Re: Reshape Failure

[Yu Kuai <yukuai1@xxxxxxxxxxxxxxx>]

Hi,

在 2023/09/06 22:05, Jason Moss 写道:
> Hi Kuai,
>
> I ended up using gdb rather than addr2line, as that output didn't give
> me the global offset. Maybe there's a better way, but this seems to be
> similar to what I expected.

It's ok.
> (gdb) list *(reshape_request+0x416)
> 0x11566 is in reshape_request (drivers/md/raid5.c:6396).
> 6391            if ((mddev->reshape_backwards
> 6392                 ? (safepos > writepos && readpos < writepos)
> 6393                 : (safepos < writepos && readpos > writepos)) ||
> 6394                time_after(jiffies, conf->reshape_checkpoint + 10*HZ)) {
> 6395                    /* Cannot proceed until we've updated the
> superblock... */
> 6396                    wait_event(conf->wait_for_overlap,
> 6397                               atomic_read(&conf->reshape_stripes)==0
> 6398                               || test_bit(MD_RECOVERY_INTR,

If reshape is stuck here, which means:

1) Either reshape io is stuck somewhere and never complete;
2) Or the counter reshape_stripes is broken;

Can you read following debugfs files to verify if io is stuck in
underlying disk?

/sys/kernel/debug/block/[disk]/hctx*/{sched_tags,tags,busy,dispatch}

Furthermore, echo frozen should break above wait_event() because
'MD_RECOVERY_INTR' will be set, however, based on your description,
the problem still exist. Can you collect stack and addr2line result
of stuck thread after echo frozen?

