this is rather implicitly to Veeam, but perhaps someone has some experience to share. I'm still doing some tests to find an optimal setup. Got a Synology RS1619xs+ system with twin 1Gbe links that I will use as an iSCSI target from a Debian 11.x box using XFS/reflink for fast clones.
On the synology box assuming one creates a btrfs volume that will host the iscsi lun there are two choices to do the latter (iscsi lun that is): either use thick provisioning or use thin. Synology touts the former to be more robust (definitely ease) as well as having better performance compared to the latter. However I made a couple of very simplr tests (single-path iscsi, nothing fancy) from my Debian box testing both thick and thin and in all cases thin provisioning was faster (/dev/sdb is a 100Gb thick provisioned volume, formatted to xfs 4k clusters/reflink on/crc on, whereas /dev/sdc is the same albeit with thin provisioning):
Code: Select all
# ls ~user/
Win10_x64_grk_build1709.iso Win10_x64_grk_build1909.iso
root@veeam-repo1:/etc# time cp !$/Win10_x64_grk_build1709.iso /mnt/sdb
time cp ~user//Win10_x64_grk_build1709.iso /mnt/sdb
real 0m33.485s
user 0m0.059s
sys 0m8.423s
root@veeam-repo1:/etc# time cp ~user//Win10_x64_grk_build1709.iso /mnt/sdc
real 0m27.833s
user 0m0.024s
sys 0m7.458s
root@veeam-repo1:/etc# time cp ~user//Win10_x64_grk_build1909.iso /mnt/sdc
real 0m32.714s
user 0m0.060s
sys 0m8.180s
root@veeam-repo1:/etc# time cp ~user//Win10_x64_grk_build1909.iso /mnt/sdb
real 0m48.300s
user 0m0.049s
sys 0m10.612s
root@veeam-repo1:/etc# time md5sum /mnt/sdb/*
21f0d448b19d07e5a04da7d4a3fcc6f2 /mnt/sdb/Win10_x64_grk_build1709.iso
3f217e9c6c15004446566b52a05b6676 /mnt/sdb/Win10_x64_grk_build1909.iso
real 1m9.974s
user 0m25.890s
sys 0m7.101s
root@veeam-repo1:/etc# time md5sum /mnt/sdc/*
21f0d448b19d07e5a04da7d4a3fcc6f2 /mnt/sdc/Win10_x64_grk_build1709.iso
3f217e9c6c15004446566b52a05b6676 /mnt/sdc/Win10_x64_grk_build1909.iso
real 1m8.700s
user 0m25.647s
sys 0m7.337s