Re: The problems about COLO

[Daniel Cho <danielcho@qnap.com>]

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Hi  Lukas,
Thanks for your reply.

However, we test the question 1 with steps below the error message, we
notice the secondary VM's image
will break  while it reboots.
Here is the error message.
-------------------------------------------------------------------
[    1.280299] XFS (sda1): Mounting V5 Filesystem
[    1.428418] input: ImExPS/2 Generic Explorer Mouse as
/devices/platform/i8042/serio1/input/input2
[    1.501320] XFS (sda1): Starting recovery (logdev: internal)
[    1.504076] tsc: Refined TSC clocksource calibration: 3492.211 MHz
[    1.505534] Switched to clocksource tsc
[    2.031027] XFS (sda1): Internal error XFS_WANT_CORRUPTED_GOTO at line
1635 of file fs/xfs/libxfs/xfs_alloc.c.  Caller xfs_free_extent+0xfc/0x130
[xfs]
[    2.032743] CPU: 0 PID: 300 Comm: mount Not tainted
3.10.0-693.11.6.el7.x86_64 #1
[    2.033982] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[    2.035882] Call Trace:
[    2.036494]  [<ffffffff816a5ea1>] dump_stack+0x19/0x1b
[    2.037315]  [<ffffffffc01794eb>] xfs_error_report+0x3b/0x40 [xfs]
[    2.038150]  [<ffffffffc0138e6c>] ? xfs_free_extent+0xfc/0x130 [xfs]
[    2.039046]  [<ffffffffc01362da>] xfs_free_ag_extent+0x20a/0x780 [xfs]
[    2.039920]  [<ffffffffc0138e6c>] xfs_free_extent+0xfc/0x130 [xfs]
[    2.040768]  [<ffffffffc01a7736>] xfs_trans_free_extent+0x26/0x60 [xfs]
[    2.041642]  [<ffffffffc019fade>] xlog_recover_process_efi+0x17e/0x1c0
[xfs]
[    2.042558]  [<ffffffffc01a1e37>]
xlog_recover_process_efis.isra.30+0x77/0xe0 [xfs]
[    2.043771]  [<ffffffffc01a5761>] xlog_recover_finish+0x21/0xb0 [xfs]
[    2.044650]  [<ffffffffc0198894>] xfs_log_mount_finish+0x34/0x50 [xfs]
[    2.045518]  [<ffffffffc018ef21>] xfs_mountfs+0x5d1/0x8b0 [xfs]
[    2.046341]  [<ffffffffc017d220>] ? xfs_filestream_get_parent+0x80/0x80
[xfs]
[    2.047260]  [<ffffffffc0191d6b>] xfs_fs_fill_super+0x3bb/0x4d0 [xfs]
[    2.048116]  [<ffffffff81206ad0>] mount_bdev+0x1b0/0x1f0
[    2.048881]  [<ffffffffc01919b0>] ?
xfs_test_remount_options.isra.11+0x70/0x70 [xfs]
[    2.050105]  [<ffffffffc01906d5>] xfs_fs_mount+0x15/0x20 [xfs]
[    2.050906]  [<ffffffff81207349>] mount_fs+0x39/0x1b0
[    2.051963]  [<ffffffff811a7d45>] ? __alloc_percpu+0x15/0x20
[    2.059431]  [<ffffffff81223f77>] vfs_kern_mount+0x67/0x110
[    2.060283]  [<ffffffff81226483>] do_mount+0x233/0xaf0
[    2.061081]  [<ffffffff811a2cfb>] ? strndup_user+0x4b/0xa0
[    2.061844]  [<ffffffff812270c6>] SyS_mount+0x96/0xf0
