You would have to buy another Auto-changer license to add another Auto-changer but if its being added to the NetWorker server and it already has one you need to consider the following: -
1. Internal bus connections/speed. Which ever way you need to be able to get the data into the NetWorker server over the LAN, through the internal bus and down to the tape drives. All of this requires CPU and bandwidth to be available to get the data to the drives. If you have x drives available already and are going to x + y then you need to ensure the CPU and internal bus can handle driving the tape drives efficiently.
2. Available NICs - 1Gbit NIC speed will give approx 100MB/s of throughput which is enough to drive between 2-3 LTO drives effectively. Unless there is greater bandwidth than this its pointless having more than 3 drives connected.
3. HBA/SAN connectivity to drives - should not be an issue as most HBA speeds are at least 2Gbit (which is usually more than the NIC input) so this tends not to be the bottleneck.
4. SCSI connected drives could possibly limit the throughput but again its probably down to internal bus within the server.
5. It may be better to promote a client or introduce a new server to act as a Storage node and attach the library to this server instead of the NetWorker server. This will also add an additional Storage node license to your costs but could be better for you in the long run.
Its most likely the CPU/internal bus v NIC will be the limiter here, from memory I think you need 12MHz of CPU power for every MB of throughput so you need to do the calculations carefully to ensure you can add this extra hardware and use it as intended. Remember the NetWorker server communicates with its clients and storage nodes over IP so you do not want the NIC over utilised for long periods of time as this could result in NIC throttling and communication issues which could cause backup failures.
OK for LTO4 native they can have a throughput of ~100MB/sec so this would take (100x12)MHz of processing speed which is 1200 MHz. If you plan to add another LTO4 this will mean the CPU needs to be 2400Mhz at least just for drive utilisation. The 12 in the calculation comes form 6MHz for read of data, 6MHz for write for data transfer.
Total MHz required= (((MB-per-sec x num-drives)x6)x2)
CPU required =(Total MHz / processor speed) x 1.25 We times by 1.25 so CUP is not 100% loaded.
Now as stated before this would also need 2 Gbit NIC's to be able to service this. Operating these NIC's will also require CPU power so you could end up with say 4800MHz just for NICS and Drives
So this could translate as a rough guide to 1CPU per LTO and 1Gbit NIC.
masonb
445 Posts
1
June 15th, 2010 02:00
Trekk,
You would have to buy another Auto-changer license to add another Auto-changer but if its being added to the NetWorker server and it already has one you need to consider the following: -
1. Internal bus connections/speed. Which ever way you need to be able to get the data into the NetWorker server over the LAN, through the internal bus and down to the tape drives. All of this requires CPU and bandwidth to be available to get the data to the drives. If you have x drives available already and are going to x + y then you need to ensure the CPU and internal bus can handle driving the tape drives efficiently.
2. Available NICs - 1Gbit NIC speed will give approx 100MB/s of throughput which is enough to drive between 2-3 LTO drives effectively. Unless there is greater bandwidth than this its pointless having more than 3 drives connected.
3. HBA/SAN connectivity to drives - should not be an issue as most HBA speeds are at least 2Gbit (which is usually more than the NIC input) so this tends not to be the bottleneck.
4. SCSI connected drives could possibly limit the throughput but again its probably down to internal bus within the server.
5. It may be better to promote a client or introduce a new server to act as a Storage node and attach the library to this server instead of the NetWorker server. This will also add an additional Storage node license to your costs but could be better for you in the long run.
Its most likely the CPU/internal bus v NIC will be the limiter here, from memory I think you need 12MHz of CPU power for every MB of throughput so you need to do the calculations carefully to ensure you can add this extra hardware and use it as intended. Remember the NetWorker server communicates with its clients and storage nodes over IP so you do not want the NIC over utilised for long periods of time as this could result in NIC throttling and communication issues which could cause backup failures.
Regards,
Bill Mason
Trekk1
1 Rookie
•
48 Posts
0
June 15th, 2010 07:00
There is actually a single LT04 drive in current Autochanger
Fiber Channel drive
Local 15K RPM Raid 5 array for OS and Networker Data
How can I decide if CPU would be enough for this single machine?
masonb
445 Posts
0
June 15th, 2010 08:00
Trekk,
OK for LTO4 native they can have a throughput of ~100MB/sec so this would take (100x12)MHz of processing speed which is 1200 MHz. If you plan to add another LTO4 this will mean the CPU needs to be 2400Mhz at least just for drive utilisation. The 12 in the calculation comes form 6MHz for read of data, 6MHz for write for data transfer.
Total MHz required= (((MB-per-sec x num-drives)x6)x2)
CPU required =(Total MHz / processor speed) x 1.25 We times by 1.25 so CUP is not 100% loaded.
Now as stated before this would also need 2 Gbit NIC's to be able to service this. Operating these NIC's will also require CPU power so you could end up with say 4800MHz just for NICS and Drives
So this could translate as a rough guide to 1CPU per LTO and 1Gbit NIC.
Regards,
Bill Mason