[dm-crypt] slow read performance, but fast writes?
mbroz at redhat.com
Thu Sep 15 12:45:40 CEST 2011
On 09/15/2011 11:49 AM, Nikolay Kichukov wrote:
> this query is best suited for md-raid mailing list as what you measure:
> dd if=/dev/md3 of=/dev/null bs=1M
> does not involve any decryption. You are reading directly from the md device and there is no matter what is actually there.
heh. I read that as crypt device and it is MD directly, sorry for confusion.
Seems my brain is still in different timezone :)
yes, this test has nothing to do with crypt.
Anyway, it is interesting that the problem is there even without crypt,
perhaps you should ask on linux-raid list then.
for badblock - I guess it just submits all IO from one cpu,
so only one core is used for encryption in fact. There applies the same what I wrote before.
More information about the dm-crypt