Alexander Zarochentsev wrote: > On Tuesday 30 May 2006 23:20, Arend Freije wrote: > >> Alexander Zarochentsev wrote: >> >>> Hello, >>> >>> On Tuesday 30 May 2006 00:17, Arend Freije wrote: >>> >>>> Hi, >>>> >>>> I'm using Reiser4 for my filesystems on disk (/dev/sda) , and it >>>> works just fine. Recently I bought a second disk (/dev/sdb) for >>>> RAID-1 mirroring. With mdadm I created a degraded raid-1 array on >>>> /dev/md/0, devices missing,/dev/sdb1. After that I created a >>>> Reiser4 filesystem on /dev/md/0 and mounted it at /mnt. Then I >>>> copied the data from /dev/sda1 to /mnt. >>>> >>> would it work better with "no_write_barrier" mount option? >>> >> It would indeed. What's the purpose of this option? >> > > It disables write barrier support in reiser4 which may be buggy. It is > not necessary that reiser4 code has a bug, but the elevator, md device > or disk driver code. > Alexander,
You're probably right. I found several posts on the linux-kernel list involving problems with write barrier support in combination with SATA and ext3 . So I tried: # mkfs -t ext3 /dev/md/0 # mount -o barrier=1 /dev/md/0 /mnt # cp -a $src /mnt # umount /mnt And indeed, umount hangs now as well. So it seems to be a linux-kernel issue after all... If write-barrier support is a known problem, wouldn't it be better to disable it in the Reiser4 driver by default, as in the ext3-driver ? Kind Regards, Arend Freije
