On Wed, May 31, 2017 10:39 am, Paul Heinlein wrote:
On Wed, 31 May 2017, m.roth@5-cent.us wrote:
I've got an old RAID that I attached to a box. LSI card, and the RAID has 12 drives, for a total RAID size of 9.1TB, I think. I started shred /dev/sda the Friday before last... and it's still running. Is this reasonable for it to be taking this long...?
Unless you specified non-default options, shred overwrites each file three times
With modern drives (read: larger than 100GB) writing the track over once with anything will be sufficient. Overwriting multiple times with different information was used awfully long ago when track had noticeable width and distinct edge (drives were smaller than 1 GB then), thus it was possible to distinguish narrow side of older record (using much more sensitive equipment)) as newly recorded track is usually slightly shifted with respect to old one, so narrow stripe of old one is not covered on one side. These times are long gone, one can clean drives one at a time just overwriting the whole device using dd (mind bs size to not impend speed). Better though: physically destroy platters, it may take less of _your_ time to do that.
Just my $0.02
Valeri
-- and writing 27 TB to an old RAID array will be extremely slow. Also, shred has a builtin PRNG, and I'm not really sure how speedy it is.
Still, 12 days seems like a really long time...
-- Paul Heinlein <> heinlein@madboa.com <> http://www.madboa.com/ _______________________________________________ CentOS mailing list CentOS@centos.org https://lists.centos.org/mailman/listinfo/centos
++++++++++++++++++++++++++++++++++++++++ Valeri Galtsev Sr System Administrator Department of Astronomy and Astrophysics Kavli Institute for Cosmological Physics University of Chicago Phone: 773-702-4247 ++++++++++++++++++++++++++++++++++++++++