Snapshots fail on large FFS2 volumes regulary -- how to backup /usr/home?!

[Lev Serebryakov]

Hello, Freebsd-fs.

  I have /usr/home partition on my new server which is 400GiB (only
17GiB is used). It is UFS2, SoftUpdates are enabled.

  I want to backup it on live system, but 4 times out of 5 I got
(after 10-12 minutes of wait! Oh my, 10 minutes to create snapshot!):

mksnap_ffs: Cannot create snapshot /usr/home/.snap/dump_snapshot: Resource temporarily unavailable
dump: Cannot create /usr/home/.snap/dump_snapshot: No such file or directory

  It is FreeBSD 8.2-STABLE/amd64, 8GiB of memory.

  I've never encounter such problem on previous server, which has
 about 80GiB (with 20GiB used).

-- 
// Black Lion AKA Lev Serebryakov <lev at FreeBSD.org>