On 4/11/20 2:30 PM, Bob Liu wrote:
On 4/9/20 2:45 PM, Hannes Reinecke wrote:
Hi all,
this patchset adds a new metadata version 2, which brings the following
improvements:
- UUIDs and labels: Adding three more fields to the metadata containing
the dm-zoned device UUID and label, and the device UUID. This allows
for an unique identification of the devices, so that several dm-zoned
sets can coexist and have a persistent identification.
- Extend random zones by an additional regular disk device: A regular
block device can be added together with the zoned block device, providing
additional (emulated) random write zones. With this it's possible to
handle sequential zones only devices; also there will be a speed-up if
the regular block device resides on a fast medium. The regular block device
is placed logically in front of the zoned block device, so that metadata
and mapping tables reside on the regular block device, not the zoned device.
- Tertiary superblock support: In addition to the two existing sets of metadata
another, tertiary, superblock is written to the first block of the zoned
block device. This superblock is for identification only; the generation
number is set to '0' and the block itself it never updated. The additional
metadate like bitmap tables etc are not copied.
To handle this, some changes to the original handling are introduced:
- Zones are now equidistant. Originally, runt zones were ignored, and
not counted when sizing the mapping tables. With the dual device setup
runt zones might occur at the end of the regular block device, making
direct translation between zone number and sector/block number complex.
For metadata version 2 all zones are considered to be of the same size,
and runt zones are simply marked as 'offline' to have them ignored when
allocating a new zone.
- The block number in the superblock is now the global number, and refers to
the location of the superblock relative to the resulting device-mapper
device. Which means that the tertiary superblock contains absolute block
addresses, which needs to be translated to the relative device addresses
to find the referenced block.
There is an accompanying patchset for dm-zoned-tools for writing and checking
this new metadata.
As usual, comments and reviews are welcome.
Changes to v2:
- Kill dmz_id()
- Include reviews from Damien
- Sanitize uuid handling as suggested by John Dorminy
This series looks good to me, feel free to add my
Reviewed-by: Bob Liu <bob.liu@xxxxxxxxxx>
By the way, have you completed the patches for regular device support?
I was considering rebase my previous patches to this series but not sure is it still necessary.
I have combined both patchsets, this one now also included regular
device support. So no need to resend from your side.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
