mattlach
Patron
- Joined
- Oct 14, 2012
- Messages
- 280
Hey all,
The guide suggests checking with zilstat.
I loaded up a worst case write load of 6 simultaneous HD recordings (MythTV writes to my FreeNAS box) as well as some other miscellaneous writes that might be going on at the same time.
Problem is, I don't fully understand the output, and when a dedicated ZIL would be appropriate, and really don't know if these writes are synchronous or not (one would think writing large mpeg files would be sequential, but you never know)
I'm trying to solve an issue where there is skipping when I record and playback the same show at the same time (like time shifting with a DVR)
Here are my results:
Do you guys think this type of ZIL load would benefit from a dedicated SSD mirror?
If so, what are you people using these days? People used to recommend Intel's small SLC SSD's, but I'm not sure if that is the case anymore. Based on write endurance Samsungs new 850 Pro's look like they might be up to the task, but the smallest ones are 128GB, which might be overkill?
I'd appreciate any input.
Thanks,
Matt
The guide suggests checking with zilstat.
I loaded up a worst case write load of 6 simultaneous HD recordings (MythTV writes to my FreeNAS box) as well as some other miscellaneous writes that might be going on at the same time.
Problem is, I don't fully understand the output, and when a dedicated ZIL would be appropriate, and really don't know if these writes are synchronous or not (one would think writing large mpeg files would be sequential, but you never know)
I'm trying to solve an issue where there is skipping when I record and playback the same show at the same time (like time shifting with a DVR)
Here are my results:
Code:
~# zilstat -t 60 TIME N-Bytes N-Bytes/s N-Max-Rate B-Bytes B-Bytes/s B-Max-Rate ops <=4kB 4-32kB >=32kB 2014 Aug 1 13:18:25 623499720 10391662 15626184 665583616 11093060 16515072 5078 0 0 5078 2014 Aug 1 13:19:25 645754864 10762581 17978008 689569792 11492829 19005440 5261 0 0 5261 2014 Aug 1 13:20:25 642361064 10706017 20112744 684982272 11416371 21233664 5226 0 0 5226 2014 Aug 1 13:21:25 686078704 11434645 26390584 730857472 12180957 27656192 5576 0 0 5576 2014 Aug 1 13:22:25 679570784 11326179 22014712 722337792 12038963 23068672 5511 0 0 5511 2014 Aug 1 13:23:25 675923976 11265399 19917552 721420288 12023671 20971520 5504 0 0 5504 2014 Aug 1 13:24:25 670082856 11168047 19491296 714997760 11916629 20578304 5455 0 0 5455 2014 Aug 1 13:25:25 649737784 10828963 18799480 693370880 11556181 19660800 5290 0 0 5290 2014 Aug 1 13:26:25 665050672 11084177 23619464 710279168 11837986 24772608 5419 0 0 5419 2014 Aug 1 13:27:25 624072240 10401204 15810544 668467200 11141120 16777216 5100 0 0 5100 2014 Aug 1 13:28:25 669554104 11159235 19915792 766435328 12773922 21102592 5964 0 108 5856 2014 Aug 1 13:29:25 640427920 10673798 15437024 698683392 11644723 16515072 5347 0 15 5332 2014 Aug 1 13:30:25 955904680 15931744 46549680 1011351552 16855859 48627712 7716 0 0 7716 2014 Aug 1 13:31:25 857059392 14284323 37336736 919687168 15328119 39059456 7075 0 62 7013 2014 Aug 1 13:32:25 876726880 14612114 38173368 931528704 15525478 40239104 7107 0 0 7107 2014 Aug 1 13:33:25 711064344 11851072 29610680 759697408 12661623 31195136 5797 1 0 5796 2014 Aug 1 13:34:25 594192792 9903213 19124552 651833344 10863889 20054016 5111 0 149 4962 2014 Aug 1 13:35:25 661954072 11032567 21622656 708837376 11813956 22806528 5408 0 0 5408 2014 Aug 1 13:36:25 643512888 10725214 18260032 689045504 11484091 19398656 5257 0 0 5257 2014 Aug 1 13:37:25 644810520 10746842 18329992 689442816 11490713 19136512 5261 1 0 5260 2014 Aug 1 13:38:25 672630288 11210504 19905648 716701696 11945028 20971520 5468 0 0 5468
Do you guys think this type of ZIL load would benefit from a dedicated SSD mirror?
If so, what are you people using these days? People used to recommend Intel's small SLC SSD's, but I'm not sure if that is the case anymore. Based on write endurance Samsungs new 850 Pro's look like they might be up to the task, but the smallest ones are 128GB, which might be overkill?
I'd appreciate any input.
Thanks,
Matt