This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision | ||
start [2019/11/26 23:16] Dan Williams |
start [2020/06/12 15:58] (current) Ira Weiny [Filesystems] |
||
---|---|---|---|
Line 431: | Line 431: | ||
$ mkfs.xfs -f -m reflink=0 /dev/pmem0p2 | $ mkfs.xfs -f -m reflink=0 /dev/pmem0p2 | ||
$ mkfs.btrfs -f /dev/pmem0p3 | $ mkfs.btrfs -f /dev/pmem0p3 | ||
- | $ mount -o dax /dev/pmem0p1 /mnt/ext4-pmem0 | + | $ mount [dax_mount_options] /dev/pmem0p1 /mnt/ext4-pmem0 |
- | $ mount -o dax /dev/pmem0p2 /mnt/xfs-pmem0 | + | $ mount [dax_mount_options] /dev/pmem0p2 /mnt/xfs-pmem0 |
$ mount /dev/pmem0p3 /mnt/btrfs-pmem0 | $ mount /dev/pmem0p3 /mnt/btrfs-pmem0 | ||
Line 454: | Line 454: | ||
/dev/pmem0p3 4.3G 17M 4.1G 1% /mnt/btrfs-pmem0 | /dev/pmem0p3 4.3G 17M 4.1G 1% /mnt/btrfs-pmem0 | ||
</code> | </code> | ||
+ | |||
+ | Where **[dax_mount_options]** depends on the kernel support you have and the desired behavior. See [[fs_mount_options|fs_mount_options]] for details. | ||
Check the kernel log to ensure the DAX mount option was honored; mount does not print this information. Example failures: | Check the kernel log to ensure the DAX mount option was honored; mount does not print this information. Example failures: | ||
Line 481: | Line 483: | ||
==== iostats ==== | ==== iostats ==== | ||
---- | ---- | ||
- | iostats are disabled by default due to performance overhead (e.g., 12M IOPS dropping 25% to 9M IOPS). However, they can be enabled in sysfs if desired. | + | iostats are disabled by default due to performance overhead (e.g., 12M IOPS dropping 25% to 9M IOP |
+ | S). However, they can be enabled in sysfs if desired. | ||
As of kernel 4.5, iostats are only collected for the base pmem device, not per-partition. Also, I/Os that go through DAX paths (rw_page, rw_bytes, and direct_access functions) are not counted, so nothing is collected for: | As of kernel 4.5, iostats are only collected for the base pmem device, not per-partition. Also, I/Os that go through DAX paths (rw_page, rw_bytes, and direct_access functions) are not counted, so nothing is collected for: |