02-20-2019 12:14 PM
Just curious what type of performance people are seeing when backing up virtual machines with LTO 7 (FC) drives on a 1Gb network. The highest transfer/backup rate I see is around 2GB/minute which seems slow since I can copy files across the network at much higher rates. Full backups are much faster in every case where as incrementals are usually half as slow as a full backup.
One odd case is a file based backup that for whatever reason runs at 5-6GB/min. No idea why that one is so fast compared to everything else. All servers are on the same network and use the same connections/devices. Would love it if all backups went that quickly.
02-21-2019 04:10 AM
the fastet Backup you get over a 1GB Link will be about 7GB/min (113MB/s).
For a Hyper-V backup without GRT you get 6.5 - 7GB /min.
For a file server with millions of small files it´s about 1GB/min.
With these speeds you get your LTO 7 shoe shining .
You need to get all data to a local disc that has a raw transfer rate of 300 MB/s (10k/rpm or SSD).
Then just duplicate to tape.
02-21-2019 04:52 AM
The speeds we see are much slower when doing a VMware VM backup. Full backup jobs run at about 1.8GB/min while the incremental jobs run at about 450MB/min to 650MB/min.
We have no file servers with millions of files. Most of the systems are just regular operating systems with basic services/applications.
02-21-2019 05:28 AM
first step. Don´t Backup to Tape !
Use a local disk an get some backup2disk jobs for the VM´s
If these backup don´t run with about 5-6GB/min there must be some other problems with your VMWare host.
And disable GRT for this test.
Try to do a bare file copy from VM Host to backup server, this schould give you 112MB/s.
If not there is something wrong with your servers.
Was it fast in the last month or is this always slow.
02-22-2019 10:06 AM
If you are using traditional mechanical hard drives in the source server, you will see a slowdown when accessing small files. This is caused by head-arm cylinder seek and rotational disk delays getting the correct sector under the head as it transitions from one file to the next.
For SSD based file server storage there is no seek delay, so I would expect a more constant transfer speed for large and small files.
LTO7 will vary the tape speed based on the input, and has a maximum raw hardware stream rate of 300 megabytes/second, 18 gigabytes/minute uncompressed, if nothing else is bottlenecking it.