arrangement that has no intrinsic internal knowledge of whether devices
it is given are truly multipath devices. As such, this is a simplistic
approach, but still a useful one.
The basic approach is to (at present- this will change soon) use camcontrol
to find likely identical devices and and label the trailing sector of the
first one. This label contains both a full UUID and a name. The name is
what is presented in /dev/multipath, but the UUID is used as a true
distinguishor at g_taste time, thus making sure we don't have chaos
on a shared SAN where everyone names their data multipath as "Fred".
The first of N identical devices (and N *may* be 1!) becomes the active
path until a BIO request is failed with EIO or ENXIO. When this occurs,
the active disk is ripped away and the next in a list is picked to
(retry and) continue with.
During g_taste events new disks that meet the match criteria for existing
multipath geoms get added to the tail end of the list.
Thus, this active/passive setup actually does work for devices which
go away and come back, as do (now) mpt(4) and isp(4) SAN based disks.
There is still a lot to do to improve this- like about 5 of the 12
recommendations I've received about it, but it's been functional enough
for a while that it deserves a broader test base.
Reviewed by: pjd
Sponsored by: IronPort Systems
MFC: 2 months
- First configured key is based only on keyfile (no passphrase).
- Device is attached.
- User changes first key (setkey) from keyfile to passphrase and doesn't
specify number of iterations (with -i option).
...geli(8) won't store calculated number of iterations in metadata.
This result in device beeing unaccesable after detach.
One can recover from this situation by guessing number of iterations
generated, storing it in metadata and trying to attach device.
Recovery procedure isn't nice, but one's data is not lost.
Reported by: Thomas Nickl <T.Nickl@gmx.net>
MFC after: 1 week
gmirror and graid3 in a way that it is not resynchronized after a
power failure or system crash.
It is safe when gjournal is running on top of gmirror/graid3.
read requests to its consumer. It has been developed to address
the problem of a horrible read performance of a 64k blocksize FS
residing on a RAID3 array with 8 data components, where a single
disk component would only get 8k read requests, thus effectively
killing disk performance under high load. Documentation will be
provided later. I'd like to thank Vsevolod Lobko for his bright
ideas, and Pawel Jakub Dawidek for helping me fix the nasty bug.
- after killing all attached providers, all providers are then detached
and operation is repeated for those who were attached,
- we don't want to remove keys for read-only attached providers, we only
want to detach them.
MFC after: 1 week
Now, encryption algorithm is given using '-e' option, not '-a'.
The '-a' option is now used to specify authentication algorithm.
Supported by: Wheel Sp. z o.o. (http://www.wheel.pl)
supported for a moment.
- Don't allow to use -i when no passphrase is given. Now if iterations is
equal to -1 (not set), we know that we should not ask for the passphrase
on boot.
It still doesn't handle situation when one key is protected with
passphrase and the other is not. There is no quick fix for this.
The complete solution will be to make number of iterations a per-key
value. Because this need metadata format change and is only needed for
devices attached on boot, I'll leave it as it is for now.
MFC after: 3 days
- number of read I/O requests,
- number of write I/O requests,
- number of read bytes,
- number of written bytes.
Add 'reset' subcommand for resetting statistics.
