Daniel P. Berrangé <berrange@xxxxxxxxxx> wrote:
> On Mon, Jun 12, 2023 at 09:33:44PM +0200, Juan Quintela wrote:
>> Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx>
>> ---
>> docs/about/deprecated.rst | 8 ++++
>> qapi/migration.json | 92 ++++++++++++++++++++++++---------------
>> migration/options.c | 13 ++++++
>> 3 files changed, 79 insertions(+), 34 deletions(-)
>>
>> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
>> index 173c5ba5cb..fe7f2bbde8 100644
>> --- a/docs/about/deprecated.rst
>> +++ b/docs/about/deprecated.rst
>> @@ -460,3 +460,11 @@ block migration (since 8.1)
>> Block migration is too inflexible. It needs to migrate all block
>> devices or none. Use driver_mirror+NBD instead.
>>
>> +old compression method (since 8.1)
>> +''''''''''''''''''''''''''''''''''
>> +
>> +Compression method fails too much. Too many races. We are going to
>> +remove it if nobody fixes it. For starters, migration-test
>> +compression tests are disabled becase they hand randomly. If you need
>> +compression, use multifd compression methods.
>> +
>> diff --git a/qapi/migration.json b/qapi/migration.json
>> index a8497de48d..40a8b5d124 100644
>> --- a/qapi/migration.json
>> +++ b/qapi/migration.json
>> @@ -244,6 +244,7 @@
>> #
>> # @compression: migration compression statistics, only returned if
>> # compression feature is on and status is 'active' or 'completed'
>> +# It is obsolete and deprecated. Use multifd compression methods.
>> # (Since 3.1)
>
> This doesn't give users an indication /why/ we're saying this. Instead
> I'd suggest
>
> This feature is unreliable and not tested. It is recommended to
> use multifd migration instead, which offers an alternative reliable
> and tested compression implementation.
Much better. Done, thanks.
>> # @deprecated: @disk migration is deprecated. Use driver_mirror+NBD
>> -# instead.
>> +# instead. @compression is obsolete use multifd compression
>> +# methods instead.
>
> For @deprecated, are we supposed to list multiple things at once, or
> use a separate @deprecated tag for each one ?
# @unstable: Members @x-colo and @x-ignore-shared are experimental.
This is the only example that I found that is similar.
Only one example. Markus?
>
> Again I'd suggest rewording
>
> @compression is unreliable and untested. It is recommended to
> use multifd migration, which offers an alternative compression
> implementation that is reliable and tested.
Done.
>> @@ -443,6 +443,11 @@ bool migrate_caps_check(bool *old_caps, bool *new_caps, Error **errp)
>> "Use driver_mirror+NBD instead.");
>> }
>>
>> + if (new_caps[MIGRATION_CAPABILITY_BLOCK]) {
>
> Surely MIGRATION_CAPABILITY_COMPRESS not BLOCK ?
Good catch. Copy & paste to its best.
Thanks very much.