Thanks,
Kuai

> &mddev->recovery));
> 6399                    if (atomic_read(&conf->reshape_stripes) != 0)
> 6400                            return 0;
>
> Thanks
>
> On Mon, Sep 4, 2023 at 6:08 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
> > Hi,
> >
> > 在 2023/09/05 0:38, Jason Moss 写道:
> > > Hi Kuai,
> > >
> > > Thank you for the suggestion, I was previously on 5.15.0. I've built
> > > an environment with 6.5.0.1 now and assembled the array there, but the
> > > same problem happens. It reshaped for 20-30 seconds, then completely
> > > stopped.
> > >
> > > Processes and /proc/<PID>/stack output:
> > > root       24593  0.0  0.0      0     0 ?        I<   09:22   0:00 [raid5wq]
> > > root       24594 96.5  0.0      0     0 ?        R    09:22   2:29 [md0_raid6]
> > > root       24595  0.3  0.0      0     0 ?        D    09:22   0:00 [md0_reshape]
> > >
> > > [root@arch ~]# cat /proc/24593/stack
> > > [<0>] rescuer_thread+0x2b0/0x3b0
> > > [<0>] kthread+0xe8/0x120
> > > [<0>] ret_from_fork+0x34/0x50
> > > [<0>] ret_from_fork_asm+0x1b/0x30
> > >
> > > [root@arch ~]# cat /proc/24594/stack
> > >
> > > [root@arch ~]# cat /proc/24595/stack
> > > [<0>] reshape_request+0x416/0x9f0 [raid456]
> > Can you provide the addr2line result? Let's see where reshape_request()
> > is stuck first.
> >
> > Thanks,
> > Kuai
> >
> > > [<0>] raid5_sync_request+0x2fc/0x3d0 [raid456]
> > > [<0>] md_do_sync+0x7d6/0x11d0 [md_mod]
> > > [<0>] md_thread+0xae/0x190 [md_mod]
> > > [<0>] kthread+0xe8/0x120
> > > [<0>] ret_from_fork+0x34/0x50
> > > [<0>] ret_from_fork_asm+0x1b/0x30
> > >
> > > Please let me know if there's a better way to provide the stack info.
> > >
> > > Thank you
> > >
> > > On Sun, Sep 3, 2023 at 6:41 PM Yu Kuai <yukuai1@xxxxxxxxxxxxxxx> wrote:
> > > > Hi,
> > > >
> > > > 在 2023/09/04 5:39, Jason Moss 写道:
> > > > > Hello,
> > > > >
> > > > > I recently attempted to add a new drive to my 8-drive RAID 6 array,
> > > > > growing it to 9 drives. I've done similar before with the same array,
> > > > > having previously grown it from 6 drives to 7 and then from 7 to 8
> > > > > with no issues. Drives are WD Reds, most older than 2019, some
> > > > > (including the newest) newer, but all confirmed CMR and not SMR.
> > > > >
> > > > > Process used to expand the array:
> > > > > mdadm --add /dev/md0 /dev/sdb1
> > > > > mdadm --grow --raid-devices=9 --backup-file=/root/grow_md0.bak /dev/md0
> > > > >
> > > > > The reshape started off fine, the process was underway, and the volume
> > > > > was still usable as expected. However, 15-30 minutes into the reshape,
> > > > > I lost access to the contents of the drive. Checking /proc/mdstat, the
> > > > > reshape was stopped at 0.6% with the counter not incrementing at all.
> > > > > Any process accessing the array would just hang until killed. I waited
> > > >
> > > > What kernel version are you using? And it'll be very helpful if you can
> > > > collect the stack of all stuck thread. There is a known deadlock for
> > > > raid5 related to reshape, and it's fixed in v6.5:
> > > >
> > > > https://lore.kernel.org/r/20230512015610.821290-6-yukuai1@xxxxxxxxxxxxxxx
> > > >
> > > > > a half hour and there was still no further change to the counter. At
> > > > > this point, I restarted the server and found that when it came back up
> > > > > it would begin reshaping again, but only very briefly, under 30
> > > > > seconds, but the counter would be increasing during that time.
> > > > >
> > > > > I searched furiously for ideas and tried stopping and reassembling the
> > > > > array, assembling with an invalid-backup flag, echoing "frozen" then
> > > > > "reshape" to the sync_action file, and echoing "max" to the sync_max
> > > > > file. Nothing ever seemed to make a difference.
> > > >
> > > > Don't do this before v6.5, echo "reshape" while reshape is still in
> > > > progress will corrupt your data:
> > > >
> > > > https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@xxxxxxxxxxxxxxx
> > > >
> > > > Thanks,
> > > > Kuai
> > > >
> > > > > Here is where I slightly panicked, worried that I'd borked my array,
> > > > > and powered off the server again and disconnected the new drive that
> > > > > was just added, assuming that since it was the change, it may be the
> > > > > problem despite having burn-in tested it, and figuring that I'll rush
> > > > > order a new drive, so long as the reshape continues and I can just
> > > > > rebuild onto a new drive once the reshape finishes. However, this made
> > > > > no difference and the array continued to not rebuild.
> > > > >
> > > > > Much searching later, I'd found nothing substantially different then
> > > > > I'd already tried and one of the common threads in other people's
> > > > > issues was bad drives, so I ran a self-test against each of the
> > > > > existing drives and found one drive that failed the read test.
> > > > > Thinking I had the culprit now, I dropped that drive out of the array
> > > > > and assembled the array again, but the same behavior persists. The
> > > > > array reshapes very briefly, then completely stops.
> > > > >
> > > > > Down to 0 drives of redundancy (in the reshaped section at least), not