[    2.062619]  [<ffffffff816b89fd>] system_call_fastpath+0x16/0x1b
[    2.063512] XFS (sda1): Internal error xfs_trans_cancel at line 984 of
file fs/xfs/xfs_trans.c.  Caller xlog_recover_process_efi+0x18e/0x1c0 [xfs]
[    2.065260] CPU: 0 PID: 300 Comm: mount Not tainted
3.10.0-693.11.6.el7.x86_64 #1
[    2.066489] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[    2.068023] Call Trace:
[    2.068590]  [<ffffffff816a5ea1>] dump_stack+0x19/0x1b
[    2.069403]  [<ffffffffc01794eb>] xfs_error_report+0x3b/0x40 [xfs]
[    2.070318]  [<ffffffffc019faee>] ? xlog_recover_process_efi+0x18e/0x1c0
[xfs]
[    2.071538]  [<ffffffffc019594d>] xfs_trans_cancel+0xbd/0xe0 [xfs]
[    2.072429]  [<ffffffffc019faee>] xlog_recover_process_efi+0x18e/0x1c0
[xfs]
[    2.073339]  [<ffffffffc01a1e37>]
xlog_recover_process_efis.isra.30+0x77/0xe0 [xfs]
[    2.074561]  [<ffffffffc01a5761>] xlog_recover_finish+0x21/0xb0 [xfs]
[    2.075421]  [<ffffffffc0198894>] xfs_log_mount_finish+0x34/0x50 [xfs]
[    2.076301]  [<ffffffffc018ef21>] xfs_mountfs+0x5d1/0x8b0 [xfs]
[    2.077128]  [<ffffffffc017d220>] ? xfs_filestream_get_parent+0x80/0x80
[xfs]
[    2.078049]  [<ffffffffc0191d6b>] xfs_fs_fill_super+0x3bb/0x4d0 [xfs]
[    2.078900]  [<ffffffff81206ad0>] mount_bdev+0x1b0/0x1f0
[    2.079667]  [<ffffffffc01919b0>] ?
xfs_test_remount_options.isra.11+0x70/0x70 [xfs]
[    2.080883]  [<ffffffffc01906d5>] xfs_fs_mount+0x15/0x20 [xfs]
[    2.081687]  [<ffffffff81207349>] mount_fs+0x39/0x1b0
[    2.082457]  [<ffffffff811a7d45>] ? __alloc_percpu+0x15/0x20
[    2.083258]  [<ffffffff81223f77>] vfs_kern_mount+0x67/0x110
[    2.084057]  [<ffffffff81226483>] do_mount+0x233/0xaf0
[    2.084797]  [<ffffffff811a2cfb>] ? strndup_user+0x4b/0xa0
[    2.085568]  [<ffffffff812270c6>] SyS_mount+0x96/0xf0
[    2.086324]  [<ffffffff816b89fd>] system_call_fastpath+0x16/0x1b
[    2.087161] XFS (sda1): xfs_do_force_shutdown(0x8) called from line 985
of file fs/xfs/xfs_trans.c.  Return address = 0xffffffffc0195966
[    2.088795] XFS (sda1): Corruption of in-memory data detected.  Shutting
down filesystem
[    2.090273] XFS (sda1): Please umount the filesystem and rectify the
problem(s)
[    2.091519] XFS (sda1): Failed to recover EFIs
[    2.092299] XFS (sda1): log mount finish failed
[FAILED] Failed to mount /sysroot.
.
.
.
Generating "/run/initramfs/rdsosreport.txt"
[    2.178103] blk_update_request: I/O error, dev fd0, sector 0
[    2.246106] blk_update_request: I/O error, dev fd0, sector 0
  -------------------------------------------------------------------

