Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Is there a magic command which would check consistency of data between
the hosts?
Let's say you have two DRBD hosts called "primary" and "secondary":
on primary {
device /dev/drbd1;
disk /dev/san1_data/host;
(...)
}
on secondary {
device /dev/drbd1;
disk /dev/san2_data/host;
(...)
}
You accidentally write directly to "/dev/san2_data/host" - this means
the data on the secondary host is no longer consistent. Or your
senondary system silently corrupts data.
If you don't notice it, you're in trouble.
How can I check the consistency of data with DRBD?
I imagine it would work like that:
- tell DRBD on both sides to read 1 MB of data in an atomic way
- send checksums and compare if they are the same
- if the checksums are not the same, resend data from the master to the
primary - self repairing
- read the next 1 MB of data...
Is it possible to check resource consistency with DRBD?
--
Tomasz Chmielewski
http://wpkg.org