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Re: D2D backup solutions for VMS

 
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robert70
Valued Contributor

D2D backup solutions for VMS

Hello,
We ahve a DS20E Alpha Server running VMS 7.3-2
and hosting an Oracle Database 9i on a StorageWorks MSA1000 RAID Array.

We are finding backup and Restore operations onto SDLT Tape taking too long. Our Restore Operation of the Database takes about 3-4 hours - 175Gb of data compressed

Can you advise on possible Disk to DIsk solutions to enhance our backup eg keep the magnetic tape backup say once a week but do a D2D daily backup -

Thanks
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Robert Gezelter
Honored Contributor
Solution

Re: D2D backup solutions for VMS

Robert,

Does "backup" mean an image of the entire volume, or does it mean a backup of the data in the database.

If one means backup of the drive, then the least downtime is generally adding an additional member to the shadow set, waiting for it to become synchronized, quiesce the volume (ensure that the database is consistent), disconnecting the spare shadowset member, and then continuing operation.

This does require that the database and the applications cooperate.

The backup volume can be retained online, or backed up to tape while the system continues operation. If the original volumes need restoration, the backup disk can be used as the source for a replacement shadow set (and a base for applying audit journals).

- Bob Gezelter, http://www.rlgsc.com
robert70
Valued Contributor

Re: D2D backup solutions for VMS

It would be to backup the data and not the volume - we currently have the RAID configured with NO shadow sets but but using RAID 5 - striping etc for the database backup.

how would it work in this case?



marsh_1
Honored Contributor

Re: D2D backup solutions for VMS

HI,

is the tape drive a standalone or part of a library, is it direct attached or san attached, the msa1000 again is that direct attached or san attached. do you have access to a san with other storage resources. are there any current backup software solutions employed at your site that you could utilise .

hth

robert70
Valued Contributor

Re: D2D backup solutions for VMS

Tape Drive stand-alone connected via SCSI
No other SAN available in office.No other resources available.
robert70
Valued Contributor

Re: D2D backup solutions for VMS

The MSA1000 is directly connect to the Alpha via fibre optic cable.
marsh_1
Honored Contributor

Re: D2D backup solutions for VMS

hi,

so it sounds like you have a substantial backup window (potentially 3-4 hours) where the database is down.
do you have room in the msa1000 for more disks, or budget for another shelf/disks ?
if so create a new raid5 or 1+0 lun for disk to disk backup (suggest raid 1+0 for better write performance if you can afford it) once complete you can get a tape backup done from the backup volume while the application and database is brought back up. roughly speaking you will get about up to 150 mb/s max reading from the raid 5 , writing to the raid 1+0 at 100 mb/s max.
back the other way you are looking at 150 mb/s read from the raid 1+0 , 68 mb/s write to the raid 5 for restore.
i'll leave you to do the maths but it should substantially reduce your backup window, a daily tape backup will provide extra redundancy with only impact being the system resources required for a tape backup.
the other way as bob has suggested still involves creating extra luns and implementing shadowing.

hth

note:- above figs based on 64k sequential reads/writes with 14 drives (36gb 15k rpm), different configurations (ie slower or larger drives) will affect performance.

robert70
Valued Contributor

Re: D2D backup solutions for VMS

thanks
yes we have room for another 10 disk arrays in our config so we could place in a few 36.4 gb drives.
Would the backup on D2D be standard or do you normally compress?
robert70
Valued Contributor

Re: D2D backup solutions for VMS

it take 1+0 setup is a shadow set config?
we have raid5 eg one stripping disk in 2 disk volumes - dkb200 and dkb300 both have 145gb physical space - 5 x 36.4 Gb in each
Robert Gezelter
Honored Contributor

Re: D2D backup solutions for VMS

Robert,

RAID 0+1 has far higher performance than RAID 5, particularly for writes (as disk prices have come dramatically down, the balance has tilted towards RAID 0+1 in terms of price performance).

Using Host Based Volume Shadowing to bring an extra set of drives into the shadow set allows the downtime window to be reduced to mere moments, as I noted in my post. The duplication of the data occurs in parallel with normal operation. The extra volumes can then be remounted privately for tape backup.

Generally, what is needed is the licensing for host based volume shadowing, and the extra drives.

Note that this is different from controller based RAID.

- Bob Gezelter, http://www.rlgsc.com