On Oct 31, 4:43am, Mickey Beddingfield wrote:
> Sorry, but there seems to be a disconnect here? I have been talking about
> moving volumes to a nearline storage device that looks like a disk or
> disks. Some of these devices use optical media and some use tape & staging
> disks. If you use a device like this then this partition or partitions can
> be mounted under AFS & thus you have a bigger cell so all the info is still
> in the VLDB, etc. We are looking at a device like this now and expect our
> cost/MB to be ~$.20/MB vs real disk at ~$.45/MB vs RAID at ~$.75/MB
I think the confusion was due to my misunderstanding of your way of using the
nearline storage. Using them as disks certainly sounds interesting. Can you
recommend some of such devices with tapes that you mentioned? If this approach
with reliable/fast tapes can materialize, the cost/MB should be much less then
$.20/MB? I guess you are concerned with the access rate with tapes. But would
it be a good trade-off for the volumes that are not accessed at all?
> > If a volume stay migrated for a long time, the backup done before the
> migration
> > might get expired and overwritten. This is especially true if you are
> using
> > the AFS backup system (backup, butc, buserver) and tape recycling, right?
>
> We build backup lists every night to determine what volumes need to be
> backed up full or incremental. We can specify what servers/partitions will
> be backed up, thus we can elect not to backup this nearline storage devices
> partition or partitions. Also, we keep our weekly full backups for three
> years so unless our users need something for more than 3 years we are
> covered.
The need for a backup of the migrated volumes is unlikely with such a long
retention period of your weekly full backup. I agree.
Shyh-Wei
