Lidong, tests need to happen under heavy load, i.e. worst case scenario failures. E.g. an fs is mounted and being updated whilst you're tacking offline/bringing back mirror legs to cause them to be get resynchronized. Heinz On 04/16/2015 05:43 AM, Lidong Zhong wrote:
Hi List/Heinz, These three patches are done based on last patch series that replied on April 8. The following is the test I did about this feature. My test environment: linux-klqg:~ # dmsetup ls --tree vg-lv (253:4) ├─vg-lv_mimage_2 (253:3) │ └─ (8:48) ├─vg-lv_mimage_1 (253:2) │ └─ (8:32) ├─vg-lv_mimage_0 (253:1) │ └─ (8:16) └─vg-lv_mlog (253:0) └─ (8:64) nux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 600/600 1 AAA 3 disk 253:0 A vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear linux-klqg:~ # dmsetup table vg-lv_mimage_2: 0 614400 linear 8:48 2048 vg-lv: 0 614400 mirror disk 2 253:0 1024 3 253:1 0 253:2 0 253:3 0 2 handle_errors keep_log vg-lv_mimage_1: 0 614400 linear 8:32 2048 vg-lv_mimage_0: 0 614400 linear 8:16 2048 vg-lv_mlog: 0 8192 linear 8:64 2048 1\, single data device failure After make one of the data legs failed, writing data to the first three regions. linux-klqg:~ # echo "a" |dd of=/dev/vg/lv bs=1K count=1 seek=0 0+1 records in 0+1 records out 2 bytes (2 B) copied, 0.0103211 s, 0.2 kB/s linux-klqg:~ # echo "b" |dd of=/dev/vg/lv bs=1K count=1 seek=512 0+1 records in 0+1 records out 2 bytes (2 B) copied, 0.00428962 s, 0.5 kB/s linux-klqg:~ # echo "c" |dd of=/dev/vg/lv bs=1K count=1 seek=1024 0+1 records in 0+1 records out 2 bytes (2 B) copied, 0.00282482 s, 0.7 kB/s linux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 597/600 1 ADA 3 disk 253:0 A vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear Now the failed device comes back, its major/minor number may changes, replace the table as needed. (The devices I tested on are iscsi devices and the minor number changed after each attach/detach) Then start the recovery linux-klqg:~ # dmsetup suspend vg-lv linux-klqg:~ # dmsetup resume vg-lv linux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 600/600 1 AAA 3 disk 253:0 A vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear We can see that all the regions are in sync now. 2\, two or more data device failure After detaching the first device(mine is /dev/sdb), write data to the first and second region linux-klqg:~ # echo "1111111" | dd of=/dev/vg/lv bs=1K count=1 seek=0 0+1 records in 0+1 records out 8 bytes (8 B) copied, 0.00209451 s, 3.8 kB/s linux-klqg:~ # echo "222222" | dd of=/dev/vg/lv bs=1K count=1 seek=512 0+1 records in 0+1 records out 7 bytes (7 B) copied, 0.00259999 s, 2.7 kB/s linux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 598/600 1 ADA 3 disk 253:0 A vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear Now the first and second region are marked as no sync. Then detach the second device (mine is /dev/sdd) and write data to the third and fourth region linux-klqg:~ # echo "333333" | dd of=/dev/vg/lv bs=1K count=1 seek=1024 0+1 records in 0+1 records out 7 bytes (7 B) copied, 0.00178031 s, 3.9 kB/s linux-klqg:~ # echo "444444" | dd of=/dev/vg/lv bs=1K count=1 seek=1536 0+1 records in 0+1 records out 7 bytes (7 B) copied, 0.00256491 s, 2.7 kB/s linux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 596/600 1 DDA 3 disk 253:0 A vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear Now there are 4 regions are marked as no sync. Then the first failed device comes back, we try to do the recovery. linux-klqg:~ # dmsetup suspend vg-lv linux-klqg:~ # dmsetup resume vg-lv linux-klqg:~ # linux-klqg:~ # linux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 596/600 1 DDA 3 disk 253:0 A vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear And it shows there are still 4 regions are marked as no resync, because there is still a missing device. And we keep writing to the fifth region linux-klqg:~ # echo "5555555" | dd of=/dev/vg/lv bs=1K count=1 seek=2048 0+1 records in 0+1 records out 8 bytes (8 B) copied, 0.00213449 s, 3.7 kB/s And now the second missing device comes back. We try to do the recovery linux-klqg:~ # dmsetup suspend vg-lv linux-klqg:~ # dmsetup resume vg-lv linux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 600/600 1 AAA 3 disk 253:0 A vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear It shows all the legs are sync now. we read data from each leg and get the same result. 3\, log device failure After make the log device failed, we tried to write on this lv linux-klqg:~ # echo "test" |dd of=/dev/vg/lv bs=1K count=1 seek=0 0+1 records in 0+1 records out 21 bytes (21 B) copied, 0.00470523 s, 4.5 kB/s linux-klqg:~ # dmsetup status vg-lv_mimage_2: 0 614400 linear vg-lv: 0 614400 mirror 3 253:1 253:2 253:3 600/600 1 AAA 3 disk 253:0 D vg-lv_mimage_1: 0 614400 linear vg-lv_mimage_0: 0 614400 linear vg-lv_mlog: 0 8192 linear And we can see that the log device is marked as failed. And the bio is not written to the data legs because we can't read new data our of the leg Is the test enough? or is there corner case that is not covered in the patch? Any advice is appreciated. Regards, Lidong Lidong Zhong (3): dm-raid1: fix the parameter passed into the kernel dm-raid1: remove the error flags in the mirror set when it's in sync dm-raid1: change default mirror when it's not in sync drivers/md/dm-raid1.c | 38 +++++++++++++++++++++++++------------- 1 file changed, 25 insertions(+), 13 deletions(-)
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