On Fri, Sep 19, 2008 at 12:57:25PM -0400, Bill Holland wrote:
> You can use 'mt' to mount a tape, enable diagnostics, and some rudimentary
> testing of the device.
> If you are using ndmp to perform the restore, you can enable debugging
> ('ndmpd debug 70' for max info) to see if there are any issues there.
Yeah. Tape motion works fine. I just wanted to see if I could direct
OnTap to read the tape rather than deal with netbackup.
While netbackup/NDMP is restoring the file, I see very slow reads on
sysstat, but I don't know if that's an NDMP issue or a tape read issue.
> sysstat could be helpful during the restore to try to determine any
> bottlenecks on the filer end. Also, the syslog for any SCSI
>
> Restores will be slower than backups. I don't know the max's for the
> FAS6070, but when we had an R200 we saw that we could run about 200MB/sec
> backups with the CPUs at 100%.
I can't get near that on the LTO-3. I never get faster than 80MB/s.
The restore is around 100 KB/s.
CPU NFS CIFS HTTP Net kB/s Disk kB/s Tape kB/s Cache
in out read write read write age
54% 803 46 0 10642 5422 19045 15465 193 0 >60
18% 224 1 0 1330 5169 13065 13240 193 0 >60
22% 636 0 0 7691 6498 18857 12320 64 0 >60
20% 673 0 0 8540 6608 23073 19397 129 0 >60
29% 501 0 0 7063 5842 14262 29822 64 0 >60
24% 520 105 0 11136 5959 15357 4519 258 0 >60
I'm actually trying to restore a single 100K file. I assume that it has
to read through some of headers at the beginning of the tape, but it was
sure slow doing it.
-- Darren
This archive was generated by hypermail 2b29 : Fri Sep 19 2008 - 13:29:47 EDT