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Diffstat (limited to 'results/classifier/105/device/1366')
| -rw-r--r-- | results/classifier/105/device/1366 | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/results/classifier/105/device/1366 b/results/classifier/105/device/1366 new file mode 100644 index 00000000..7a5c0a9a --- /dev/null +++ b/results/classifier/105/device/1366 @@ -0,0 +1,97 @@ +instruction: 0.986 +device: 0.986 +graphic: 0.983 +other: 0.977 +semantic: 0.977 +assembly: 0.977 +socket: 0.975 +vnc: 0.970 +KVM: 0.953 +network: 0.950 +boot: 0.946 +mistranslation: 0.868 + +Data inconsistency on LVM logical volume mounted as partition on ubuntu guest, when the written file's size is equal or greater than 27G. +Description of problem: +On the guest, writing a 27Gib file or larger result in inconsistent file checksum upon subsequent read. +Steps to reproduce: +**On the host** + +0. Create a LVM logical volume on a Linux RAID 1 (with 1 disk only) + +``` + --- Logical volume --- + LV Path /dev/davidahw2-vg4/lv0 + LV Name lv0 + VG Name davidahw2-vg4 + LV UUID 5FbDcl-eSDe-7cXL-22tj-Lg6O-79AL-4Gq7gx + LV Write Access read/write + LV Creation host, time davida-hw2, 2021-12-06 16:45:00 +0800 + LV Status available + # open 1 + LV Size <7.28 TiB + Current LE 1907688 + Segments 1 + Allocation inherit + Read ahead sectors auto + - currently set to 256 + Block device 253:4 + + --- Segments --- + Logical extents 0 to 1907687: + Type linear + Physical volume /dev/md4 + Physical extents 0 to 1907687 +``` + +1. Format the logical volume as ext4 + +``` +mkfs -t ext4 /dev/davidahw2-vg4/lv0 +``` + +2. Create a libvirt x86 64bits Ubuntu 22.04 machine mounting a LVM logical volume + +``` +<controller type='scsi' index='1' model='virtio-scsi'><driver queues='8' iothread='2'/></controller> + + +<disk type='block' device='disk'> + <driver name='qemu' type='raw'/> + <source dev='/dev/davidahw2-vg4/lv0'/> + <target dev='sdd' bus='scsi'/> + <blockio logical_block_size='512' physical_block_size='4096'/> + <address type='drive' controller='1' bus='0' target='1' unit='0'/> +</disk> +``` + + +**On the guest** + +3. Mount libvirt/qemu provided block device /dev/sdd as ext4 partition + +``` +mount /dev/sdd /mnt/test +``` + +4. Write **27G file** or larger **on the guest** causing the **2nd checksum to be different** + +``` +sync; head -c 27G </dev/urandom >myfile; sha256sum myfile; sha256sum myfile +8d3b4b263961d2c510390f99879be89b4b9134dc588139ede75573be1590115b myfile +a8e886b3c39d9b4721e582c5e2ca25c76ff6561750ac6dc7aa7e70404661d1cf myfile <== ERROR: Inconsistent checksum +``` + +5. Write **26G file** or larger **on the guest** and **both checksum are the same** + +``` +sync; head -c 26G </dev/urandom >myfile; sha256sum myfile; sha256sum myfile +598ac5da9b5bfa14d0ee664ae2590e09da772cba64cbc83ec049a656223c9401 myfile +598ac5da9b5bfa14d0ee664ae2590e09da772cba64cbc83ec049a656223c9401 myfile <== CORRECT: Consistent checksum +``` + +**Important**: +- With the VM shutdown, the same commands on the same mounted ext4 partition **on the host** has consistent checksum every time for file sizes from 20G to 40G. +- The disk has no sign of failure (no badblocks reported to the filesystem, MD raid reports a healthy raid setup, smart reports on error) +Additional information: + |