Here is the replicated steps:
*1. Start primary VM with command, and do every thing you want on PVM*
        qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 2048 -qmp
stdio -vnc :5 \
  -device piix3-usb-uhci,id=puu -device usb-tablet,id=ut -name primary \
  -netdev
tap,id=hn0,vhost=off,helper=/usr/local/ceph/libexec/qemu-bridge-helper \
  -device rtl8139,id=e0,netdev=hn0 \
  -drive
if=ide,id=colo-disk0,driver=quorum,read-pattern=fifo,vote-threshold=1,children.0.file.filename=$image_path,children.0.driver=qcow2
*2. Add the device and object to PVM with qmp command*
      {'execute':'qmp_capabilities'}
      {"execute":"chardev-add", "arguments":{ "id" : "mirror0", "backend" :
{ "type" : "socket", "data" : { "server": true, "wait": false, "addr": {
"type": "inet", "data":{ "host": "127.0.0.1", "port": "9003" } } } } }}
      {"execute":"chardev-add", "arguments":{ "id" : "compare1", "backend"
: { "type" : "socket", "data" : { "server": true, "wait": true, "addr": {
"type": "inet", "data":{ "host": "127.0.0.1", "port": "9004" } } } } }}
      {"execute":"chardev-add", "arguments":{ "id" : "compare0", "backend"
: { "type" : "socket", "data" : { "server": true, "wait": false, "addr": {
"type": "inet", "data":{ "host": "127.0.0.1", "port": "9001" } } } } }}
      {"execute":"chardev-add", "arguments":{ "id" : "compare0-0",
"backend" : { "type" : "socket", "data" : { "server": false, "addr": {
"type": "inet", "data":{ "host": "127.0.0.1", "port": "9001" } } } } }}
      {"execute":"chardev-add", "arguments":{ "id" : "compare_out",
"backend" : { "type" : "socket", "data" : { "server": true, "wait": false,
"addr": { "type": "inet", "data":{ "host": "127.0.0.1", "port": "9005" } }
} } }}
      {"execute":"chardev-add", "arguments":{ "id" : "compare_out0",
"backend" : { "type" : "socket", "data" : { "server": false, "addr": {
"type": "inet", "data":{ "host": "127.0.0.1", "port": "9005" } } } } } }
      {"execute":"object-add", "arguments":{ "qom-type" : "filter-mirror",
"id" : "m0", "props": { "netdev": "hn0", "outdev" : "mirror0", "queue" :
"tx" } } }
      {"execute":"object-add", "arguments":{ "qom-type" :
"filter-redirector", "id" : "redire0", "props": { "netdev": "hn0", "indev"
: "compare_out", "queue" : "rx" } } }
      {"execute":"object-add", "arguments":{ "qom-type" :
"filter-redirector", "id" : "redire1", "props": { "netdev": "hn0", "outdev"
: "compare0", "queue" : "rx" } } }
      {"execute":"object-add", "arguments":{ "qom-type" : "iothread", "id"
: "iothread1", "props": {} } }
      {"execute":"object-add", "arguments":{ "qom-type" : "colo-compare",
"id" : "comp0", "props": { "primary_in" : "compare0-0", "secondary_in" :
"compare1", "outdev" : "compare_out0", "iothread" : "iothread1"} } }
*3. Start the secondary VM with command*
        qemu-system-x86_64 -enable-kvm -cpu qemu64,+kvmclock -m 2048 -qmp
stdio \
  -vnc :6 -device piix3-usb-uhci -device usb-tablet -name secondary \
  -netdev
tap,id=hn0,vhost=off,helper=/usr/local/ceph/libexec/qemu-bridge-helper \
  -device rtl8139,id=e0,netdev=hn0 \
  -chardev socket,id=red0,host=127.0.0.1,port=9003,reconnect=1 \
  -chardev socket,id=red1,host=127.0.0.1,port=9004,reconnect=1 \
  -object filter-redirector,id=f1,netdev=hn0,queue=tx,indev=red0 \
  -object filter-redirector,id=f2,netdev=hn0,queue=rx,outdev=red1 \
  -object filter-rewriter,id=rew0,netdev=hn0,queue=all \
  -drive if=none,id=colo-disk0,file.filename=$image_path,driver=qcow2,\
node-name=node1 \
  -drive
if=ide,id=active-disk0,driver=replication,mode=secondary,file.driver=qcow2,\
top-id=active-disk0,file.file.filename=active-disk.qcow2,\
file.backing.driver=qcow2,file.backing.file.filename=hidden-disk.qcow2,\
file.backing.backing=colo-disk0,node-name=node2 \
  -incoming tcp:0:9998
*4. As the document create rbd server and do migrate with qmp command*
[image: image.png]
*5. Kill the PVM and failover to SVM*
[image: image.png]
*6. Reboot the secondary VM, then we will get the error.*
It is high possibility to occur this error.

Therefore, we can solve the image problem by *xfs_repair*, then reboot the
VM it will work.
Command:
xfs_repair -L /dev/sda1

Do you have any idea to occur this problem?

Best regard,
Daniel Cho.

Lukas Straub <lukasstraub2@web.de> 於 2019年11月5日 週二 上午2:37寫道：

> On Thu, 31 Oct 2019 17:05:20 +0800
> Daniel Cho <danielcho@qnap.com> wrote:
>
> > Hello all,
> > I have some questions about the COLO.
> > 1)  Could we dynamic set fault tolerance feature on running VM?
> > In your document, the primary VM could not  start first (if you start
> > primary VM, the secondary VM will need to start), it means to if I
> > want this VM with fault-tolerance feature, it needs to be set while
> > we boot it.
>
> Hi Daniel,
> Yes, this is possible as long you have a quorum block node. The rest
> can be added while running.
>
> > 2)  If primary VM or secondary VM broke, could we start the third VM
> > to keep fault tolerance feature?
>
> I'm currently working on this, see my latest PATCH series here:
>
> https://lore.kernel.org/qemu-devel/cover.1571925699.git.lukasstraub2@web.de/
>
> >
> > Best regard,
> > Daniel Cho.
>
>

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