Two more parameters, from DroboDashboard:
IOPS to backup program = ~450-520
Read Throughput to backup = 20-24MB/sec
In comparison, for a single HD stream:
IOPS for video = 20-22
Read and Write throughput = 1MB/sec
So I may have understated the backup share of the 28MB/sec stuttering situation in the prior message.
Sure, it would be cool if the backup program had a throughput or priority adjustment, but that means finding a new program. Is the the best performance I should expect?
I’ve come to accept that 20-24B/sec write may be all I should expect.
I’ve come upon a new problem. When my Media Center has to reboot, it takes 15 minutes for the Drobo to mount. I’m not talking about a power failure, I have a UPS. I’m talking about a safe shutdown via Windows followed by a restart. I can’t even get the Drobo program to open during this time.
I have three potential theories, and I’m looking for a recommendation:
I shouldn’t have set “high performance” write caching in Windows, because that causes some fsck (or the Windows equivalent) on a reboot.
The problem is Windows Backup/Restore, for which I have a separate Backup partition set up. The Knowledge Base hints this at http://support.drobo.com/app/answers/detail/a_id/163 , though I thought the whole purpose of the new “backup partition” feature was to make this sort of thing work.
The Drobo is doing something that takes forever. This isn’t indicated on the LEDs, all are solid green and there is about the space I’m expecting.
It just takes a long time to do any sort of experiment, and most of the time there aren’t any symptoms.
It is Gen3 Drobo with 4 Seagate NAS 3TB drives. 5 blue LEDs full. As you know, there is no “off” command for WMC. As a result, I can’t dismount the drive with the Drobo application because it’s always still in use. When I shutdown the system, waiting until the Drobo power LED is yellow, and then restart it the Drobo does not mount or respond to the Drobo appplication for 17 minutes.
17 mins is long enough that WMC has given up waiting for the device to mount, and purged it from the list of storage locations. When it finally comes online, recordings are impacted for another 4-5 minutes while WMC reads all the file statis back in to rebuild its directory.
What’s the Drobo doing, and why doesn’t the filesystem show as clean after a reboot? Should I reformat the Drobo as all “backup” volume, so that the Windows file system is used rather than the Drobo one? This seems like a huge step backwards, but this device isn’t really working in the WMC application.
when you have a moment, if you can see the drobos drive letter in My Computer ,can you let me know what does the max size show? that is the actual volume size that i was wondering about.
for your newest issue maybe there is a way to shut down wmc, just before powering down computer and drobo but it might be useful if you can get Process Explorer and to run it as admin and search for the Drive Letter of your drobo under search for dll/handle button. maybe some details can be found there?
that will show a list of programs which are currently locking/accessing the drobo.
some are windows related, such as recycling bin etc, but sometimes when im unable to shutdown a drobo via dashboard, i run it and find a hanging handle/process which i can then close and it shuts down.
