Backup Central

Hi,
If some tape drives are used in two storage pools, how to solve the race
condition problem? suppose two clients are going to backup (or restore) to
these two storage pools simultaneously. Is there any way to set this
priority?

Regards,
Mehdi

On Mar 10, 2010, at 5:39 AM, Mehdi Salehi wrote:

Hi,
If some tape drives are used in two storage pools, how to solve the race
condition problem? suppose two clients are going to backup (or restore) to
these two storage pools simultaneously. Is there any way to set this
priority?

What race condition problem? The two clients simply use the existing drives, and tapes are provisioned according to TSM rules, as described in the Admin Guide manual, where collocation settings contribute to the apportionment. Most sites implement a disk storage pool ahead of tapes to buffer "ordinary" backups (whoppers can go directly to tape).

Richard Sims

Say there is not disk storage pool and two clients from the two tape storage
pools accidentally sent their backups exactly at the same time. Which one
graps the tape drive first?

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November 23rd and returning to the office Monday December 7th.

If this matter is urgent, please call our office at 905-660-7080 and ask for
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Otherwise, I will return your email as soon as I can.



Have a great day,



Elana Samuels

Tier 1 Data Solutions Inc.

Tel 905-597-8995

Cell 416-277-9544

<mailto:elana < at > tier1datasolutions.com> elana < at > tier1datasolutions.com

'Just Set It And Forget It'






Elana Samuels

Tier 1 Data Solutions Inc.

Tel 905-597-8995

Cell 416-277-9544

<mailto:elana < at > tier1datasolutions.com> elana < at > tier1datasolutions.com

'Just Set It And Forget It'

On Thursday 11 March 2010, you wrote:
Say there is not disk storage pool and two clients from the two tape
storage pools accidentally sent their backups exactly at the same time.
Which one graps the tape drive first?
The first one. There is aways 1 that will the first.
A restore will cancel a lower process like reclamation or migratition to free
up a tape drive.

You _can_ have a dead lock on tape drives where 1 process is waiting for a
tape in use by an other process and vice versa. I have seen this on older TSM
server software ( <5.x.x).


Stef

On Thu, 11 Mar 2010 08:32:20 +0330, Mehdi Salehi <ezzobad < at > GOOGLEMAIL.COM> said:

Say there is not disk storage pool and two clients from the two tape
storage pools accidentally sent their backups exactly at the same
time. Which one graps the tape drive first?

"exactly" the same time, isn't. One of them is first, even if it's a
matter of which thread gets executed first.

In any case, there's only one lock for a tape drive. When that DRIVE
is moved from IDLE to WAITING FOR MEDIA, the other process is out of
luck, it will wait.

- Allen S. Rout