On 2021/04/14 23:11, Karel Zak wrote:
> On Wed, Apr 14, 2021 at 10:33:36AM +0900, Naohiro Aota wrote:
>> This series implements probing and wiping of the superblock of zoned btrfs.
>
> I have no disk with zones support, but it seems scsi_debug supports
> it. Do you have any step by step example how to test with btrfs? If
> yes, I will add a test to our test suite.
Yes, scsi_debug does support emulating a ZBC disk. You can setup a disk like this:
modprobe scsi_debug \
max_luns=1 \
sector_size=4096 \
zbc=host-managed \
dev_size_mb=2048 \
zone_size_mb=64 \
zone_nr_conv=0
This will create a 2GB capacity disk with 64 MB zones.
Another solution, may be simpler, is to use null_blk. I am attaching a script
that I use to create zoned null block devices.
# nullblk-create.sh --help
Usage: nullblk-create.sh [options]
Options:
-h | --help : Display this help message and exit
-v : Be verbose (display final config)
-cap <size (GB)> : set device capacity (default: 8)
For zoned devices, capacity is determined
with zone size and total number of zones
-bs <size (B)> : set sector size (default: 512)
-m : enable memory backing (default: false)
-z : create a zoned device (default: false)
-qm <mode> : set queue mode (default: 2)
0=bio, 1=rq, 2=multiqueue
-sq <num> : set number of submission queues
(default: nproc)
-qd <depth> : set queue depth (default: 64)
-im <mode> : set IRQ mode (default: 0)
0=none, 1=softirq, 2=timer
-c <nsecs> : set completion time for timer completion
(default: 10000 ns)
Options for zoned devices:
-zs <size (MB)> : set zone size (default: 8 MB)
-zc <size (MB)> : set zone capacity (default: zone size)
-znc <num> : set number of conv zones (default: 0)
-zns <num> : set number of swr zones (default: 8)
-zr : add a smaller runt swr zone (default: none)
-zmo <num> : set max open zones (default: no limit)
-zma <num> : set max active zones (default: no limit)
Something like this:
# nullblk-create.sh -m -cap 2 -z -zs 64 -znc 0
Created /dev/nullb0
Will also create a 2GB capacity disk with memory backing and 64 MB zones.
For the correct setup of the drive to test btrfs, I will let Naohiro and
Johannes comment.
--
Damien Le Moal
Western Digital Research
Attachment:
nullblk-create.sh
Description: nullblk-create.sh
