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How to efficiently balance savesets from one client to library tape drives ?
Hello,
I have the following scenario with Networker 7.6.2 and a tape library with two drives:
There is one large group, containing about 15 backup clients. Out of those clients there is one particluarly large file server with 4 SAN LUNs attached ( on same kind of storage).
The full backup time for the first three LUNs( having about 1TB) is about 15 hours, which is acceptable for our business.
However, the weekend full backup for the 4th LUN(4TB) takes more than 50 hours, thus extending into business hours.
I have decreased the Priority setting for this particular client and its savesets start first, still this is not enough.
I am thinking to split the single location (available on the 4 TB LUN) into multiple savesets and balance these savesets across the two library drives.
I would achieve this by manually entering all subfolders from the main location into the Networker client setup and manually create an empty folder on the filesystem, so that Networker would not backup the root location from one job.
Would this speed up my backup for this client ?
Also, I was looking for a way to split the multiple savesets on the 4TB LUN across the two library drives.
I was thinking to use the targets feature on the two drives, but as there are about a dozen backup clients (big and small with multiple savesets each), I have no guarantee that the split savesets of the 4TB LUN would be backed up on different drives.
Does anyone have a better solution for this ?
Please let me know if additional details are needed.
Thanks and regards,
Bogdan
mridul_singh
57 Posts
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August 13th, 2012 07:00
Ideally this should not happen. When you split the save sets, NetWorker will back up everything specified in the individual folders, unless you have mount point, nested file systems or DFS-R. Nevertheless, you may split the save sets the way it works for you. If you are not allowed to create multiple groups, you can still split the client into multiple instances and then, put then in the same group.
Then you need to check how many session will be running at a time, in addition to the client in question and then you can set the target session accordingly on the drives.
For example, suppose you split the problematic client in 10 subfolders and all the 10 are running at the same time. This will create 5 sessions for each drive. Now if the other backups make say 10 session at a time, you should set target session to somewhere 15-18, and max target sessions to 20-24. You will need to monitor the backup behavior and tune accordingly.
Hope this helps.
mridul_singh
57 Posts
0
August 13th, 2012 07:00
Hi,
Probably splitting the file system would be the best way to tackle this. What i could think of is, breaking the filesystem in to subfolders, such that each subfolder ends up having more or less the same size and same number of files.
for eg: split the data into 4 subfolders with 1 TB each and say approx 1 million files( This could vary depending on actual files)
Once you have decided how many subfolder you want to create than, do the follwoing
1. Create multiple instance for the client, each with the subfolders as saveset
Cange the client ||sm to match the number of savesets prsent in the client definition.
2. Create different groups for each of the above created clients.
3. Change the target session on the devices to a higher number( The number of sessions you wish to be written simultaneously on each drive)
4. Ensure that both the drives are avilable for writing the backup simultaneously
The backup rate will also depend upon the type of tape drive you are using. Further to reduce the backup window, you may also schedule the splitted backup groups with some time gap so that there is not a lot of read lag from the disk.
I am not sure, why you need to create a empty file system for this.
Bogdanionut_bad
27 Posts
0
August 13th, 2012 07:00
Hi Mridul,
Thanks for your quick reply.
I have noticed that for example if I try to backup location D:\ with folders X,Y,Z and I insert D:\X, D:\Y, D:\Z in the backup client, Networker only backs up the common root path D:\.
I was thinking to create an empty file W:\, so that then I could backup three savesets D:\X, D:\Y, D:\Z indicidually as opposed to the common root path.
Also, I have a few questions about your recommendations:
1. How can I be sure that the savesets (within one backup client) can be evenly distributed on the two drives ? I have more backup clients running in the same group, and multiple groups in the same pool. Sessions from other backup clients will be taken into account by the Targets parameter.
2. Due to internal regulations, I am somehow restricted from creating additional backup groups. Would splitting the D:\drive into multiple savesets, as mentioned above bring any benefit ?
Thanks,
Bogdan
Bogdanionut_bad
27 Posts
0
August 13th, 2012 23:00
Thanks for the help, Mridul