+ $ guestfish -a test1.img -m /dev/sda1 \
+ debug qtrace "/dev/vda on" : \
+ write /hello "hello, world." : \
+ debug qtrace "/dev/vda off"
+ where test1.img was created by the command above.
+
+ This is just the creation of a new file with a small amount of content.
+
+ Within this trace file, the qtrace on/off commands appear as patterns
+ of reads. For on: 2, 21, 15, 2. For off: 2, 15, 21, 2.
+
+- guestfish-lv-ext4-4k.qtr
+
+ $ guestfish \
+ alloc test1.img 40M : \
+ run : \
+ part-disk /dev/vda mbr : \
+ pvcreate /dev/vda : \
+ vgcreate VG /dev/vda : \
+ lvcreate LV VG 32 : \
+ mkfs-opts ext4 /dev/VG/LV blocksize:4096
+
+ Some points to note:
+ * an ext4 filesystem, so it has a journal and extents
+ * 4K block size, so we expect writes to be aligned
+ * located inside an LV, so more realistic
+
+- guestfish-lv-ext4-4k-write-hello.qtr
+
+ $ guestfish -a test1.img -m /dev/VG/LV \
+ debug qtrace "/dev/vda on" : \
+ write /hello "hello, world." : \
+ debug qtrace "/dev/vda off"
+ where test1.img was created by the previous command.