#140 Silly values on web status interface during 3GB raid1 resync (overflow?)

[Anonymous]

Originally created by: brian.br...@gmail.com

What steps will reproduce the problem?
1. Make a dual 3GB raid 1.
2. It starts resyncing.
3. Look at the web interface.

What is the expected output? What do you see instead?

I get on the web interface:

RAID
Dev.    Capacity    Level    State    Status    Action    Done    ETA
md0    2794.0 GB    raid1    active    OK     resync   
107%    -10.7min

This corresponds (roughly) to /proc/mdstat:

$ cat /proc/mdstat
Personalities : [linear] [raid1]
md0 : active raid1 sda2[1] sdb2[0]
      2929740112 blocks super 1.2 [2/2] [UU]
      [======>..............]  resync = 30.2% (885531648/2929740112) finish=300.7min speed=113284K/sec
      bitmap: 16/22 pages [64KB], 65536KB chunk

unused devices: <none>
$

What Alt-F version are you using? Have you flashed it?

Alt-F 0.1RC3  Flashed.

What is the box hardware revision level? A1, B1 or C1? (look at the label
at the box bottom)
N/A

What is your disk configuration? Standard, RAID (what level)...

Raid1

What operating system are you using on your computer? Using what browser?

Chrome linux.

Please provide any additional information below.

[Anonymous]

Originally posted by: whoami.j...@gmail.com

It is an arithmetic issue (big numbers with 3TB disks, probably awk %d should be replaced with a %f).

The issue must be at /usr/www/cgi-bin/status.cgi, at around line 295 (where $mdev is md0 in your case)

compl=$(drawbargraph $(awk '{printf "%d", $1 * 100 / $3}' /sys/block/$mdev/md/sync_completed))
speed=$(cat /sys/block/$mdev/md/sync_speed)
exp=$(awk '{printf "%.1fmin", ($3 - $1) * 512 / 1000 / '$speed' / 60}' /sys/block/$mdev/md/sync_completed 2> /dev/null)

If it is still resync can you please post the output of

cat /sys/block/md0/md/sync_completed
cat /sys/block/md0/md/sync_speed

Thanks

[Anonymous]

Originally posted by: brian.br...@gmail.com

Still going. Web currently says md0 2794.0 GB raid1 active OK resync 20% 142.2min
which I would think was ok except /proc/mdstat sadly disagrees :-(

$ cat /proc/mdstat
Personalities : [linear] [raid1]
md0 : active raid1 sda2[1] sdb2[0]
      2929740112 blocks super 1.2 [2/2] [UU]
      [===============>.....]  resync = 78.6% (2303036672/2929740112) finish=108.9min speed=95859K/sec
      bitmap: 6/22 pages [24KB], 65536KB chunk

unused devices: <none>
$ cat /sys/block/md0/md/sync_completed
310542592 / 1564512928
$ cat /sys/block/md0/md/sync_speed
89338

awk saying 20% is about right for that sync_completed numbers.

And I just manually tried some big numbers in awk, and it doesn't seem to overflow, so I think awk must be using fp or longs for those calculations already.

So looks like we have a kernel overflow issue here...

Yeah, I just had a look at kernel source md.c, sync_completed_show function.
It uses unsigned long in 2.6.25, and has been fixed to long long sometime since.

Might be wise to change the web script to parse it out of /proc/mdstat instead!

[Anonymous]

Originally posted by: whoami.j...@gmail.com

/proc/mdstat contains very different type/formated information, it is difficult to parse it.

I'm trying to port Alt-F to a more recent kernel, 3.8.11, and perhaps that will solve the issue.

[Anonymous]

Originally posted by: brian.br...@gmail.com

From what I saw in the kernel source, it was definitely fixed by that
version.

[Anonymous]

Originally posted by: crazymac...@gmail.com

I can confirm this on my recently flashed DLINK DNS-323 running Alt-F 0.1RC3. I built a 2x3TB array Raid1 and am seeing he same here - Currently:

RAID
Dev.     Capacity     Level    State     Status    Action     Done    ETA
md0     2794.0 GB     raid1     active     OK     resync     210%    -152.4min

[Anonymous]

Originally posted by: whoami.j...@gmail.com

(No comment was entered for this change.)

Status: Accepted

[Anonymous]

Originally posted by: stephane...@gmail.com

Same here, see my ticket on sourceforge for details:  https://sourceforge.net/p/alt-f/tickets/10/

RAID
Dev.     Capacity     Level    State     Status    Action     Done    ETA
md0     2794.0 GB     raid1     active     OK     resync     158%    -6517.8min

how can I make sure this is a false positive and that the resyncing is actually done?

Stephane

[Anonymous]

Originally posted by: stephane...@gmail.com

I tried the same commands on my box. our problem looks similar

$ cat /sys/block/md0/md/sync_completed
2564345088 / 1564512928

$ cat /sys/block/md0/md/sync_speed
150809

$ cat /proc/mdstat
Personalities : [linear] [raid1]
md0 : active raid1 sda2[1] sdb2[0]
      2929740112 blocks super 1.2 [2/2] [UU]
      [========>............]  resync = 43.8% (1285270528/2929740112) finish=189.7min speed=144439K/sec
      bitmap: 13/22 pages [52KB], 65536KB chunk

unused devices: <none>

[Anonymous]

Originally posted by: brian.br...@gmail.com

Don't worry, cat /proc/mdstat is telling the truth about what's happening, its only the other numbers used by the web interface that are overflowing. (We found there was a fixed kernel bug)

[Anonymous]

Originally posted by: stephane...@gmail.com

Yep I realized that. Thanks Brian!

[João Cardoso]

Is this fixed with RC4? No 3/4TG disks here.