[SGVLUG] Suggestions for business application server

[matti]

Hi,

> Has anyone
> replaced SCSI with SATA in
> high-reliability environment.  (Non-SQL files with
> lots of record-based
> I/O.) 

better quality SATA drives can do well enough for
many applications now. ( note, the consumer rated
SATA desktop drives are not as reliable as the 
"enterprise" or server rated drives - or so I was
told at a storage conference I went to. )

SCSI/SAS are pricey still imho and I would really
want to see them only on systems which really
needed the performance. I really wished their
price points would be closer to SATA.

> I have read
> that RAID5 is less preferable
> to RAID10 or other configurations due to its
> slowness. 

RAID 10 is in general supposed to be the fastest
solution, however RAID 5 or RAID 6 can be good
enough for many applications.

> Also read
> that it is better to not keep
> the OS on the main RAID array. 

in general I prefer to have the system OS on 
a RAID 1 pair, and data on a separate 
RAID 5/6/10 set.

> Are there
> significant advantages to go to
> RHEL 5, and can the backup system stay RHEL
> 4? 

are we talking about backup of the data/
or a backup server to run the applications
if the first server dies.

if just a backup of the data, then it is fine,
although I prefer to keep all the OSes to the
same level whenever possible to reduce complexity
of admin. ( and the more current stable version,
typically the less security hole/bug issues.. )

if it is a failover server to run the applications,
it should be the same version...

this is where the virtual machines work well...
running applications.

> We are
> currently making nightly full
> backups onto DLT VS1 tapes.  (2 week rotation and
> archiving the Month-End
> tape.)  
> 
> Because
> tape drive & tapes are
> relatively expensive, I am investigating a cron-driven
> backup to USB
> hard-drives as a replacement. 

if you are going to use external USB drives, better
keep at least 2 copies... hard drives just die too
frequently, even if not spinning.

I trust dropping a tape on the floor more than
a hard drive... tapes in general work better
( tho I have seen some of the critical plastic
parts on a tape drive break on a fall... argh a
real PITA! )

best
matti