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Diffstat (limited to 'results/classifier/gemma3:12b/files/1376938')
| -rw-r--r-- | results/classifier/gemma3:12b/files/1376938 | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/results/classifier/gemma3:12b/files/1376938 b/results/classifier/gemma3:12b/files/1376938 new file mode 100644 index 00000000..682550b9 --- /dev/null +++ b/results/classifier/gemma3:12b/files/1376938 @@ -0,0 +1,19 @@ + +detect-zeroes=unmap fails to discard in some cases + +Under certain circumstances, QEMU 2.1.2 fails to discard the underlaying block. The command to start QEMU is: + +qemu-system-x86_64 -machine pc,accel=kvm -m 2G -smp 2 -vga std -usb -usbdevice tablet -drive if=none,id=ff,aio=native,discard=unmap,detect-zeroes=unmap,file=/tmp/test.qcow2 -device virtio-scsi-pci -device scsi-disk,drive=ff -cdrom /media/iso/archlinux-2014.06.01-dual.iso -vnc :1 + +Steps to reproduce: + + 0. qemu-img create -f qcow2 /tmp/test.qcow2 4G + 1. Boot in the guest (Arch Linux x86_64 with Linux 3.14.4) + 2. cat /dev/zero > /dev/sda. Observe a file of 4109M (size measured with `du -m` + 3. cat /dev/zero > /dev/sda + 4. blkdiscard /dev/sda + 5. Observe that test.qcow2 grows larger than 1M (13M in my testing). + +The results are more severe when you write other kind of data in step 2, for instance `base64 /dev/zero > /dev/sda` and then continuing with step 3 and 4 will result in a file of 3642M, after blkdiscard. + +It makes not much of a difference if I create an ext4 filesystem on top of it and use fstrim (or rm). \ No newline at end of file |