As mentioned in the kernel enabling [1] these cache volumes augment the
existing imsm model in that cache legs each imply a container. In the
standard cache configuration two single-drive-raid0 volumes (from
separate containers) are associated into a cached volume. The diagram
below attempts to make this clearer.
+-----------------------+ +----------------------+
| sda | SSD | sdb | HDD
| +-------------------+ | | +------------------+ |
| | /dev/md/imsm0 | | Container0 | | /dev/md/imsm1 | | Container1
| | +---------------+ | | | | +--------------+ | |
| | | /dev/md/vol0 | | | RAID Volume0 | | | /dev/md/vol1 | | | RAID Volume1
| | | +---------+ | | | | | | +----------+ | | |
| | | |SRT Cache| | | | | | | |SRT Target| | | |
+-+-+--+----+----+--+-+-+ +-+-+-+----+-----+-+-+-+
| |
| |
| HDD Cached by SSD |
| +--------------+ |
+-----------+ /dev/md/isrt +----------+
+--------------+
In support of the standard mdadm volume discovery model a uuid a
synthesized from the combination of the two container-family-numbers and
immutable volume-ids. Examine_brief is modified to aggregate cache legs
across containers.
Create support is not included, but existing volumes can be
auto-assembled:
mdadm -Ebs > conf
mdadm -Asc conf
To facilitate testing the patches are also available on github, but note
that this branch will rebase according to review feedback.
git://github.com/djbw/mdadm isrt
[1]: http://marc.info/?l=linux-raid&m=139832034826379&w=2
---
Dan Williams (11):
sysfs: fix sysfs_set_array() to accept valid negative array levels
make must_be_container() more selective
Assemble: show the uuid in the verbose case
Assemble: teardown partially assembled arrays
Examine: support for coalescing "cache legs"
imsm: immutable volume id
imsm: cache metadata definitions
imsm: read cache metadata
imsm: examine cache configurations
imsm: assemble cache volumes
imsm: support cache enabled arrays
Assemble.c | 27 ++-
Examine.c | 92 +++++++++-
Makefile | 2
isrt-intel.h | 270 ++++++++++++++++++++++++++++++
maps.c | 1
mdadm.h | 4
super-intel.c | 516 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
sysfs.c | 13 +
util.c | 18 +-
9 files changed, 865 insertions(+), 78 deletions(-)
create mode 100644 isrt-intel.h
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
