Resize md4

Re: Resize md4

Fri, 02 Jun 2023 22:12:11 +0000

Many years later, used this post as a springboard to upgrade my WD MyCloud from 2TB RAID1 drives to new 10TB drives while online and without losing any data. Including my steps here for posterity.

Complete full backup to external drive - not a member of the RAID array.
Remove #2 drive
Install new #2 drive
Boot up, perform recovery to build out partition table

#remove new #2 drive from raid group
mdadm /dev/md1 —fail /dev/sdb2 —remove /dev/sdb2

#use gdisk to resize partitions - data partition should contain all of the free space.
#use blkid to collect current partition guids - after creating new partitions, set GUID to old guid to keep alignment
gdisk /dev/sdb

Disk /dev/sdb: 19532873728 sectors, 9.1 TiB
Model: WDC WD101EFBX-68
Sector size (logical/physical): 512/4096 bytes
Disk identifier (GUID): A226A521-E027-4398-84CC-028A914481C4
Partition table holds up to 128 entries
Main partition table begins at sector 2 and ends at sector 33
First usable sector is 34, last usable sector is 19532873694
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number Start (sector) End (sector) Size Code Name
1 2048 4196351 2.0 GiB 8200 Linux swap
2 6293504 3904931839 1.8 TiB 0700 Microsoft basic data
3 3904931840 19532873694 7.3 TiB 0700 Microsoft basic data
4 4196352 6293503 1024.0 MiB 0700 Microsoft basic data

/dev/sdb3: PARTLABEL="Microsoft basic data" PARTUUID="0cf82435-1432-400c-83df-3a84f9c0536a"
/dev/sdb2: UUID="f4e48f8e-e3c2-9419-d836-30a7bd1c092d" UUID_SUB="a2314c53-f14e-d48e-51c6-8c5a0b0e13c8" LABEL="1" TYPE="linux_raid_member" PARTLABEL="Microsoft basic data" PARTUUID="0b9b4fe0-e36b-40cc-ab68-c96a821fe8de"

#Delete partition #3, create new partition with new start/end values
#Set partition guid to same as collected from blkid earlier

19532873694 - 2097151 = 19530776543

sdb3
Start: 19530776543
End: 19532873694

#Delete partition #2, create new partition with new start/end values
#Set partition guid to same as collected from blkid earlier

sdb2
Start: 6293504
End: 19530774527

reboot

#recreate the md1 array
mdadm —add /dev/md1 /dev/sdb2

#Replace #1 drive, wait for rebuild to complete

#grow array - disable bitmap first, update size, then re-enable bitmap
mdadm —grow /dev/md1 —bitmap none
mdadm —grow /dev/md1 —size max
mdadm —wait /dev/md1
mdadm —grow /dev/md1 —bitmap internal

#kill processes using md1 (disconnect from web console first)

use kill and the pid reported by fuser to kill all the processes

fuser -vm /dev/md1

#unmount md1 (try a couple times after killing as it will report busy)
umount /dev/md1

#filesystem check
e2fsck -f /dev/md1

#resize filesystem
resize2fs /dev/md1

#remount, check and see if expected files are still there :)
mount /dev/md1 /mnt/HD/HD_a2

#reboot
reboot

Re: Resize md4

Mon, 08 Aug 2016 01:03:11 +0000

Thank you, JpgOrganizer, for teaching me the "cat /proc/mdstat" command. I have a box that is taking forever to rebuild after a disk failure, and you taught me that I have been foolish in giving up and trying again after a few days. Through your wisdom, I have learned that the process is indeed moving forward, albeit at glacial speed.

Thanks again.

Re: Resize md4

Wed, 11 Nov 2015 18:24:11 +0000

Hi,
I did the same a few years ago.
To write a documentation I copied all my commands to a text file, together with some notes. Perhaps not all used commands have been necessary.
But I never wrote the documentation :-(

But maybe that file helps you a bit.
I did the complete process with the discs within MyBook (Blue ring) and all data kept available. But I had an additional disc with a backup laying aside.

I started with a working pair 1TB discs in raid1 mode, but just 500GB have been used at this time.