> > > > > finding any new ideas on any of the forums, mailing list, wiki, etc,
> > > > > and very frustrated, I took a break, bought all new drives to build a
> > > > > new array in another server and restored from a backup. However, there
> > > > > is still some data not captured by the most recent backup that I would
> > > > > like to recover, and I'd also like to solve the problem purely to
> > > > > understand what happened and how to recover in the future.
> > > > >
> > > > > Is there anything else I should try to recover this array, or is this
> > > > > a lost cause?
> > > > >
> > > > > Details requested by the wiki to follow and I'm happy to collect any
> > > > > further data that would assist. /dev/sdb is the new drive that was
> > > > > added, then disconnected. /dev/sdh is the drive that failed a
> > > > > self-test and was removed from the array.
> > > > >
> > > > > Thank you in advance for any help provided!
> > > > >
> > > > >
> > > > > $ uname -a
> > > > > Linux Blyth 5.15.0-76-generic #83-Ubuntu SMP Thu Jun 15 19:16:32 UTC
> > > > > 2023 x86_64 x86_64 x86_64 GNU/Linux
> > > > >
> > > > > $ mdadm --version
> > > > > mdadm - v4.2 - 2021-12-30
> > > > >
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sda
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68EUZN0
> > > > > Serial Number:    WD-WCC4N7AT7R7X
> > > > > LU WWN Device Id: 5 0014ee 268545f93
> > > > > Firmware Version: 82.00A82
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:27:55 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sda
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68EUZN0
> > > > > Serial Number:    WD-WCC4N7AT7R7X
> > > > > LU WWN Device Id: 5 0014ee 268545f93
> > > > > Firmware Version: 82.00A82
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:16 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sdb
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68EUZN0
> > > > > Serial Number:    WD-WXG1A8UGLS42
> > > > > LU WWN Device Id: 5 0014ee 2b75ef53b
> > > > > Firmware Version: 80.00A80
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:19 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sdc
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68EUZN0
> > > > > Serial Number:    WD-WCC4N4HYL32Y
> > > > > LU WWN Device Id: 5 0014ee 2630752f8
> > > > > Firmware Version: 82.00A82
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:20 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sdd
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68N32N0
> > > > > Serial Number:    WD-WCC7K1FF6DYK
> > > > > LU WWN Device Id: 5 0014ee 2ba952a30
> > > > > Firmware Version: 82.00A82
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Form Factor:      3.5 inches
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-3 T13/2161-D revision 5
> > > > > SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:21 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sde
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68EUZN0
> > > > > Serial Number:    WD-WCC4N5ZHTRJF
> > > > > LU WWN Device Id: 5 0014ee 2b88b83bb
> > > > > Firmware Version: 82.00A82
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:22 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sdf
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68AX9N0
> > > > > Serial Number:    WD-WMC1T3804790
> > > > > LU WWN Device Id: 5 0014ee 6036b6826
> > > > > Firmware Version: 80.00A80
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:23 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sdg
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68EUZN0
> > > > > Serial Number:    WD-WMC4N0H692Z9
> > > > > LU WWN Device Id: 5 0014ee 65af39740
> > > > > Firmware Version: 82.00A82
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:24 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sdh
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68EUZN0
> > > > > Serial Number:    WD-WMC4N0K5S750
> > > > > LU WWN Device Id: 5 0014ee 6b048d9ca
> > > > > Firmware Version: 82.00A82
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Rotation Rate:    5400 rpm
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:24 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > > $ sudo smartctl -H -i -l scterc /dev/sdi
> > > > > smartctl 7.2 2020-12-30 r5155 [x86_64-linux-5.15.0-76-generic] (local build)
> > > > > Copyright (C) 2002-20, Bruce Allen, Christian Franke, www.smartmontools.org
> > > > >
> > > > > === START OF INFORMATION SECTION ===
> > > > > Model Family:     Western Digital Red
> > > > > Device Model:     WDC WD30EFRX-68AX9N0
> > > > > Serial Number:    WD-WMC1T1502475
> > > > > LU WWN Device Id: 5 0014ee 058d2e5cb
> > > > > Firmware Version: 80.00A80
> > > > > User Capacity:    3,000,592,982,016 bytes [3.00 TB]
> > > > > Sector Sizes:     512 bytes logical, 4096 bytes physical
> > > > > Device is:        In smartctl database [for details use: -P show]
> > > > > ATA Version is:   ACS-2 (minor revision not indicated)
> > > > > SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> > > > > Local Time is:    Sun Sep  3 13:28:27 2023 PDT
> > > > > SMART support is: Available - device has SMART capability.
> > > > > SMART support is: Enabled
> > > > >
> > > > > === START OF READ SMART DATA SECTION ===
