From: Peter Lieven <p...@kamp.de> depending on the target the opt_unmap_gran might be as low as 4K. As we know use this also as a knob to activate the allocationmap feature lower the barrier. The limit 4K (and not 512) is choosen to avoid a potentially too big allocationmap.
Signed-off-by: Peter Lieven <p...@kamp.de> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- block/iscsi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/iscsi.c b/block/iscsi.c index e8d26bb..84bedfa 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -1386,7 +1386,7 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags, /* Guess the internal cluster (page) size of the iscsi target by the means * of opt_unmap_gran. Transfer the unmap granularity only if it has a * reasonable size */ - if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 64 * 1024 && + if (iscsilun->bl.opt_unmap_gran * iscsilun->block_size >= 4 * 1024 && iscsilun->bl.opt_unmap_gran * iscsilun->block_size <= 16 * 1024 * 1024) { iscsilun->cluster_sectors = (iscsilun->bl.opt_unmap_gran * iscsilun->block_size) >> BDRV_SECTOR_BITS; -- 1.8.3.1