[root@MyBook /]# cat /proc/mdstat Personalities : [linear] [raid1] md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] md4 : active raid1 sda4[0] sdb4[1] 484327552 blocks [2/2] [UU] unused devices:  [root@MyBook /]# -------------- [root@MyBook /]# mdadm /dev/md4 --fail /dev/sda4 --remove /dev/sda4 mdadm: set /dev/sda4 faulty in /dev/md4 mdadm: hot removed /dev/sda4 [root@MyBook /]# --------------- [root@MyBook /]# cat /proc/mdstat Personalities : [linear] [raid1] md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] md4 : active raid1 sdb4[1] 484327552 blocks [2/1] [_U] unused devices:  [root@MyBook /]# -------------- [root@MyBook /]# fdisk /dev/sda The number of cylinders for this disk is set to 121601. There is nothing wrong with that, but this is larger than 1024, and could in certain setups cause problems with: 1) software that runs at boot time (e.g., old versions of LILO) 2) booting and partitioning software from other OSs (e.g., DOS FDISK, OS/2 FDISK) Command (m for help): p Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 4 369 2939895 fd Linux raid autodetect /dev/sda2 370 382 104422+ fd Linux raid autodetect /dev/sda3 383 505 987997+ fd Linux raid autodetect /dev/sda4 506 60801 484327620 fd Linux raid autodetect Command (m for help): d Partition number (1-4): 4 Command (m for help): p Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 4 369 2939895 fd Linux raid autodetect /dev/sda2 370 382 104422+ fd Linux raid autodetect /dev/sda3 383 505 987997+ fd Linux raid autodetect Command (m for help): n Command action e extended p primary partition (1-4) p Selected partition 4 First cylinder (1-121601, default 1): 506 Last cylinder or +size or +sizeM or +sizeK (506-121601, default 121601): Using default value 121601 Command (m for help): p Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 4 369 2939895 fd Linux raid autodetect /dev/sda2 370 382 104422+ fd Linux raid autodetect /dev/sda3 383 505 987997+ fd Linux raid autodetect /dev/sda4 506 121601 972703620 83 Linux Command (m for help): t Partition number (1-4): 4 Hex code (type L to list codes): fd Changed system type of partition 4 to fd (Linux raid autodetect) Command (m for help): p Disk /dev/sda: 1000.2 GB, 1000204886016 bytes 255 heads, 63 sectors/track, 121601 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/sda1 4 369 2939895 fd Linux raid autodetect /dev/sda2 370 382 104422+ fd Linux raid autodetect /dev/sda3 383 505 987997+ fd Linux raid autodetect /dev/sda4 506 121601 972703620 fd Linux raid autodetect Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. WARNING: Re-reading the partition table failed with error 16: Device or resource busy. The kernel still uses the old table. The new table will be used at the next reboot. Syncing disks. [root@MyBook /]# cat /proc/mdstat Personalities : [linear] [raid1] md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] md4 : active raid1 sdb4[1] 484327552 blocks [2/1] [_U] unused devices:  [root@MyBook /]# ------------------- [root@MyBook /]# reboot [root@MyBook /]# -------------------- [root@MyBook /]# pwd / -------------------- [root@MyBook /]# cat /proc/mdstat Personalities : [linear] [raid1] md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] md4 : active raid1 sdb4[1] 484327552 blocks [2/1] [_U] unused devices:  -------------------- [root@MyBook /]# mdadm -Cv /dev/md5 -l1 -n2 -c64 /dev/sda4 missing mdadm: chunk size ignored for this level mdadm: /dev/sda4 appears to contain an ext2fs file system size=484327552K mtime=Thu Jan 1 01:00:02 1970 mdadm: size set to 972703552K Continue creating array? y mdadm: array /dev/md5 started. [root@MyBook /]# ----------------------- [root@MyBook /]# mkfs.ext3 /dev/md5 mke2fs 1.38 (30-Jun-2005) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) 121602048 inodes, 243175888 blocks 12158794 blocks (5.00%) reserved for the super user First data