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FDRDRP Overview | User Experiences | Brochures
As high-capacity cartridge drives such as the IBM 3590 Magstar and StorageTek
9840 continue to replace older 3480/3490E's, Storage Administrators are being
forced to review their disaster recovery procedures.
Today's high-capacity cartridges can hold the incremental backups of hundreds
of disk volumes. Although this greatly reduces the number of cartridges required
to hold each nightÕs backups, it also means that access to those cartridges
becomes a bottleneck during the restore process, as the same cartridges are
needed over and over again. Because of these bottlenecks, some users have found
it too time-consuming to restore from their daily incremental backups. Instead,
they either restore only from the most recent full-volume backup, or they limit
the number of incremental backups that they apply to it. This means that the
restored data is not as current as it could be.
FDRDRP (Disaster/Recovery Product) makes it practical to restore data right
up to the point of the most recent incremental. FDRDRP enhances ABR volume
recovery. With FDRDRP, multiple disk volumes that have been backed up onto
high-capacity tapes can be restored in one pass of each tape. This eliminates
repeated mounts of the backup tapes and greatly reduces the elapsed time of
the disaster restores. As a result, recovery time can be slashed by up
to 80%.
No changes to the ABR backup process are required to achieve these savings!
FDRDRP will slash your Disaster Recovery time:
- You'll be able to spend more time on your DR testing,
and not on your DR restores!
- Get more testing done without expanding your already-stretched
DR window!
Here's what one user of FDRDRP had to say:
"FDRDRP paid for itself! We only have 48 hours
to spend on our DR testing, four times a year. It used
to take us 10 hours to recover our data...now we can do
it in less than three!"
Let's take a look at a simple example to illustrate how FDRDRP operates. The
diagram shows the backups of three DASD volumes--PROD01, PROD02 and PROD03.
Full-volume backups of these disks were taken at the weekend with ABR, and
written to tape 111111. Daily incremental backups were then taken on Monday
and Tuesday evenings, written to tapes 222222 and 333333 respectively.
Ordinarily, the standard ABR Full-volume reconstruct
process would have to mount and rewind each of the tapes 3 times (9 mounts/rewinds)
and would take time to position to the required backup file. FDRDRP,
on the other hand, would mount and rewind each tape only once (3 mounts/rewinds)
and it would eliminate all of the positioning delays. This results in
a typical elapsed time saving of over 80%.
FDRDRP initiates a recovery subtask for each of the three DASD Volumes, which
are then sorted by the tape volser and fileseq required for the first backup.
This allows the subtasks to read the backup files on a tape in physical order
with minimal positioning.
In our example, the restore subtask for PROD01
dynamically allocates and mounts tape 333333 and begins the restore from
File 1 on the tape, which is PROD01's Tuesday incremental. The subtasks
for PROD02 and PROD03 wait for tape 333333.
When the PROD01 restore subtask has finished with tape 333333, the restore
subtask for PROD02 picks up the tape (without rewinding or dismounting
it) and begins the restore from File 2, which is PROD02's Tuesday incremental.
The restore subtask for PROD01 then mounts tape 222222 and starts the restore
from the Monday incremental. And so the process continues until all the weekend
Full backups have been restored and all the tapes dismounted.
The above example was simplified to make the FDRDRP restore process easier
to describe. In the event of a real disaster, hundreds of DASD volumes will
need to be restored. Most Disaster Recovery Centers have a large number of
cartridge drives available and it is essential that these drives are used as
effectively as possible to ensure the most efficient and speedy recovery.
FDRDRP offers the power and control required to get the very best out of the
facilities provided. An FDRDRP job can use multiple cartridge drives and multiple
concurrent FDRDRP restore jobs can be initiated, each restoring a different
set of disk volumes. An operand (MAXTAPES=n), controls the total number of
tape drives that will be devoted to each FDRDRP job. If two jobs require the
same tape volume at the same time, FDRDRP will pass the tape from one job to
the other without dismounting or rewinding it.
So with FDRDRP, you're always in control!
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One ABR user backed up 110 3390-3 volumes onto
high-capacity StorageTek 9840 cartridges, using 8 cartridges for the
weekly full-volume backups and 4 cartridges for one dayÕs incremental
backups. Using FDRDRP, the user then achieved the following results
utilizing 8 cartridge drives for the restore:
- He was able to restore all 110 volumes, using only the
full-volume backups, in 2.5 hours.
- He was able to restore from the full-volume and the incremental
backup in just 3 hours. Applying the incrementals took
just an additional 30 minutes!
Another user backed up
47 3390-9 volumes onto
high-capacity StorageTek 9840 cartridges, using 16 cartridges
for the full-volume backup and 4 cartridges for the incremental
backup.
Again, using FDRDRP, he saw the following results:
- He was able to restore all 47 3390-9 volumes, using the
full-volume backups and the incremental, in just 80 minutes!
Portable Document Format
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