[PATCH] RFC: Don't relly on /proc/mdstat when enumeraing RAID levels.

Jan Safranek jsafrane at redhat.com
Mon Apr 22 08:03:47 UTC 2013


On 04/19/2013 05:27 PM, David Lehman wrote:
> On Fri, 2013-04-12 at 16:55 +0200, Jan Safranek wrote:
>> /proc/mdstat can be empty or contain mostly random RAID levels. Blivet
>> should either modrpobe all RAID kernel modules (raid0, raid1, raid456, raid10)
>> which then populate /proc/mdstat correctly, or don't read /proc/mdstat at all.
>>
>> This patch simply removes parsing of /proc/mdstat. Do we expect that someone
>> runs Blivet on a kernel which does not support certain RAID levels?
> 
> I'm comfortable with telling users not to try to make arrays using
> levels their system does not support.
> 
> I like this patch. Can you verify that mdadm will load the appropriate
> module if/when mdadm is asked to create an a new array?

Sure, it works as expected

$ cat /proc/mdstat
Personalities :
unused devices: <none>

$ lsmod | grep raid

$ mdadm -C /dev/md/mymd -l 0 -n 2 /dev/sdb1 /dev/sdb2
...

$ cat /proc/mdstat
Personalities : [raid0]
md127 : active raid0 sdb2[1] sdb1[0]
      192512 blocks super 1.2 512k chunks

$ lsmod | grep raid
raid0                  17842


$ mdadm -C /dev/md/mymd2 -l 5 -n 3 /dev/sdb5 /dev/sdb6 /dev/sdb7
...
$ cat /proc/mdstat
Personalities : [raid0] [raid6] [raid5] [raid4]
md126 : active raid5 sdb7[3] sdb6[1] sdb5[0]
      191488 blocks super 1.2 level 5, 512k chunk, algorithm 2 [3/3] [UUU]

md127 : active raid0 sdb2[1] sdb1[0]
      192512 blocks super 1.2 512k chunks

$ lsmod | grep raid
raid456                82225  1
raid0                  17842  1
async_raid6_recov      17160  1 raid456
async_memcpy           12722  2 raid456,async_raid6_recov
async_pq               13179  2 raid456,async_raid6_recov
raid6_pq              101472  2 async_pq,async_raid6_recov
async_xor              12949  3 async_pq,raid456,async_raid6_recov
async_tx               13293  5
async_pq,raid456,async_xor,async_memcpy,async_raid6_recov



More information about the anaconda-patches mailing list