Re: [PATCH manager] ui: qemu: add detect zeroes disk option

["Lukas Sichert" <l.sichert@proxmox.com>]

On 2026-06-16 15:01, Fabian Grünbichler <f.gruenbichler@proxmox.com> wrote:

> if I am not mistaken, this is a fix for
> https://bugzilla.proxmox.com/show_bug.cgi?id=4503 ?

Yes, I have also corrected this in a v2 already [1], but I forgot to send a
superseded-by. Sorry for the confusion.

[1] https://lore.proxmox.com/all/20260610131827.11092-1-l.sichert@proxmox.com/

>
> On June 8, 2026 10:36 am, Lukas Sichert wrote:
>> When discard is enabled, qemu-server defaults to `detect-zeroes=unmap`.
>> This can have a significant performance impact for zero writes on some
>> setups, while users might still want to keep guest discard/TRIM support
>> enabled.
>> 
>> Allow configuring the option independently so discard can stay enabled
>> while zero detection is disabled. Persist the checkbox state explicitly,
>> as the backend treats an absent value as the default-enabled behavior.
>> 
>> Signed-off-by: Lukas Sichert <l.sichert@proxmox.com>
>> ---
>>  www/manager6/qemu/HDEdit.js | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>> 
>> diff --git a/www/manager6/qemu/HDEdit.js b/www/manager6/qemu/HDEdit.js
>> index 1bb2bfda..d1d1b0fa 100644
>> --- a/www/manager6/qemu/HDEdit.js
>> +++ b/www/manager6/qemu/HDEdit.js
>> @@ -96,6 +96,7 @@ Ext.define('PVE.qemu.HDInputPanel', {
>>          PVE.Utils.propertyStringSet(me.drive, values.readOnly, 'ro', 'on');
>>          PVE.Utils.propertyStringSet(me.drive, values.cache, 'cache');
>>          PVE.Utils.propertyStringSet(me.drive, values.aio, 'aio');
>> +        me.drive.detect_zeroes = values.detect_zeroes ? 1 : 0;
>
> this should probably have a comment why this line is deviating from the
> ones above (to not lose an explicit false value that clashes with the
> implicit true default value of the backend.

Thanks for looking over this. I will fix it in a v3.

>
>>  
>>          ['mbps_rd', 'mbps_wr', 'iops_rd', 'iops_wr'].forEach((name) => {
>>              let burst_name = `${name}_max`;
>> @@ -152,6 +153,7 @@ Ext.define('PVE.qemu.HDInputPanel', {
>>          values.diskformat = drive.format || 'raw';
>>          values.cache = drive.cache || '__default__';
>>          values.discard = drive.discard === 'on';
>> +        values.detect_zeroes = PVE.Parser.parseBoolean(drive.detect_zeroes, 1);
>>          values.ssd = PVE.Parser.parseBoolean(drive.ssd);
>>          values.iothread = PVE.Parser.parseBoolean(drive.iothread);
>>          values.readOnly = PVE.Parser.parseBoolean(drive.ro);
>> @@ -317,6 +319,12 @@ Ext.define('PVE.qemu.HDInputPanel', {
>>                  reference: 'discard',
>>                  name: 'discard',
>>              },
>> +            {
>> +                xtype: 'proxmoxcheckbox',
>> +                fieldLabel: gettext('Detect zeroes'),
>> +                reference: 'detect_zeroes',
>> +                name: 'detect_zeroes',
>> +            },
>>              {
>>                  xtype: 'proxmoxcheckbox',
>>                  name: 'iothread',
>> -- 
>> 2.47.3
>> 
>> 
>> 
>> 
>> 
>>