Top 8 Things That Are Slowing Your Backups Down

Why is my backup taking so long? Have you ever been to such a situation? If yes, then it is time to find out what causes the slowing down of your data backups and how to make your backup environment more efficient?

There are times bottlenecks occur between the data and backup devices. This happens when the backup throughput required to complete the process is larger when compared to the network bandwidth. Why bottlenecks occur and how to alleviate them? The solution is to increase the bandwidth between the data and backup devices to slow down data backups that are caused by bottlenecks.

On a typical system, data backup is the closest thing to simple read-write operation. Something happens to your backup; it will affect your everyday operations. If your backups abruptly start to take longer, examine your system even if the backups are still within your normal backup window.

Why Is Backup Taking So Long?

Let us have a look at the checklist of 8 things that causes slow data backups:

1. Speed Discrepancy

How does your system transfer data? Faster or slower? Yes, speed matters. If your system is feeding/ transferring data faster or slower than your backup system can handle it, then that will affect the backup performance. A slower speed indicates lesser throughput. Trying to feed data too fast results in blocks being resent. Thus, adjust both the speeds such that they match with each other.

2. Improper Parameters

After speed, it is incorrect parameters for the storage that can make backup systems slow down your backups significantly. The classic one does not have enough cache, but there are several other potential problems as well. This includes incorrect host bus adapter (HBA) settings, poor choice of page file parameters or block sizes, or the wrong SCSI settings. Check the documentation (including any new updates on the manufacturer’s Web site) to ensure everything is set correctly.

3. The Wrong Firmware

Ensure you have got the appropriate firmware on your system. Here “appropriate” means the latest version, but not always. In case your backup performance deteriorates after a new version of the firmware on any part of your system, then check with the manufacturers. Else try switching back to the old version and check the performance improvement.

4. Media Failures

The lifespan of backup media is finite; thus, you need to replace disks and tapes as and when required. When it comes to tapes, its lifespan is determined by how long they have been used or the number of backups. In the case of hard drives, the procedure is to wait until the disk starts showing indications of impending failure.

Dirty heads are also one of the reasons for reads and write to fail on tape systems. Ensure that you clean the heads on your tape drives and libraries as per the manufacturer’s instructions. (For instance, do not clean DLT drives until the cleaning light on the device is on.)

Both tape and disk are remarkably resilient, and both will try to work by rewriting failed blocks even as they are failing. However, that takes time, and failing media can cause backups to slow down significantly. As failing media makes the backup unreliable, the best option is to replace media on a regular schedule or during the first sign of failure.

5. Network Issues

When you back up over a network, even the network performance has a major impact on backups. It is better to ensure that you have got enough bandwidth to handle both the backups and traffic if any on the network at the same time. A failing network component or a bad connection is also one more reason behind the slowdown of the backup. Any problems related to the network will usually show up in the network logs. These logs will give you clues to poor performance, especially if the problem is intermittent or comes on suddenly.

6. Backing Up Wrong Stuff

To avoid such situations use data deduplication on you your files before backing them up. Around 90 percent of the stuff on some systems do not need to be backed up, especially when you have features like System Restore on Windows systems to handle immediate recovery of lost files and folders. When you backup things like .tmp files and browser caches, you end up wasting backup time. Modern backup software will allow you to apply elaborate filters to determine what is getting backed up and what is overlooked.

7. Inappropriate Technology

Nowadays, all backup technologies have their niches, some try to use one outside its niche increases the chances for failure. Pushing a technology beyond its performance level is the root cause of this problem. Technologies like tape technologies, network technologies, and the associated software have a basic range (scale) where they work best. Instant these technologies move outside that scale; they work less and fail.

When we think of backups, we tend to think first of tape drives. For instance, if you are trying to back up, say 300 GB of data on tapes with a capacity of 3.5 GB – it’s going to go slow, no matter how extensive your tape library is. Similar situations are common. Such things happen, usually, for one of two reasons. It might happen that someone made a mistake in specifying the original equipment and chose a technology that was not right for the job. Another more common situation is that your backup needs might have outgrown the technology you are using.

However, the situation is not constantly that clear, especially when the problem is just beginning to surface. Thus, check your performance logs and review your hardware and software specifications when there is a slowdown in backups.

8. Fragmented disks

Severely fragmented disks also cause slow reads and write, and one of the places this shows up is on backup. It is likely to show up first on backup due to a large number of disk operations concentrated in a backup.


Data loss is occurring each and every time. Therefore, it is essential for us to make constant and up-to-date data backup at regular intervals. If you are looking for a comprehensive data backup solution for your vital data, then go for Zmanda. Our backup and disaster recovery solution will ensure your data is safe and will keep your business up and running!

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