[dm-devel] dmsetup status not clear

[Asif Iqbal]

On Thu, Mar 5, 2009 at 11:20 AM, Konrad Rzeszutek
<konrad at virtualiron.com> wrote:
>> Why is the new disk showing up as `sdc' instead of `sdb'  and why is
>
> I can't comment on the naming - but in regards to the write cache - that is
> the information the kernel gets from the device using SCSI commands (to be
> exact it MODE_SENSE). The device has it disabled. You can fiddle with MODE_SELECT
> command if you want to enable it - but keep in mind that when you have a RAID
> it is advised to turn cache off. Unless your computer has a UPS connected so that
> you can flush the data immediately and turn off caching.
>
>> the write cache disabled?
>>
>>
>> Of course similar two lines below showing up only in dmesg and not in
>> messages file
>>
>>
>> [ 2465.456628] ata4: exception Emask 0x10 SAct 0x0 SErr 0x150000
>> action 0xe frozen
>> [ 2465.543901] ata4: SError: { PHYRdyChg CommWake Dispar }
>> [ 2465.606247] ata4: hard resetting link
>>
> That is OK.
>>
>> Also, how can I find out if/when the raid1 sync completed? I do not
>> follow what the dmsetup status is saying
>
> cat /proc/dmstatus should give you some details.

~# cat /proc/dmstatus
cat: /proc/dmstatus: No such file or directory

>
>>
>>
>> ~$ sudo dmsetup status
>> nvidia_eeffhbef5: 0 6458067 linear
>> nvidia_eeffhbef1: 0 149838192 linear
>> nvidia_eeffhbef: 0 156301486 mirror 2 8:0 8:16 1183/1193 1 AD 1 core
>
> That is just the static mapping it has setup. Where it says that disks 8:0 and 8:16
> are part of the of your RAID. Do a 'ls /dev/ | grep 8' and you will see what
> the 8:0, and 8:16 correspond to.


iqbala at ftp0:~$ ls -al /dev/ | awk '$5 ~ /8/ {print}'
drwxr-xr-x  2 root   root       12680 2009-03-05 11:30 char
drwxr-xr-x  3 root   root         180 2009-03-05 11:29 input
crw-------  1 root   root    108,   0 2009-03-04 11:58 ppp
brw-rw----  1 root   disk      8,   0 2009-03-05 11:29 sda
brw-rw----  1 root   disk      8,   1 2009-03-05 11:29 sda1
brw-rw----  1 root   disk      8,   2 2009-03-05 11:29 sda2
brw-rw----  1 root   disk      8,   5 2009-03-05 11:29 sda5
brw-rw----  1 root   disk      8,  16 2009-03-05 11:29 sdb
brw-rw----  1 root   disk      8,  17 2009-03-05 11:29 sdb1
brw-rw----  1 root   disk      8,  18 2009-03-05 11:29 sdb2
brw-rw----  1 root   disk      8,  21 2009-03-05 11:29 sdb5

I see 8:0 is sda and 8:16 is sbd, cool!

The dmsetup status has a little different output now

iqbala at ftp0:~$ sudo dmsetup status
nvidia_eeffhbef5: 0 6458067 linear
nvidia_eeffhbef1: 0 149838192 linear
nvidia_eeffhbef: 0 156301486 mirror 2 8:0 8:16 1193/1193 1 AA 1 core

It was '1183/1193 1 AD 1 core' and now '1193/1193 1 AA 1 core'

What are the differences? Is there some doc where I can read more about this?

>
>>
>>
>> --
>> Asif Iqbal
>> PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu
>> A: Because it messes up the order in which people normally read text.
>> Q: Why is top-posting such a bad thing?
>>
>> --
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>> https://www.redhat.com/mailman/listinfo/dm-devel
>
> --
> dm-devel mailing list
> dm-devel at redhat.com
> https://www.redhat.com/mailman/listinfo/dm-devel
>



-- 
Asif Iqbal
PGP Key: 0xE62693C5 KeyServer: pgp.mit.edu
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?