4G  0 part   
  `-md0               9:0    0    4G  0 raid10 
    `-system        253:0    0    4G  0 crypt  
      |-system-boot 253:1    0  512M  0 lvm    /boot
      |-system-swap 253:2    0  512M  0 lvm    [SWAP]
      `-system-root 253:3    0    3G  0 lvm    /
sdb                   8:16   0    4G  0 disk   
`-sdb1                8:17   0    4G  0 part   
  `-md0               9:0    0    4G  0 raid10 
    `-system        253:0    0    4G  0 crypt  
      |-system-boot 253:1    0  512M  0 lvm    /boot
      |-system-swap 253:2    0  512M  0 lvm    [SWAP]
      `-system-root 253:3    0    3G  0 lvm    /
sr0                  11:0    1 1024M  0 rom

[root@archmq ~]# mdadm --misc --detail /dev/md0
/dev/md0:
        Version : 1.2
  Creation Time : Sat Jul 29 16:37:05 2017
     Raid Level : raid10
     Array Size : 4191232 (4.00 GiB 4.29 GB)
  Used Dev Size : 4191232 (4.00 GiB 4.29 GB)
   Raid Devices : 2
  Total Devices : 2
    Persistence : Superblock is persistent

    Update Time : Sun Aug 27 09:30:33 2017
          State : clean 
 Active Devices : 2
Working Devices : 2
 Failed Devices : 0
  Spare Devices : 0

         Layout : far=2
     Chunk Size : 512K

           Name : archiso:0
           UUID : 43f4be59:c8d2fa0a:a94acdff:1c7f2f4e
         Events : 485

    Number   Major   Minor   RaidDevice State
       0       8        1        0      active sync   /dev/sda1
       1       8       17        1      active sync   /dev/sdb1
===

In words: 2 virtual disks, RAID10 setup with far-2 layout, LUKS on it, then 
LVM, then ext4 for boot, swap and btrfs for /.

I couldn't reproduce the issue with single disk without RAID.

On neděle 27. srpna 2017 8:02:00 CEST Ming Lei wrote:
> On Sat, Aug 26, 2017 at 12:48:01PM +0200, Oleksandr Natalenko wrote:
> > Quick update: reproduced on both v4.12.7 and v4.13.0-rc6.
> 
> BTW, given it hangs during resume, it isn't easy to collect debug
> info, and there should have been lots useful info there.
> 
> You mentioned that you can reproduce it on QEMU, could you
> share the exact raid10 setting? such as which disks behind
> the raid10.
> 
> Or can you reproduce the issue without raid10 involved?
> 
> I will try to reproduce it in my VM if you may provide the
> above info.
> 
> Thanks,
> Ming