> > > > > SMART overall-health self-assessment test result: PASSED
> > > > >
> > > > > SCT Error Recovery Control:
> > > > >               Read:     70 (7.0 seconds)
> > > > >              Write:     70 (7.0 seconds)
> > > > >
> > > > >
> > > > > $ sudo mdadm --examine /dev/sda
> > > > > /dev/sda:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sda1
> > > > > /dev/sda1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0xd
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856376832 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247728 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : 8ca60ad5:60d19333:11b24820:91453532
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124311040 (118.55 GiB 127.29 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 23:12:08 2023
> > > > >      Bad Block Log : 512 entries available at offset 24 sectors - bad
> > > > > blocks present.
> > > > >           Checksum : b6d8f4d1 - correct
> > > > >             Events : 181105
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 7
> > > > >       Array State : AA.AAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sdb
> > > > > /dev/sdb:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sdb1
> > > > > /dev/sdb1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0x5
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856376832 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247728 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : 386d3001:16447e43:4d2a5459:85618d11
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124207104 (118.45 GiB 127.19 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 00:02:59 2023
> > > > >      Bad Block Log : 512 entries available at offset 24 sectors
> > > > >           Checksum : b544a39 - correct
> > > > >             Events : 181077
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 8
> > > > >       Array State : AAAAAAAAA ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sdc
> > > > > /dev/sdc:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sdc1
> > > > > /dev/sdc1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0xd
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856376832 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247720 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : 1798ec4f:72c56905:4e74ea61:2468db75
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124311040 (118.55 GiB 127.29 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 23:12:08 2023
> > > > >      Bad Block Log : 512 entries available at offset 72 sectors - bad
> > > > > blocks present.
> > > > >           Checksum : 88d8b8fc - correct
> > > > >             Events : 181105
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 4
> > > > >       Array State : AA.AAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sdd
> > > > > /dev/sdd:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sdd1
> > > > > /dev/sdd1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0x5
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856376832 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247728 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : a198095b:f54d26a9:deb3be8f:d6de9be1
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124311040 (118.55 GiB 127.29 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 23:12:08 2023
> > > > >      Bad Block Log : 512 entries available at offset 24 sectors
> > > > >           Checksum : d1471d9d - correct
> > > > >             Events : 181105
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 6
> > > > >       Array State : AA.AAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sde
> > > > > /dev/sde:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sde1
> > > > > /dev/sde1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0x5
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856376832 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247720 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : acf7ba2e:35d2fa91:6b12b0ce:33a73af5
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124311040 (118.55 GiB 127.29 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 23:12:08 2023
> > > > >      Bad Block Log : 512 entries available at offset 72 sectors
> > > > >           Checksum : e05d0278 - correct
> > > > >             Events : 181105
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 5
> > > > >       Array State : AA.AAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sdf
> > > > > /dev/sdf:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sdf1
> > > > > /dev/sdf1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0x5
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856373760 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247720 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : 31e7b86d:c274ff45:aa6dab50:2ff058c6
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124311040 (118.55 GiB 127.29 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 23:12:08 2023
> > > > >      Bad Block Log : 512 entries available at offset 72 sectors
> > > > >           Checksum : 26792cc0 - correct
> > > > >             Events : 181105
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 0
