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Subject: Re: [pve-devel] [PATCH qemu 2/2] fix #7197: add fix to avoid
 misaligned BLKZEROOUT casuing a hard error
To: Proxmox VE development discussion <pve-devel@lists.proxmox.com>,
 Fiona Ebner <f.ebner@proxmox.com>
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 <20260112155940.298273-3-f.ebner@proxmox.com>
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On 12/01/2026 16:59, Fiona Ebner wrote:
> [...]
> +Commit 5634622bcb ("file-posix: allow BLKZEROOUT with -t writeback")
> +enables the BLKZEROOUT ioctl when using 'writeback' cache, regressing
> +certain 'qemu-img convert' invocations, because of a pre-existing
> +issue. Namely, the BLKZEROOUT ioctl might fail with errno EINVAL when
> +the request is shorter than the block size of the block device.
> +Fallback to the bounce buffer, similar to when the ioctl is not
> +supported at all, rather than treating such an error as fatal.
Ping -- this was now also reported in enterprise support.