block=0 7422 block groups 32768 blocks per group, 32768 fragments per group 16384 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 102400000, 214990848 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 39 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. [root@MyBook /]# ------------------------- [root@MyBook /]# cd /shares [root@MyBook shares]# mkdir itemp [root@MyBook shares]# ls -l total 16 drwxr-xr-x 3 root root 4096 Feb 17 13:35 external drwxr-xr-x 6 root root 4096 Dec 25 2007 internal drwxr-xr-x 2 root root 4096 Feb 17 14:12 itemp [root@MyBook shares]# [root@MyBook /]# mount /dev/md5 /shares/itemp [root@MyBook /]# df -m Filesystem 1M-blocks Used Available Use% Mounted on rootfs 2826 350 2333 14% / /dev/root 2826 350 2333 14% / /dev/md3 950 56 847 7% /var /dev/md4 465554 363311 102244 79% /shares/internal /dev/ram1 1 1 1 76% /mnt/ramdisk /dev/sdc2 938899 611953 279253 69% /shares/external/WD-Ext-HDD-1021/Partition-2 /dev/md5 935000 129 887377 1% /shares/itemp [root@MyBook /]# [root@MyBook /]# cd /shares/itemp/ [root@MyBook itemp]# mkdir DATEN [root@MyBook itemp]# chown www-data DATEN/ [root@MyBook itemp]# ls -l total 20 drwxr-xr-x 2 www-data root 4096 Feb 17 14:14 DATEN drwx------ 2 root root 16384 Feb 17 14:07 lost+found [root@MyBook itemp]# chmod 700 DATEN/ [root@MyBook itemp]# ls -l total 20 drwx------ 2 www-data root 4096 Feb 17 14:14 DATEN drwx------ 2 root root 16384 Feb 17 14:07 lost+found [root@MyBook itemp]# mkdir PUBLIC [root@MyBook itemp]# chmod 775 PUBLIC/ [root@MyBook itemp]# chgrp www-data PUBLIC/ [root@MyBook itemp]# ls -l total 24 drwx------ 2 www-data root 4096 Feb 17 14:14 DATEN drwxrwxr-x 2 root www-data 4096 Feb 17 14:15 PUBLIC drwx------ 2 root root 16384 Feb 17 14:07 lost+found [root@MyBook itemp]# ------------------- [root@MyBook itemp]# rsync -av /shares/internal/DATEN/ /shares/itemp/DATEN/ building file list ... done sent 382888448200 bytes received 7620424 bytes 1940881.18 bytes/sec total size is 382817487214 speedup is 1.00 [root@MyBook DATEN]# d ---------------------- [root@MyBook /]# cat /etc/mdadm.conf DEVICE partitions ARRAY /dev/md1 level=raid1 num-devices=2 UUID=100744ac:8daed8d8:e33c8903:2a1dd289 ARRAY /dev/md2 level=raid1 num-devices=2 UUID=3ba0da27:8c1dbe15:d50ede47:9da0719e ARRAY /dev/md3 level=raid1 num-devices=2 UUID=6033e7ea:335bedb8:a0355b94:c2da9ea1 ARRAY /dev/md4 level=raid1 num-devices=2 UUID=11ade3f7:a3080af4:5d4fc72b:d1d68bad [root@MyBook /]# ------------------ [root@MyBook /]# mdadm --detail --scan ARRAY /dev/md4 level=raid1 num-devices=2 UUID=11ade3f7:a3080af4:5d4fc72b:d1d68bad ARRAY /dev/md3 level=raid1 num-devices=2 UUID=6033e7ea:335bedb8:a0355b94:c2da9ea1 ARRAY /dev/md2 level=raid1 num-devices=2 UUID=3ba0da27:8c1dbe15:d50ede47:9da0719e ARRAY /dev/md1 level=raid1 num-devices=2 UUID=100744ac:8daed8d8:e33c8903:2a1dd289 ARRAY /dev/md5 level=raid1 num-devices=2 UUID=ce783a0a:2bdf50fc:4cc4c6b2:84711516 -------------- [root@MyBook /]# umount /dev/md4 [root@MyBook /]# mdadm --stop /dev/md4 [root@MyBook /]# ----------------- [root@MyBook /]# cd / ------------------- [root@MyBook /]# umount /dev/md5 [root@MyBook /]# mdadm --stop /dev/md5 [root@MyBook /]# ----------------- [root@MyBook /]# mdadm --assemble /dev/md4 /dev/sda4 mdadm: /dev/md4 has been started with 1 drive (out of 2). [root@MyBook /]# mdadm --detail --scan ARRAY /dev/md4 level=raid1 num-devices=2 UUID=ce783a0a:2bdf50fc:4cc4c6b2:84711516 ARRAY /dev/md3 level=raid1 num-devices=2 UUID=6033e7ea:335bedb8:a0355b94:c2da9ea1 ARRAY /dev/md2 level=raid1 num-devices=2 UUID=3ba0da27:8c1dbe15:d50ede47:9da0719e ARRAY /dev/md1 level=raid1 num-devices=2 UUID=100744ac:8daed8d8:e33c8903:2a1dd289 [root@MyBook /]# cat /proc/mdstat Personalities : [linear] [raid1] md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] md4 : active raid1 sda4[0] 972703552 blocks [2/1] [U_] unused devices:  [root@MyBook /]# ------------------------------ [root@MyBook /]# mount /dev/md4 /shares/internal [root@MyBook /]# df -m Filesystem 1M-blocks Used Available Use% Mounted on rootfs 2826 350 2333 14% / /dev/root 2826 350 2333 14% / /dev/md3 950 56 847 7% /var /dev/ram1 1 1 1 76% /mnt/ramdisk /dev/sdc2 938899 611953 279253 69% /shares/external/WD-Ext-HDD-1021/Partition-2 /dev/md4 935000 367101 520404 42% /shares/internal [root@MyBook /]# ---------------------------- [root@MyBook /]# mdadm --detail --scan >/etc/mdadm.conf ------------------------------ [root@MyBook /]# cat /etc/mdadm.conf DEVICE partitions ARRAY /dev/md1 level=raid1 num-devices=2 UUID=100744ac:8daed8d8:e33c8903:2a1dd289 ARRAY /dev/md2 level=raid1 num-devices=2 UUID=3ba0da27:8c1dbe15:d50ede47:9da0719e ARRAY /dev/md3 level=raid1 num-devices=2 UUID=6033e7ea:335bedb8:a0355b94:c2da9ea1 ARRAY /dev/md4 level=raid1 num-devices=2 UUID=ce783a0a:2bdf50fc:4cc4c6b2:84711516 [root@MyBook /]# ------------ [root@MyBook /]# mdadm -Cv /dev/md4 -l1 -n2 -c64 /dev/sda4 missing mdadm: chunk size ignored for this level mdadm: /dev/sda4 appears to contain an ext2fs file system size=972703552K mtime=Tue Feb 19 21:40:52 2013 mdadm: /dev/sda4 appears to be part of a raid array: level=raid1 devices=2 ctime=Sun Feb 17 13:44:08 2013 mdadm: size set to 972703552K Continue creating array? y mdadm: array /dev/md4 started. [root@MyBook /]# mdadm --detail /dev/md4 ---------------------- [root@MyBook /]# mdadm --examine /dev/sda4 --------------------- [root@MyBook /]# mdadm --detail --scan >/etc/mdadm.conf ------------------------------ ====================== alte /dev/sdb4 aus md4 rausnehmen mit mdadm -- stop /dev/md4 [root@MyBook /]# mdadm --assemble /dev/md4 /dev/sda4 mdadm: /dev/md4 has been started with 1 drive (out of 2). [root@MyBook /]# mdadm --detail --scan ARRAY /dev/md3 level=raid1 num-devices=2 UUID=6033e7ea:335bedb8:a0355b94:c2da9ea1 ARRAY /dev/md2 level=raid1 num-devices=2 UUID=3ba0da27:8c1dbe15:d50ede47:9da0719e ARRAY /dev/md1 level=raid1 num-devices=2 UUID=100744ac:8daed8d8:e33c8903:2a1dd289 ARRAY /dev/md4 level=raid1 num-devices=2 UUID=e1bac256:ab686870:f7ccf0bc:0cd378d4 [root@MyBook /]# neue UUID ins /etc/mdadm.conf eintragen reboot [root@MyBook /]# mdadm --detail /dev/md4 /dev/md4: Version : 00.90.03 Creation Time : Tue Feb 19 23:03:47 2013 Raid Level : raid1 Array Size : 972703552 (927.64 GiB 996.05 GB) Device Size : 972703552 (927.64 GiB 996.05 GB) Raid Devices : 2 Total Devices : 1 Preferred Minor : 4 Persistence : Superblock is persistent Update Time : Thu Jan 1 01:00:02 1970 State : clean, degraded Active Devices : 1 Working Devices : 1 Failed Devices : 0 Spare Devices : 0 UUID : e1bac256:ab686870:f7ccf0bc:0cd378d4 Events : 0.3 Number Major Minor RaidDevice State 0 8 4 0 active sync /dev/sda4 1 0 0 1 removed [root@MyBook /]# ----- mdadm -a /dev/md4 /dev/sdb4 -------------- [root@MyBook ny]# cat /proc/mdstat Personalities : [linear] [raid1] md4 : active raid1 sdb4[1] sda4[0] 972703552 blocks [2/1] [U_] [>....................] recovery = 0.2% (2906688/972703552) finish=576.6min speed=28028K/sec md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] unused devices:  [root@MyBook ny]# [root@MyBook ny]# cat /proc/mdstat Personalities : [linear] [raid1] md4 : active raid1 sdb4[1] sda4[0] 972703552 blocks [2/1] [U_] [================>....] recovery = 80.7% (785757888/972703552) finish=118.9min speed=26200K/sec md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] unused devices:  [root@MyBook ny]# ----------------------------------------------------- [root@MyBook]# cat /proc/mdstat Personalities : [linear] [raid1] md4 : active raid1 sdb4[1] sda4[0] 972703552 blocks [2/2] [UU] md1 : active raid1 sdb1[1] sda1[0] 2939776 blocks [2/2] [UU] md2 : active raid1 sdb2[1] sda2[0] 104320 blocks [2/2] [UU] md3 : active raid1 sdb3[1] sda3[0] 987904 blocks [2/2] [UU] unused devices:  [root@MyBook]#

