mdadm RAID5: discard operation is not supported?

[Ulli Horlacher]

fstrim auf RAID5 hatte mal funktioniert, aber nun gehts nicht mehr (neurer
Kernel?):

***@juhu:~/bin# fstrim -v /tmp
/tmp: 61.6 GiB (66146664448 bytes) trimmed

***@juhu:~/bin# fstrim -v /local
fstrim: /local: the discard operation is not supported

***@juhu:~/bin# lshd
Device Size Type Label Mountpoint
sda 1490G SCSI:DOS/MBR "NETAPP_X439_TPM3V1T6AMD"
sda1 64G btrfs "tmp" /tmp
sda2 32G Linux
sda3 32G swap "swap1" [swap]
sda4 1362G linux_raid "mux:nts1"
md127 4086G btrfs "local" /local
sdb 1490G SCSI:DOS/MBR "NETAPP_X439_TPM3V1T6AMD"
sdb1 64G btrfs "U18b"
sdb2 32G Linux
sdb3 32G swap "swap2"
sdb4 1362G linux_raid "mux:nts1"
md127 4086G btrfs "local" /local
sdc 1490G SCSI:DOS/MBR "NETAPP_X439_TPM3V1T6AMD"
sdc1 64G btrfs "M21" /
sdc2 32G Linux
sdc3 32G Linux
sdc4 1362G linux_raid "mux:nts1"
md127 4086G btrfs "local" /local
sdd 1490G SCSI:DOS/MBR "NETAPP_X439_TPM3V1T6AMD"
sdd1 64G btrfs "M21b"
sdd2 32G Linux
sdd3 32G Linux
sdd4 1362G linux_raid "mux:nts1"
md127 4086G btrfs "local" /local

***@juhu:~/bin# mdadm -D /dev/md127
/dev/md127:
Version : 1.2
Creation Time : Thu Feb 10 09:38:22 2022
Raid Level : raid5
Array Size : 4285387776 (3.99 TiB 4.39 TB)
Used Dev Size : 1428462592 (1362.29 GiB 1462.75 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Thu May 9 21:24:02 2024
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0

Layout : left-symmetric
Chunk Size : 512K

Consistency Policy : bitmap

Name : mux:nts1
UUID : 74388db3:3c3b30c3:e1295cc5:46f23ff7
Events : 15621

Number Major Minor RaidDevice State
0 8 20 0 active sync /dev/sdb4
1 8 4 1 active sync /dev/sda4
2 8 52 2 active sync /dev/sdd4
4 8 36 3 active sync /dev/sdc4

[Markus Schaaf]

Post by Ulli Horlacher
fstrim auf RAID5 hatte mal funktioniert, aber nun gehts nicht mehr (neurer

https://www.kernel.org/doc/html/latest/admin-guide/device-mapper/dm-raid.html#discard-support

[Ulli Horlacher]

Post by Markus Schaaf

Post by Ulli Horlacher
fstrim auf RAID5 hatte mal funktioniert, aber nun gehts nicht mehr (neurer

https://www.kernel.org/doc/html/latest/admin-guide/device-mapper/dm-raid.html#discard-support

When a block is discarded, some storage devices will return zeroes when
the block is read. These devices set the `discard_zeroes_data' attribute.

Wie fraegt man das ab?