Our MySQL backup solution is done using ZFS snapshots, and then
copying the snaps off to a NFS target. But I don't think there's any
reason why ibbackup targetted at the NFS target wouldn't be an
equivalently good solution.

-J

On Thu, Jun 5, 2008 at 4:15 PM, Ben Rockwood <[EMAIL PROTECTED]> wrote:
> Ethan Erchinger wrote:
>> Hello,
>> We have a backup strategy that involves mapping LUNs between a given
>> pair of hosts, and copying data from one of the LUNs (src) and another
>> LUN (dest).  The src LUNs sit a SAN device, sometimes multiple devices
>> (zpool mirror).  The src LUN is running a MySQL database and typically
>> will be running for weeks without issue.
>>
>> When we start the backup sequence, we map a previously unmapped LUN to
>> the DB host and issue the following commands:
>>
>> root# cfgadm -al
>> (sleep 10)
>> root# luxadm probe
>> (sleep 10)
>> root# zpool import <pool_name>
>>
>> After importing we'll perform some minor IO on the dest LUN, such as
>> adding a symlink, removing some old configuration files.  Then we'll
>> start an ibbackup of that database from the src LUN to the dest LUN,
>> and things go bad.
>>
>> It's not completely consistent, but sometimes the DB host will crash,
>> sometimes we'll get chksum/read/write errors on the src LUN.  Looking
>> at dmesg (when the host doesn't crash), we see the LUNs paths all
>> disappear and then reappear usually around 20 seconds later.  Example
>> output below.  Each LUN has 2 paths out of the DB host and 4 paths on
>> each storage device, across two separate SANs.
>>
>> Usually the host will crash when not running with a zpool mirror,
>> which apparently in Sol10u4, it's expected behavior.
>>
>> These hosts are x86_64 servers, running Sol10u4, unpatched.  They use
>> qlogic qla2342 HBAs, and the stock qlc driver.  They are using MPXIO,
>> from what I can tell.
>>
>> If anyone has any tips on troubleshooting, or knows of things we are
>> doing wrong, help would be appreciated.
>
>
> Hey Ethan,
>
>  Gotta tell you, this is a pretty gutsy and interesting backup solution. :)
>
>  While I'll give you props for coming up with something innovative I'd
> strongly recommend against this type of solution.  Manipulation like
> this really is flirting with a panic.  Adding and removing devices too
> frequently on FC is in my experience dangerous in production environments.
>
>  If you want to stick with a solution on FC I'd recommend looking at AVS
> Instant Image and/or Remote Mirror
> (http://www.opensolaris.org/os/project/avs/).  That'll give you a proper
> replication solution.
>
>  Since your running ZFS, I _highly_ recommend snapshotting the
> filesystem containing MySQL data and then using zfs send/recv to move
> the data to a remote host.
>
>  Since you paid good money for ibbackup, I'm going to assume you like
> it and have a production database that you want to be gentle too.  I'd
> consider using NFS as a backup destination or providing a backup
> destintation LUN to the server and just leaving it, perhaps using UFS so
> that you could mount it elsewhere easily without importing/exporting
> LUNs on the host.
>
>  My philosophy with FC on Solaris in a production environment is to set
> it and step away.  If you can utilize ethernet, particularly with ZFS
> send/recv I think you'll be happier and avoid the cost of ibbackup.
>
>
>  I didn't really answer your question, but hopefully there are some
> options here that might be more appealing.  If you want additional
> detail on any of them please let me know.
>
>  benr.
> _______________________________________________
> storage-discuss mailing list
> [email protected]
> http://mail.opensolaris.org/mailman/listinfo/storage-discuss
>
_______________________________________________
storage-discuss mailing list
[email protected]
http://mail.opensolaris.org/mailman/listinfo/storage-discuss

Reply via email to