Re: Resize md4

Thu, 29 Oct 2015 08:56:49 +0000

I tried the following commands by connecting the hdd using an usb external rack to laptop (live cd ubuntu netbook remix), but after the WD BlueRings 2 would not start. I believe the partition somehow is no longer part of the raid :
~# parted
~#(parted) unit s
~#(parted) rm 4
~#(parted) mkpart primary ##start -1
~#(parted) quit
~# sync
~# e2fsck -f /dev/sda4
~# resize2fs -p /dev/sda4
~# sync

After this I used one of the old hdd's to resync and tried GParted to resize the partition (I believe grow was the command that I saw in advanced details). The result is the same: the partition is no longer part of the raid and blue rings will not start.

Anybody that can help ?

Re: Resize md4

Wed, 28 Oct 2015 08:13:22 +0000

I tried some, but could not get it done without pulling the disks out.
And, if I get them out, and resize using a live cd linux OS, how can I do it without loosing data? I could not find a step by step tutorial, and I'm not veri familiar with linux
Thanks

Re: Resize md4

Tue, 27 Oct 2015 15:13:59 +0000

you need to resize the data partition. lots of info on this site or the the forum about the steps. probably best if you pulled the disks and did it using a linux OS.

Resize md4

Tue, 27 Oct 2015 14:26:35 +0000

Hi,
I have a WD Blue Rings 2 and upgraded hdd from 500 gb to 1 tb one by one: replaced one old with a new one and waited to sync, and after replaced the second old with a new one and as well waited to sync.
I would have expected that the md4 raid1 partition would increase to use all available space, but did not.

Any way to resize it without unpluging hdd and connecting it to a ?
I must mention that I have ssh access to the device.