Oh my, I'm being lectured. Perhaps I should elaborate as to not look like a
monkey. =P
I have been watching the list and noticed quite a few people with scheduling
issues on NBU 6.0 and I've seen the back and forth about MP3's short comings
etc. I even think I saw a few people with no issues at all. My reasons for
upgrading to NBU 6.0 are three fold. Believe you me, Management isn't keen on
spending 50,000+ to upgrade the environment unless they have to!
1 - Advanced Client Compatibility with our Hitachi AMS SAN. This eliminates
several of our large backup jobs but allowing NBU's AC to instruct our SAN to
make ":Shadow Images" (Raw Data Copies) on separate LUNS, then I can have a SAN
media server pick them up and dump them to high speed tape.
2 - Given our slow data transfer rates across (mostly) 100MBs connections, we
need Disk Staging (DSSUs) so we can write data to LTO3 or S4 at a reasonable
rate. I'd prefer to have NBU 6's "High Water Mark" as opposed to 5.1's
scheduled dumping. Unfortunately we're not going to be able to muster enough
storage to keep anything on disk longer than it takes to just write it.
3 - Linux Media Servers. We're not currently licensed for them, but I'm 80%
sure we're going to be adding them for their better performance.
With regards to Disk Staging, I doubt I'll get authorization for the 20+ TB I'd
need to keep even one week's backups on Disk for any useful length of time.
Disk staging for me will only be a temporary holding cell for data from
multiple servers until I've got enough to dump the data to tape, then wash,
rinse and repeat.
So my question really isn't how much disk storage do I need to keep a weeks
data around for a week. That's a fairly easy 20 TB or so. But rather, with
High and Low Water Marks (etc) if I'm (for example) dumping to an 800GB LTO3
cart, would a disk staging storage unit of (say) 1.2 TB be sufficient to allow
data to continue writing while the first 800GB is "leaked" off to tape?
-Jonathan
________________________________
From: Tristan Ball [mailto:Tristan.Ball at vsl.com.au]
Sent: Sat 8/19/2006 10:33 PM
To: Martin, Jonathan (Contractor)
Cc: veritas-bu at mailman.eng.auburn.edu
Subject: RE: [Veritas-bu] DSSU Storage?
I'm not sure if you've been watching the list much, but I'd actually
suggest staying with a NBU 5.1 installation, even for a new site, unless
there's something in 6.0 that you absolutely must have. And I wouldn't
normally be so negative about a piece of software, everything has bugs
after all, but these ones are keeping me up nights... :-)
We're still having problems with the scheduler in 6.0mp3, and I know of
several other sites that are too. And the problems are ugly, like jobs
failing to schedule (ie, no obvious errors, just not showing up in the
Activity monitor at all, which is harder to catch!), or my current
favourite, running different schedules for individual child jobs of a
single parent job, even when some of those schedules are nowhere near
being "in window" - days out in fact.
In regards to DSSU's, it really depends a lot on how long you'd like to
keep the data on disk for. I actually work at about 4 x Backup set size,
on the grounds that we want 2 x Full backups ("this" one + "last" one),
plus the incremental/differentials in between. To be honest, that's got
a little bit expensive for us, so I'm actually running at about 1.5x
backup set size, destaging to tape almost immediately, and expiring the
images from disk straight away. Instead of NBU, we're relying on
filesystem snapshots for "day to day" end user recovery, and using the
tapes purely for DR & emergencies.
I would also recommend that you have a look at Netbackup Vault, if you
can. Running DSU's + Vault has actually proven very effective for us,
and it's more flexible in it's destaging options that a plain DSSU.
Regards,
T.
---
Tristan Ball
System Administrator
Vision Systems
+61-3-9211-7064
-----Original Message-----
From: veritas-bu-bounces at mailman.eng.auburn.edu
[mailto:veritas-bu-bounces at mailman.eng.auburn.edu] On Behalf Of Martin,
Jonathan (Contractor)
Sent: Friday, 18 August 2006 8:39 PM
Cc: veritas-bu at mailman.eng.auburn.edu
Subject: [Veritas-bu] DSSU Storage?
I'm working on architecting a new backup solution here, which will
undoubtedly require Disk Staging to accommodate faster drives (LTO3 or
DLT-S4.) I'm sure this is a common way to get around the limited
bandwidth associated with copper network connections. Anyhow, how big
is everyone's DSSUs? 2x Media? More? How about your High Water Marks?
I'm thinking something along the lines of 50% high water mark with
DSSU's 2x Media (compressed.) Also, lets say your DSSU gets up to 40%
when the backup window finishes, is there a setting to flush this after
a certain amount of time? I'm installing 6.0 for the first time here
shortly, so all the new features are presently a mystery to me.
TIA,
-Jonathan
_______________________________________________
Veritas-bu maillist - Veritas-bu at mailman.eng.auburn.edu
http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
|
