---Guy (via iPhone)
On 9 Mar 2011, at 01:22, Phil Stracchino <ala...@metrocast.net> wrote: > I just had a very odd (and rather alarming, for a few minutes) event happen. > > Five days ago, I received a new box of blank LTO2 tapes. > On Sunday, I deleted the first six old LTO1 tapes from my FULL-TAPE pool > and labelled six of the new LTO2 tapes, ARCH-0001 through ARCH-0006, in > preparation for the full backups scheduled to begin at 0430 yesterday. > The backups ran rather slowly, writing three tapes, ARCH-0001 through > ARCH-0003, before eventually stalling at the writing-attributes stage. > (I think I know why that happened. I'll come back to that later.) > > Late this morning, I eventually killed the stalled backups, deleted the > jobs, purged the three tapes used, and marked them RECYCLE. Then I > restarted MySQL and Bacula (more on that later), then restarted all the > backups, by hand. The smaller backups ran to completion fine; the main > server backup filled the first LTO2 tape not long ago and requested a > second tape. It requested ARCH-0004, as ARCH-0004 is the first > completely unused appendable volume. I have it set to ACCEPT ANY > VOLUME, so I loaded the correct tape, ARCH-0002, and clicked Mount in BAT. > > This is where I had an adrenaline-rush moment, because after mounting > the tape BAT storage daemon status reported the storage daemon as > mounted WITH ARCH-0004. I double-checked to ensure that I had > physically inserted ARCH-0002 into the drive, and sure enough, it was. > The display did not update to correctly show the mounted volume as > ARCH-0002 until Bacula wrote the first 5GB "file" to the tape. That > gave me a few bad minutes. I did NOT want to have to kill the full > backup and start it over. > > (The first tape always seems to be slow to fill, because many small > files are written to it. It took seven hours to write 226GB of data to > the first tape, an average of about half a gigabyte per minute. By the > time Bacula gets into the second tape, it's into the big storage array > which mostly contains multi-megabyte to multi-gigabyte files, and it's > now writing about 1.3GB/minute.) > > Are you spooling? If not you should try it. It will speed up your backs no end and prolong the life of your tapes. Prevents the shoeshine effect. > Now, I said I'd get back to the MySQL issues. I was reading through > some documents about mySQL on ZFS, and came across (again) a > recommendation from one MySQL tester that reported the best MySQL > performance from setting the InnoDB buffer pool small, 100MB or so, and > allowing ZFS to do the data caching. And I thought, "You know, I don't > believe I've ever tried this. I'll give it a shot and see how it goes." > > Well, after trying this, I can now definitively state: DO NOT DO THIS > IF YOUR BACULA CATALOG IS ON MYSQL. It may well work well for general > usage, but for Bacula, this configuration trick DOES NOT WORK. If you > are using Bacula with a MySQL catalog database on ZFS, configure MySQL > as you would if it were NOT on ZFS. Do NOT rely on the "let ZFS cache > the data" trick, because it won't work with Bacula. > > > > -- > Phil Stracchino, CDK#2 DoD#299792458 ICBM: 43.5607, -71.355 > ala...@caerllewys.net ala...@metrocast.net p...@co.ordinate.org > Renaissance Man, Unix ronin, Perl hacker, SQL wrangler, Free Stater > It's not the years, it's the mileage. > > ------------------------------------------------------------------------------ > Colocation vs. Managed Hosting > A question and answer guide to determining the best fit > for your organization - today and in the future. > http://p.sf.net/sfu/internap-sfd2d > _______________________________________________ > Bacula-users mailing list > Bacula-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/bacula-users ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d _______________________________________________ Bacula-users mailing list Bacula-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/bacula-users
