uncacsci@iotla:~$ mkdir /var/tmp/XFSPLAY uncacsci@iotla:~$ cd /var/tmp/XFSPLAY/ uncacsci@iotla:/var/tmp/XFSPLAY$ ls uncacsci@iotla:/var/tmp/XFSPLAY$ dd if=/dev/zero of=/var/tmp/XFSRAW bs=1G count=8 ................ uncacsci@iotla:/var/tmp/XFSPLAY$ sudo apt install xfsprogs uncacsci@iotla:/var/tmp/XFSPLAY$ mkfs.xfs ./XFSBLK meta-data=./XFSBLK isize=512 agcount=4, agsize=524288 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1, sparse=0, rmapbt=0, reflink=0 data = bsize=4096 blocks=2097152, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=1 log =internal log bsize=4096 blocks=2560, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 uncacsci@iotla:/var/tmp/XFSPLAY$ mkdir XFSMNT uncacsci@iotla:/var/tmp/XFSPLAY$ sudo mount /var/tmp/XFSPLAY/XFSBLK /var/tmp/XFSPLAY/XFSMNT uncacsci@iotla:/var/tmp/XFSPLAY$ df Filesystem 1K-blocks Used Available Use% Mounted on ................ /dev/loop21 8378368 41392 8336976 1% /var/tmp/XFSPLAY/XFSMNT uncacsci@iotla:/var/tmp/XFSPLAY$ sudo chown uncacsci /var/tmp/XFSPLAY/XFSMNT/ uncacsci@iotla:/var/tmp/XFSPLAY$ ls -l total 8388632 -rw-rw-r-- 1 uncacsci uncacsci 8589934592 Nov 9 12:55 XFSBLK drwxr-xr-x 2 uncacsci root 20 Nov 9 12:54 XFSMNT uncacsci@iotla:/var/tmp/XFSPLAY$ sudo xfs_freeze -f /var/tmp/XFSPLAY/XFSMNT uncacsci@iotla:/var/tmp/XFSPLAY$ touch XFSMNT/foo & [1] 11165 uncacsci@iotla:/var/tmp/XFSPLAY$ uncacsci@iotla:/var/tmp/XFSPLAY$ jobs [1]+ Running touch XFSMNT/foo & uncacsci@iotla:/var/tmp/XFSPLAY$ sudo xfs_freeze -u /var/tmp/XFSPLAY/XFSMNT [1]+ Done touch XFSMNT/foo uncacsci@iotla:/var/tmp/XFSPLAY$ sudo xfs_info /var/tmp/XFSPLAY/XFSMNT meta-data=/dev/loop21 isize=512 agcount=4, agsize=524288 blks = sectsz=512 attr=2, projid32bit=1 = crc=1 finobt=1 spinodes=0 rmapbt=0 = reflink=0 data = bsize=4096 blocks=2097152, imaxpct=25 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=1 log =internal bsize=4096 blocks=2560, version=2 = sectsz=512 sunit=0 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 uncacsci@iotla:/var/tmp/XFSPLAY$ dd if=/dev/zero of=/var/tmp/XFSPLAY/XFSMNT/stuff1 bs=1M count=16 16+0 records in 16+0 records out 16777216 bytes (17 MB, 16 MiB) copied, 0.00887424 s, 1.9 GB/s uncacsci@iotla:/var/tmp/XFSPLAY$ sudo xfs_logprint /var/tmp/XFSPLAY/XFSBLK xfs_logprint: data device: 0xffffffffffffffff log device: 0xffffffffffffffff daddr: 8388648 length: 20480 cycle: 1 version: 2 lsn: 1,0 tail_lsn: 1,0 length of Log Record: 512 prev offset: -1 num ops: 1 uuid: 36ebd936-85c2-47f6-9b10-a2d0c782b4de format: little endian linux h_size: 32768 ---------------------------------------------------------------------------- Oper (0): tid: b0c0d0d0 len: 8 clientid: LOG flags: UNMOUNT Unmount filesystem ................................................................ ................................................................ Oper (4): tid: be7fd139 len: 0 clientid: TRANS flags: COMMIT ============================================================================ xfs_logprint: skipped 4059 cleared blocks in range: 39 - 4097 xfs_logprint: skipped 16382 zeroed blocks in range: 4098 - 20479 xfs_logprint: physical end of log ============================================================================ xfs_logprint: logical end of log ============================================================================ uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ dd if=/dev/zero of=/var/tmp/XFSPLAY/XFSMNT/stuff1 bs=1M count=16 16+0 records in 16+0 records out 16777216 bytes (17 MB, 16 MiB) copied, 0.00887424 s, 1.9 GB/s uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ ls -l total 16384 -rw-rw-r-- 1 uncacsci uncacsci 0 Nov 9 13:07 foo -rw-rw-r-- 1 uncacsci uncacsci 16777216 Nov 9 13:17 stuff1 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ xfs_bmap stuff1 stuff1: 0: [0..32767]: 160..32927 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ cp /etc/passwd a uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ cp /etc/passwd b uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ cp /etc/passwd c uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ xfs_bmap a b c a: 0: [0..7]: 72..79 b: 0: [0..7]: 80..87 c: 0: [0..7]: 88..95 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ dd if=/dev/zero of=stuff1 bs=1M count=8 8+0 records in 8+0 records out 8388608 bytes (8.4 MB, 8.0 MiB) copied, 0.00454048 s, 1.8 GB/s uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ ls -l total 8204 -rw-r--r-- 1 uncacsci uncacsci 2798 Nov 9 13:18 a -rw-r--r-- 1 uncacsci uncacsci 2798 Nov 9 13:19 b -rw-r--r-- 1 uncacsci uncacsci 2798 Nov 9 13:19 c -rw-rw-r-- 1 uncacsci uncacsci 0 Nov 9 13:07 foo -rw-rw-r-- 1 uncacsci uncacsci 8388608 Nov 9 13:22 stuff1 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ xfs_bmap stuff1 stuff1: 0: [0..16383]: 160..16543 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ dd if=/dev/zero of=stuff2 bs=1M count=8 8+0 records in 8+0 records out 8388608 bytes (8.4 MB, 8.0 MiB) copied, 0.00364641 s, 2.3 GB/s uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ xfs_bmap stuff* stuff1: 0: [0..16383]: 160..16543 stuff2: 0: [0..16383]: 16544..32927 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ cat stuff2 >>stuff1 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ ls -l total 24588 -rw-r--r-- 1 uncacsci uncacsci 2798 Nov 9 13:18 a ................ uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ xfs_bmap stuff* stuff1: 0: [0..16383]: 160..16543 1: [16384..32767]: 32928..49311 stuff2: 0: [0..16383]: 16544..32927 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ sudo xfs_fsr -v stuff2 stuff2 stuff2 already fully defragmented. uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$ sudo xfs_fsr -v stuff1 stuff1 extents before:2 after:1 DONE stuff1 uncacsci@iotla:/var/tmp/XFSPLAY/XFSMNT$