Hi:
I want to test the performance of different chunk size, so I
create a small raid (about 20G~200G) and use command like "mdadm
--grow -c 64 /dev/md2) to change the chunk size.
after changing chunk size, I found almost every time the raid can
not re-assemble after reboot.
the error message shows like "xxx does not have a valid v1.2
superblock, not importing!".
I found I can use "mdadm --assemble --update=devicesize ....." to
correct it. so I just continue my testing.
now testing is done, so I want to grow the small raid to full size,
but I am surprised that the " Used Dev Size" stocked at some stage and
can not grow to full size. maybe I miss some command parameter?
I think I need to re-create the raid. but maybe someone is
interested to see what happened. my environment is rhel 7.3 (but
redhat backport kernel 4.x softwareraid stack to their 3.10 kernel).
I have several testing raidset. below is a 4disk raid6:
==========================================================================================
command "mdadm --detail /dev/md1":
/dev/md1:
Version : 1.2
Creation Time : Mon Jun 5 17:58:52 2017
Raid Level : raid6
Array Size : 4116416128 (3925.72 GiB 4215.21 GB)
Used Dev Size : 2058208064 (1962.86 GiB 2107.61 GB)
Raid Devices : 4
Total Devices : 4
Persistence : Superblock is persistent
Update Time : Wed Jun 21 11:06:32 2017
State : clean
Active Devices : 4
Working Devices : 4
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 64K
Name : localhost.localdomain:pv00
UUID : cc6a6b68:3d066e91:8bac3ba0:96448f78
Events : 8180
Number Major Minor RaidDevice State
0 8 3 0 active sync /dev/sda3
1 8 19 1 active sync /dev/sdb3
5 8 51 2 active sync /dev/sdd3
4 8 35 3 active sync /dev/sdc3
==========================================================================================
==========================================================================================
command "fdisk -lu /dev/sda /dev/sdb /dev/sdc /dev/sdd":
Disk /dev/sda: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 4095 1M BIOS boot parti
2 4096 620543 301M Linux RAID
3 620544 7814037134 3.7T Linux RAID
Disk /dev/sdb: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 4095 1M BIOS boot parti
2 4096 620543 301M Linux RAID
3 620544 7814037134 3.7T Linux RAID
Disk /dev/sdc: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 4095 1M BIOS boot parti
2 4096 620543 301M Linux RAID
3 620544 7814037134 3.7T Linux RAID
Disk /dev/sdd: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 4095 1M BIOS boot parti
2 4096 620543 301M Linux RAID
3 620544 7814037134 3.7T Linux RAID
==========================================================================================
==========================================================================================
command "mdadm --grow --size=max /dev/md1":
mdadm: component size of /dev/md1 unchanged at 2058208064K
==========================================================================================
another raid5 is more strange. it assemble correctly after change
chunk size (this is unusual in my testing environment without
"--update=devicesize").
the strange part is the md2 huge bitmap chunk:
==========================================================================================
command "cat /proc/mdstat"
Personalities : [raid1] [raid6] [raid5] [raid4]
md2 : active raid5 sde1[0] sdf1[1] sdg1[3]
5263812224 blocks super 1.2 level 5, 64k chunk, algorithm 2 [3/3] [UUU]
bitmap: 0/1 pages [0KB], 18014398507384832KB chunk
md0 : active raid1 sdc2[4] sdb2[1] sda2[0] sdd2[5]
308160 blocks super 1.0 [4/4] [UUUU]
bitmap: 0/1 pages [0KB], 65536KB chunk
md1 : active raid6 sdd3[5] sdb3[1] sdc3[4] sda3[0]
4116416128 blocks super 1.2 level 6, 64k chunk, algorithm 2 [4/4] [UUUU]
unused devices: <none>
==========================================================================================
the raid5 device also can not grow to full size:
==========================================================================================
command "mdadm --detail /dev/md2"
/dev/md2:
Version : 1.2
Creation Time : Tue Jun 13 15:21:32 2017
Raid Level : raid5
Array Size : 5263812224 (5019.96 GiB 5390.14 GB)
Used Dev Size : 2631906112 (2509.98 GiB 2695.07 GB)
Raid Devices : 3
Total Devices : 3
Persistence : Superblock is persistent
Intent Bitmap : Internal
Update Time : Wed Jun 21 10:45:39 2017
State : clean
Active Devices : 3
Working Devices : 3
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 64K
Name : love-1:3 (local to host love-1)
UUID : 5b2c25fc:b4ccc860:ba8685fe:5e0433f7
Events : 5176
Number Major Minor RaidDevice State
0 8 65 0 active sync /dev/sde1
1 8 81 1 active sync /dev/sdf1
3 8 97 2 active sync /dev/sdg1
==========================================================================================
==========================================================================================
command "fdisk -lu /dev/sde /dev/sdf /dev/sdg":
Disk /dev/sde: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 7814037134 3.7T Linux RAID
Disk /dev/sdf: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 7814037134 3.7T Linux RAID
Disk /dev/sdg: 4000.8 GB, 4000787030016 bytes, 7814037168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk label type: gpt
# Start End Size Type Name
1 2048 7814037134 3.7T Linux RAID
==========================================================================================
==========================================================================================
command "mdadm --grow --size=max /dev/md2"
mdadm: component size of /dev/md2 unchanged at 2631906112K
==========================================================================================
--
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
