Best Practice to create the No of tape slot

The technical support forum for Firestreamer (the virtual tape library).
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shermaine
Posts: 3
Joined: 06 Apr 2016, 16:13

Best Practice to create the No of tape slot

Post by shermaine » 16 May 2016, 14:02

Hi expert,
We use external USB Drive with firestreamer library for Ms DPM 2012 R2 tape backup, the USB drive is 5TB and we create 5 drive and 10 slot to load into Firestreamer. However I also got warning telling "The Number of free tapes in the tape Library Firestreamer Media Changer is less or equals the threshold value of 2. You must add to the library and mark it as free in order to prevent future backup from failing. (ID 3305)

If say I need reserve 2 free slot, then the usage space reduced, I am planning to modify the firestream library, change to 15 slot. (In stead of 10) however I am new to the system, and not sure if that is the best practice and what will be the possible impact to increase the slot, without increase the actual USB drive capacity.

Many thanks in advanced and appreciate your earlier reply

SM

jsf
Cristalink Support
Posts: 300
Joined: 29 Aug 2010, 09:03

Re: Best Practice to create the No of tape slot

Post by jsf » 17 May 2016, 11:56

Why did you need to reduce the number of slots from 200 to 10? We do not recommend changing the default configuration of 5 tape drives / 200 slots, unless you really need to. For Firestreamer, it's not a problem. But from DPM's and your standpoint, every time you change Firestreamer's configuration, the old library disappears and the new one appears. Does it really worth the trouble?

In terms of the number of tape drives / slots, from Firestreamer's standpoint, there is no "best practice", except as per above.

The DPM warning you referred to tells you that you need to have a certain number of free tapes loaded, so that DPM could use them when needed. It seems that DPM wants 20% of slots to be loaded with free tapes. But in the end it doesn't really matter. You can ignore the warning if you feel, for example, that one free tape is enough. However, DPM may use your free tape and then ask for another. Your backups will then wait until you load a new tape.
Best regards,
John Smith
Cristalink Support

shermaine
Posts: 3
Joined: 06 Apr 2016, 16:13

Re: Best Practice to create the No of tape slot

Post by shermaine » 17 May 2016, 13:17

Thank you John.
The system was deployed by someone else with 1 drive and 10 slot initially, to speed up the backup performance, I changed it to 5 drive. I guess the reason why change to 10 as 200 sounds too much, all appear on the hard drive and make confusion.We totally has 6TB data to be backup, not that much, can I use 20 slot in stead of 200?

What is the concerns of making it 20, not 200?

Many thanks again

SM

jsf
Cristalink Support
Posts: 300
Joined: 29 Aug 2010, 09:03

Re: Best Practice to create the No of tape slot

Post by jsf » 20 May 2016, 07:57

1 drive and 10 slot initially, to speed up the backup performance
I am not sure how changing the number of tapes drives/slots from default 5/200 to 1/10 can possibly increase performance.
200 sounds too much, all appear on the hard drive and make confusion
There are "slots" and there are actual tapes. There is no requirement to fill all the slots with tapes. You can have 200 slots but put just one tape in one of the slots, if you wish. In fact, you should leave some slots empty in case if you need to restore without interrupting current backups.
Best regards,
John Smith
Cristalink Support

shermaine
Posts: 3
Joined: 06 Apr 2016, 16:13

Re: Best Practice to create the No of tape slot

Post by shermaine » 20 May 2016, 13:18

Thank you, John,
Yes, I restored back 5drive and 200 slot configuration, but I only create 20 virtual tape file on the USB drive.

Last question, will it be better to have a bigger drive or many No of small drive. Like I have 2TB Disk as Tape drive, when create media file, it is good to make it 10 Drive @ 200G each, or 20 drive @ 100G each?

Many thanks again

jsf
Cristalink Support
Posts: 300
Joined: 29 Aug 2010, 09:03

Re: Best Practice to create the No of tape slot

Post by jsf » 21 May 2016, 02:06

Last question, will it be better to have a bigger drive or many No of small drive. Like I have 2TB Disk as Tape drive, when create media file, it is good to make it 10 Drive @ 200G each, or 20 drive @ 100G each?
Please refer to How many tapes of which sizes should I use?
Best regards,
John Smith
Cristalink Support

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