Out of curiosity; I was wondering why the boot of TrueNAS SCALE 21.08-BETA.1 was slow; then I discovered it rebuilt a soft-raid via mdadm at every boot.
from what I understood it is the SWAP.
So; Why TrueNAS is using mdadm ?
since zfs could do everything mdadm could do
and Why this soft-raid is not define in /etc/mdadm/mdadm.conf
When I installed my system with 1 NVME + 2 SSD of 256GB; the soft-raid was pointing at the 2 SSD
then later I plugged in 2 USB of 1TB for the purpose of testing importing and exporting encrypted zpool and data from TN Scale to my Ubuntu Laptop
and at every boot (on the NT SCALE) it seems to rebuild, or at least seeking for, the soft-raid randomly
and now my mdadm is a mix of 1 SSD and 1 USB (my USB drive was plugged during the last boot)
NOTE: both zpool the SSD one and the USB one as been created via the webui TN interface.
from what I understood it is the SWAP.
So; Why TrueNAS is using mdadm ?
since zfs could do everything mdadm could do
and Why this soft-raid is not define in /etc/mdadm/mdadm.conf
# mdadm.conf
#
# !NB! Run update-initramfs -u after updating this file.
# !NB! This will ensure that initramfs has an uptodate copy.
#
# Please refer to mdadm.conf(5) for information about this file.
#
# by default (built-in), scan all partitions (/proc/partitions) and all
# containers for MD superblocks. alternatively, specify devices to scan, using
# wildcards if desired.
#DEVICE partitions containers
# automatically tag new arrays as belonging to the local system
HOMEHOST <system>
# instruct the monitoring daemon where to send mail alerts
MAILADDR root
# This configuration was auto-generated on Mon, 30 Aug 2021 23:23:38 +0000 by mkconf
#
# !NB! Run update-initramfs -u after updating this file.
# !NB! This will ensure that initramfs has an uptodate copy.
#
# Please refer to mdadm.conf(5) for information about this file.
#
# by default (built-in), scan all partitions (/proc/partitions) and all
# containers for MD superblocks. alternatively, specify devices to scan, using
# wildcards if desired.
#DEVICE partitions containers
# automatically tag new arrays as belonging to the local system
HOMEHOST <system>
# instruct the monitoring daemon where to send mail alerts
MAILADDR root
# This configuration was auto-generated on Mon, 30 Aug 2021 23:23:38 +0000 by mkconf
When I installed my system with 1 NVME + 2 SSD of 256GB; the soft-raid was pointing at the 2 SSD
then later I plugged in 2 USB of 1TB for the purpose of testing importing and exporting encrypted zpool and data from TN Scale to my Ubuntu Laptop
and at every boot (on the NT SCALE) it seems to rebuild, or at least seeking for, the soft-raid randomly
and now my mdadm is a mix of 1 SSD and 1 USB (my USB drive was plugged during the last boot)
NOTE: both zpool the SSD one and the USB one as been created via the webui TN interface.
Model: ATA Samsung SSD 860 (scsi)
Disk /dev/sda: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 65.5kB 2147MB 2147MB swap
2 2148MB 256GB 254GB zfs
Model: ATA Samsung SSD 860 (scsi)
Disk /dev/sdb: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 65.5kB 2147MB 2147MB swap
2 2148MB 256GB 254GB zfs
Model: WD My Passport 0748 (scsi)
Disk /dev/sdc: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 65.5kB 2147MB 2147MB swap
2 2148MB 1000GB 998GB zfs
Model: Linux device-mapper (crypt) (dm)
Disk /dev/mapper/md127: 2147MB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:
Number Start End Size File system Flags
1 0.00B 2147MB 2147MB linux-swap(v1)
Model: WDC WDS256G1X0C-00ENX0 (nvme)
Disk /dev/nvme0n1: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 20.5kB 1069kB 1049kB bios_grub
2 1069kB 538MB 537MB fat32 boot, esp
4 538MB 17.7GB 17.2GB swap
3 17.7GB 256GB 238GB zfs
Model: Linux Software RAID Array (md)
Disk /dev/md127: 2147MB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags:
Model: Unknown (unknown)
Disk /dev/zd0: 42.9GB
Sector size (logical/physical): 512B/16384B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 106MB 105MB fat32 EFI system partition boot, esp
2 106MB 123MB 16.8MB Microsoft reserved partition msftres
3 123MB 42.4GB 42.3GB ntfs Basic data partition msftdata
4 42.4GB 42.9GB 533MB ntfs hidden, diag
Disk /dev/sda: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 65.5kB 2147MB 2147MB swap
2 2148MB 256GB 254GB zfs
Model: ATA Samsung SSD 860 (scsi)
Disk /dev/sdb: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 65.5kB 2147MB 2147MB swap
2 2148MB 256GB 254GB zfs
Model: WD My Passport 0748 (scsi)
Disk /dev/sdc: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 65.5kB 2147MB 2147MB swap
2 2148MB 1000GB 998GB zfs
Model: Linux device-mapper (crypt) (dm)
Disk /dev/mapper/md127: 2147MB
Sector size (logical/physical): 512B/512B
Partition Table: loop
Disk Flags:
Number Start End Size File system Flags
1 0.00B 2147MB 2147MB linux-swap(v1)
Model: WDC WDS256G1X0C-00ENX0 (nvme)
Disk /dev/nvme0n1: 256GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 20.5kB 1069kB 1049kB bios_grub
2 1069kB 538MB 537MB fat32 boot, esp
4 538MB 17.7GB 17.2GB swap
3 17.7GB 256GB 238GB zfs
Model: Linux Software RAID Array (md)
Disk /dev/md127: 2147MB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags:
Model: Unknown (unknown)
Disk /dev/zd0: 42.9GB
Sector size (logical/physical): 512B/16384B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 106MB 105MB fat32 EFI system partition boot, esp
2 106MB 123MB 16.8MB Microsoft reserved partition msftres
3 123MB 42.4GB 42.3GB ntfs Basic data partition msftdata
4 42.4GB 42.9GB 533MB ntfs hidden, diag