Re: Multi-machine mirroring choices

2008-07-21 Thread Pete French
The *big* issue I have right now is dealing with the slave machine going down. Once the master no longer has a connection to the ggated devices, all processes trying to use the device hang in D status. I have tried pkill'ing ggatec to no avail and ggatec destroy returns a message of gctl

Re: Multi-machine mirroring choices

2008-07-21 Thread Sven W
Pete French presumably uttered the following on 07/21/08 07:08: The *big* issue I have right now is dealing with the slave machine going down. Once the master no longer has a connection to the ggated devices, all processes trying to use the device hang in D status. I have tried pkill'ing

Re: Multi-machine mirroring choices

2008-07-16 Thread Aristedes Maniatis
On 15/07/2008, at 3:54 PM, Jeremy Chadwick wrote: We moved all of our production systems off of using dump/restore solely because of these aspects. We didn't move to ZFS though; we went with rsync, which is great, except for the fact that it modifies file atimes (hope you use Maildir and

Re: Multi-machine mirroring choices

2008-07-16 Thread Andrew Snow
We have deployed an IMAP server running on Cyrus on FreeBSD 6.2, with a 500GB UFS2 partition mirrored with geom_mirror and geom_gate across a dedicated 1gbps link. It has proven to be very stable and reliable after appropriate tweaking. The uptime of the mirror is usually 1-3 months,

Multi-machine mirroring choices

2008-07-15 Thread Sven Willenberger
With the introduction of zfs to FreeBSD 7.0, a door has opened for more mirroring options so I would like to get some opinions on what direction I should take for the following scenario. Basically I have 2 machines that are clones of each other (master and slave) wherein one will be serving up

Re: Multi-machine mirroring choices

2008-07-15 Thread Jeremy Chadwick
On Tue, Jul 15, 2008 at 10:07:14AM -0400, Sven Willenberger wrote: 3) The send/recv feature of zfs was something I had not even considered until very recently. My understanding is that this would work by a) taking a snapshot of master_data1 b) zfs sending that snapshot to slave_data1 c) via

Re: Multi-machine mirroring choices

2008-07-15 Thread Kris Kennaway
Jeremy Chadwick wrote: Compared to UFS2 snapshots (e.g. dump -L or mksnap_ffs), ZFS snapshots are fantastic. The two main positives for me were: 1) ZFS snapshots take significantly less time to create; I'm talking seconds or minutes vs. 30-45 minutes. I also remember receiving mail from

Re: Multi-machine mirroring choices

2008-07-15 Thread Pete French
However, I must ask you this: why are you doing things the way you are? Why are you using the equivalent of RAID 1 but for entire computers? Is there some reason you aren't using a filer (e.g. NetApp) for your data, thus keeping it centralised? I am not the roiginal poster, but I am doing

Re: Multi-machine mirroring choices

2008-07-15 Thread Oliver Fromme
Sven Willenberger wrote: [...] 1) I have been using ggated/ggatec on a set of 6.2-REL boxes and find that ggated tends to fail after some time leaving me rebuilding the mirror periodically (and gmirror resilvering takes quite some time). Has ggated/ggatec performance and stability

Re: Multi-machine mirroring choices

2008-07-15 Thread Sven Willenberger
On Tue, 2008-07-15 at 07:54 -0700, Jeremy Chadwick wrote: On Tue, Jul 15, 2008 at 10:07:14AM -0400, Sven Willenberger wrote: 3) The send/recv feature of zfs was something I had not even considered until very recently. My understanding is that this would work by a) taking a snapshot of

Re: Multi-machine mirroring choices

2008-07-15 Thread Oliver Fromme
Pete French wrote: I am not the roiginal poster, but I am doing something very similar and can answer that question for you. Some people get paranoid about the whole single point of failure thing. I originally suggestted that we buy a filer and have identical servers so if one breaks we

Re: Multi-machine mirroring choices

2008-07-15 Thread Kris Kennaway
Oliver Fromme wrote: Yet another way would be to use DragoFly's Hammer file system which is part of DragonFly BSD 2.0 which will be released in a few days. It supports remote mirroring, i.e. mirror source and mirror target can run on different machines. Of course it is still very new and

Re: Multi-machine mirroring choices

2008-07-15 Thread Pete French
You install a filer cluster with two nodes. Then there is no single point of failure. Yes, that would be my choice too. Unfortunately it didn't get done that way. Mind you, the solution we do have is something I am actually pretty happy with - it's cheap and does the job. We never wanted 100%

Re: Multi-machine mirroring choices

2008-07-15 Thread Wesley Shields
On Tue, Jul 15, 2008 at 07:54:26AM -0700, Jeremy Chadwick wrote: One of the annoyances to ZFS snapshots, however, was that I had to write my own script to do snapshot rotations (think incremental dump(8) but using ZFS snapshots). There is a PR[1] to get something like this in the ports tree.

Re: Multi-machine mirroring choices

2008-07-15 Thread Kris Kennaway
Wesley Shields wrote: On Tue, Jul 15, 2008 at 07:54:26AM -0700, Jeremy Chadwick wrote: One of the annoyances to ZFS snapshots, however, was that I had to write my own script to do snapshot rotations (think incremental dump(8) but using ZFS snapshots). There is a PR[1] to get something like

Re: Multi-machine mirroring choices

2008-07-15 Thread Matthew Dillon
:Oliver Fromme wrote: : : Yet another way would be to use DragoFly's Hammer file : system which is part of DragonFly BSD 2.0 which will be : released in a few days. It supports remote mirroring, : i.e. mirror source and mirror target can run on different : machines. Of course it is still very

Re: Multi-machine mirroring choices

2008-07-15 Thread Jeremy Chadwick
On Tue, Jul 15, 2008 at 07:10:05PM +0200, Kris Kennaway wrote: Wesley Shields wrote: On Tue, Jul 15, 2008 at 07:54:26AM -0700, Jeremy Chadwick wrote: One of the annoyances to ZFS snapshots, however, was that I had to write my own script to do snapshot rotations (think incremental dump(8) but

Re: Multi-machine mirroring choices

2008-07-15 Thread Jeremy Chadwick
On Tue, Jul 15, 2008 at 11:47:57AM -0400, Sven Willenberger wrote: On Tue, 2008-07-15 at 07:54 -0700, Jeremy Chadwick wrote: ZFS's send/recv capability (over a network) is something I didn't have time to experiment with, but it looked *very* promising. The method is documented in the

Re: Multi-machine mirroring choices

2008-07-15 Thread Kris Kennaway
Jeremy Chadwick wrote: On Tue, Jul 15, 2008 at 11:47:57AM -0400, Sven Willenberger wrote: On Tue, 2008-07-15 at 07:54 -0700, Jeremy Chadwick wrote: ZFS's send/recv capability (over a network) is something I didn't have time to experiment with, but it looked *very* promising. The method is