|
With
which adaptec card for scsi ? Is
there any way to do it with ide drives and adaptec 1200 for exemple ? -----Message d'origine----- Ben is right.� You can do the same
thing with a hot-swappable RAID1 array.�
Just unplug the bad one and plug in the new one (the way I understand it
anyway, haven’t had a failure on one yet) and it rebuilds, all online. -----Original Message----- If a RAID 1 set has a failed disk , you
HAVE to break the mirror and recreate the mirror with the new disk. This means Server downtime. If a RAID 5 set has a failed disk, you
simply replace the disk (especially hot pluggable) and the server STAYS
RUNNING.. NO downtime on the server. RAID 5 was designed for this. It does
not give you the same downtime when you have to down the server, replace the
disk and recreate the mirror.. RAID 5 will know you replaced the failed disk
and rebuild it on the fly. The server may see some performance degredation, but
it will stay running..and you dont need to down the server at all. Replaying the log files most certainly does
come into play when you create a new DB.. Ive gone thru this with PSS! -----Original
Message----- How does a RAID 1 (mirroring) not keep you
running in the event of a failure? I'm curious. It most certainly
IS fault-tolerant. If you lose a disk from RAID 1, you are still
running. You don't HAVE to run maintenance until you decide to.
Now, certainly, it would be idiotic NOT to replace the failed disk right away
and break/re-create the mirror, but with newer RAID controllers, you can even
do this online. RAID 5 will give you the EXACT same downtime. You
replace the dead drive, and you wait while your RAID controller rebuilds the
stripe set. But again, what is the difference between the 2 in terms of
time? What, a couple of minutes? I do concede that AS LONG as your
databases and log files are kept on separate spindles, then I personally don't
care whether you use RAID 1 or 5. Replaying the log files comes into play
when you restore the database from tape backup. I don't think it applies
to creating a new database. Circular logging IS on by default, but most
Exchange admins with experience (meaning those that know about Exchange and its
features and why certain features are used and why others aren't) turn that
feature off as one of the first steps once they build a server. Ben Winzenz, MCSE Network/Systems Administrator Peregrine Systems List Charter and FAQ at: http://www.sunbelt-software.com/exchange_list_charter.htm |
Title: Message
- RE : Why would anyone install Exchange on a PDC? G�rard Dumazet
- RE: RE : Why would anyone install Exchange on a PDC? G�rard Dumazet
- RE: RE : Why would anyone install Exchange on a PDC? Allen Crawford