> > > > >       Array State : AA.AAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sdg
> > > > > /dev/sdg:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sdg1
> > > > > /dev/sdg1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0x5
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856373760 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247720 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : 74476ce7:4edc23f6:08120711:ba281425
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124311040 (118.55 GiB 127.29 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 23:12:08 2023
> > > > >      Bad Block Log : 512 entries available at offset 72 sectors
> > > > >           Checksum : 6f67d179 - correct
> > > > >             Events : 181105
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 1
> > > > >       Array State : AA.AAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sdh
> > > > > /dev/sdh:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sdh1
> > > > > /dev/sdh1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0xd
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856373760 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247720 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : 31c08263:b135f0f5:763bc86b:f81d7296
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124207104 (118.45 GiB 127.19 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 20:09:14 2023
> > > > >      Bad Block Log : 512 entries available at offset 72 sectors - bad
> > > > > blocks present.
> > > > >           Checksum : b7696b68 - correct
> > > > >             Events : 181089
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 2
> > > > >       Array State : AAAAAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --examine /dev/sdi
> > > > > /dev/sdi:
> > > > >       MBR Magic : aa55
> > > > > Partition[0] :   4294967295 sectors at            1 (type ee)
> > > > > $ sudo mdadm --examine /dev/sdi1
> > > > > /dev/sdi1:
> > > > >              Magic : a92b4efc
> > > > >            Version : 1.2
> > > > >        Feature Map : 0x5
> > > > >         Array UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >               Name : Blyth:0  (local to host Blyth)
> > > > >      Creation Time : Tue Aug  4 23:47:57 2015
> > > > >         Raid Level : raid6
> > > > >       Raid Devices : 9
> > > > >
> > > > >     Avail Dev Size : 5856373760 sectors (2.73 TiB 3.00 TB)
> > > > >         Array Size : 20497268736 KiB (19.09 TiB 20.99 TB)
> > > > >      Used Dev Size : 5856362496 sectors (2.73 TiB 3.00 TB)
> > > > >        Data Offset : 247808 sectors
> > > > >       Super Offset : 8 sectors
> > > > >       Unused Space : before=247720 sectors, after=14336 sectors
> > > > >              State : clean
> > > > >        Device UUID : ac1063fc:d9d66e6d:f3de33da:b396f483
> > > > >
> > > > > Internal Bitmap : 8 sectors from superblock
> > > > >      Reshape pos'n : 124311040 (118.55 GiB 127.29 GB)
> > > > >      Delta Devices : 1 (8->9)
> > > > >
> > > > >        Update Time : Tue Jul 11 23:12:08 2023
> > > > >      Bad Block Log : 512 entries available at offset 72 sectors
> > > > >           Checksum : 23b6d024 - correct
> > > > >             Events : 181105
> > > > >
> > > > >             Layout : left-symmetric
> > > > >         Chunk Size : 512K
> > > > >
> > > > >       Device Role : Active device 3
> > > > >       Array State : AA.AAAAA. ('A' == active, '.' == missing, 'R' == replacing)
> > > > >
> > > > > $ sudo mdadm --detail /dev/md0
> > > > > /dev/md0:
> > > > >               Version : 1.2
> > > > >            Raid Level : raid6
> > > > >         Total Devices : 9
> > > > >           Persistence : Superblock is persistent
> > > > >
> > > > >                 State : inactive
> > > > >       Working Devices : 9
> > > > >
> > > > >         Delta Devices : 1, (-1->0)
> > > > >             New Level : raid6
> > > > >            New Layout : left-symmetric
> > > > >         New Chunksize : 512K
> > > > >
> > > > >                  Name : Blyth:0  (local to host Blyth)
> > > > >                  UUID : 440dc11e:079308b1:131eda79:9a74c670
> > > > >                Events : 181105
> > > > >
> > > > >        Number   Major   Minor   RaidDevice
> > > > >
> > > > >           -       8        1        -        /dev/sda1
> > > > >           -       8      129        -        /dev/sdi1
> > > > >           -       8      113        -        /dev/sdh1
> > > > >           -       8       97        -        /dev/sdg1
> > > > >           -       8       81        -        /dev/sdf1
> > > > >           -       8       65        -        /dev/sde1
> > > > >           -       8       49        -        /dev/sdd1
> > > > >           -       8       33        -        /dev/sdc1
> > > > >           -       8       17        -        /dev/sdb1
> > > > >
> > > > > $ cat /proc/mdstat
> > > > > Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5]
> > > > > [raid4] [raid10]
> > > > > md0 : inactive sdb1[9](S) sdi1[4](S) sdf1[0](S) sdg1[1](S) sdh1[3](S)
> > > > > sda1[8](S) sdd1[7](S) sdc1[6](S) sde1[5](S)
> > > > >          26353689600 blocks super 1.2
> > > > >
> > > > > unused devices: <none>
> > > > >
> > > > > .
> > >
> > > .
>
> .