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| author | Christian Krinitsin <mail@krinitsin.com> | 2025-05-30 14:51:13 +0000 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-05-30 14:51:13 +0000 |
| commit | 225caa38269323af1bfc2daadff5ec8bd930747f (patch) | |
| tree | e0a5fefde9ee100ba6f32fb36de6707490e4164e /mailinglist/output_launchpad/1811543 | |
| parent | 904141bfb8d5385b75eb3b7afec1dcda89af65a7 (diff) | |
| download | emulator-bug-study-225caa38269323af1bfc2daadff5ec8bd930747f.tar.gz emulator-bug-study-225caa38269323af1bfc2daadff5ec8bd930747f.zip | |
add mailinglist scraper results
Diffstat (limited to 'mailinglist/output_launchpad/1811543')
| -rw-r--r-- | mailinglist/output_launchpad/1811543 | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/mailinglist/output_launchpad/1811543 b/mailinglist/output_launchpad/1811543 new file mode 100644 index 00000000..79a4e344 --- /dev/null +++ b/mailinglist/output_launchpad/1811543 @@ -0,0 +1,81 @@ +virtio-scsi gives improper discard sysfs entries + +Apologies if this is just an inherent part of paravirtualization that should be expected. + +In my host, I have an LVM thin pool with chunk_size 128MB. Within it, I have a thin volume "tmp". In the host: + +# fdisk -l /dev/lvm/tmp +Disk /dev/lvm/tmp: 256 MiB, 268435456 bytes, 524288 sectors +Units: sectors of 1 * 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 4096 bytes +I/O size (minimum/optimal): 262144 bytes / 134217728 bytes +Disklabel type: gpt +Disk identifier: BAE3154E-6E85-F642-8129-BAD7B58B2775 + +Device Start End Sectors Size Type +/dev/lvm/tmp1 2048 524254 522207 255M Linux filesystem + +$ lsblk +... + └─lvm-tmp 254:13 0 256M 0 lvm + └─lvm-tmp1 254:14 0 255M 0 part + +$ cat /sys/dev/block/254:13/discard_alignment +0 +$ cat /sys/dev/block/254:13/queue/discard_granularity +134217728 +$ cat /sys/dev/block/254:13/queue/discard_max_bytes +17179869184 +$ cat /sys/dev/block/254:13/queue/discard_max_hw_bytes +0 +$ cat /sys/dev/block/254:13/queue/discard_zeroes_data +0 + +$ cat /sys/dev/block/254:14/discard_alignment +133169152 +$ cat /sys/dev/block/254:14/queue/discard_granularity +134217728 +$ cat /sys/dev/block/254:14/queue/discard_max_bytes +17179869184 +$ cat /sys/dev/block/254:14/queue/discard_max_hw_bytes +0 +$ cat /sys/dev/block/254:14/queue/discard_zeroes_data +0 + +If this is given to QEMU using virtio-scsi: + + -device virtio-scsi-pci,id=scsi1 \ + -drive driver=raw,node-name=hdb,file=/dev/lvm/tmp,if=none,discard=unmap,id=hd2 \ + -device scsi-hd,drive=hd2,bootindex=1 \ + +Then incorrect values are given: + +$ lsblk +... +sdb 8:16 0 256M 0 disk +└─sdb1 8:17 0 255M 0 part /mnt + +$ cat /sys/dev/block/8:16/discard_alignment +0 +$ cat /sys/dev/block/8:16/queue/discard_granularity +4096 +$ cat /sys/dev/block/8:16/queue/discard_max_bytes +1073741824 +$ cat /sys/dev/block/8:16/queue/discard_max_hw_bytes +1073741824 +$ cat /sys/dev/block/8:16/queue/discard_zeroes_data +0 + +$ cat /sys/dev/block/8:17/discard_alignment +133169152 + +And, there isn't even a /sys/dev/block/8:17/queue direcotry. + + +This is an automated cleanup. This bug report has been moved to QEMU's +new bug tracker on gitlab.com and thus gets marked as 'expired' now. +Please continue with the discussion here: + + https://gitlab.com/qemu-project/qemu/-/issues/161 + + |