Timeshift file configuration (1 Viewer)

[mm1352000]

I assume I will need to manually calculate max# files x size of files + overhead to make sure this variable is not larger than my ram drive???

Nope. As mentioned above, TV Server will prevent you from using the last [Filesize] on your drive no matter what. If I were you, I would set [Maximum] >= ([Size of RAM drive] / [Filesize]). I'd set [Minimum] = [Maximum] as well. That will ensure that TV Server will use the space on your RAM drive to the fullest extent possible. The one thing it doesn't do is force the space to be shared evenly between multiple clients.

 

[kiwijunglist]

ok thanks for spending the time to explain it all, I think I understand it all now.

I think the best setting would be

Set Minimun to ( Size of Ram Drive - Overhead ) / file size
Set Maximinum to twice the minimun (ie double the size of the ram drive) ??????

 

[kiwijunglist]

Ram Drive    |  #Clients  |  File Size  |  #Minimum  |  #Maximum
 
1024mb          1            120mb          X          X
1024mb          2            120mb          X          X
 
2048mb          1            120mb          X          X
2048mb          2            120mb          X          X
2048mb          3            120mb          X          X
2048mb          4            120mb          X          X
 
4096mb          1            250mb          X          X
4096mb          2            250mb          X          X
4096mb          3            250mb          X          X
4096mb          4            250mb          X          X
 
6144mb          1            250mb          X          X
6144mb          2            250mb          X          X
6144mb          3            250mb          X          X
6144mb          4            250mb          X          X
6144mb          5            250mb          X          X
 
8192mb          1            250mb          X          X
8192mb          2            250mb          X          X
8192mb          3            250mb          X          X
8192mb          4            250mb          X          X
8192mb          5            250mb          X          X
8192mb          6            250mb          X          X

If we could decide on ideal settings for most people then a table like this in the wiki would probably make things easier for most users.

If you can get me started on maybe the first 6 entries so I see the pattern I can complete the rest and add it to the wiki

 

[mm1352000]

If we could decide on ideal settings for most people then a table like this in the wiki would probably make things easier for most users.

If you can get me started on maybe the first 6 entries so I see the pattern I can complete the rest and add it to the wiki

IMO there is not a right or wrong answer here. Yes, you're limited by how many clients you have and how much disk space you have, but within that... you have the freedom to choose what suits you best. So I don't think I agree with the premise that you're starting from, but I've tried to ignore that and filled in the table below with the following assumptions:

1. That a person wants the maximal amount of back buffer achievable with the given drive size.
2. That the number of clients are the number of people simultaneously using the TV Server for timeshifting.
3. That a person wants to share the drive size as evenly as possible between the clients.

Minimum = maximum due to assumption 1, so I've removed that column.
I've added "wasted space", which is effectively the amount of space that TV Server can't use because of assumptions 1 and 3 (ie. perfectly even sharing, not first-in-first-served). It does *not* include the amount that TV Server will refuse to use which is always equal to filesize. Obviously, the smaller the filesize, the more space that can be used.

Ram Drive    |  #Clients  |  File Size  |  #Minimum  |  Wasted Space
 
1024MB          1            128MB          7          0
1024MB          2            128MB          3          128MB
 
2048MB          1            128MB          15        0
2048MB          2            128MB          7          128MB
2048MB          3            128MB          5          0
2048MB          4            128MB          3          384MB
 
4096MB          1            256MB          15        0
4096MB          2            256MB          7          256MB
4096MB          3            256MB          5          0
4096MB          4            256MB          3          768MB
 
6144MB          1            256MB          23        0
6144MB          2            256MB          11        256MB
6144MB          3            256MB          7          512MB
6144MB          4            256MB          5          768MB
6144MB          5            256MB          4          768MB
 
8192MB          1            256MB          31        0
8192MB          2            256MB          15        256MB
8192MB          3            256MB          10        256MB
8192MB          4            256MB          7          768MB
8192MB          5            256MB          6          256MB
8192MB          6            256MB          5          256MB

In the cases above where "wasted space" is non-zero, one could modify the filesize slightly to attempt to use the space better as follows:

Ram Drive    |  #Clients  |  File Size  |  #Minimum  |  Wasted Space
 
1024MB          2            113MB          4          7MB
 
2048MB          2            120MB          8          8MB
2048MB          4            120MB          4          8MB
 
4096MB          2            240MB          8          16MB
4096MB          4            240MB          4          16MB
 
6144MB          2            245MB          12        19MB
6144MB          3            245MB          8          19MB
6144MB          4            245MB          6          19MB
6144MB          5            236MB          5          8MB
 
8192MB          2            248MB          16        8MB
8192MB          3            264MB          10        8MB
8192MB          4            248MB          8          8MB
8192MB          5            264MB          6          8MB
8192MB          6            264MB          5          8MB

The general rule is [Disk Space] - [Filesize] >= [# Clients] * [Filesize] * [Minimum].

To maximise the use of disk space you must minimise the difference between the two sides.
However, you don't want to go too small on the [Filesize] variable as that creates overhead.
I also note that obviously you're not going to get exactly 1024, 2048, 4096, 6144 and 8192 MB available to Windows after partitioning the space, therefore you probably need to deduct half a dozen or so MB from the noted filesize in each case. For example, assuming a 1024 MB RAM disk has actual partition size of 1000 MB, you're going to want to use 125 MB as the filesize.

Is that what you wanted?

 

[kiwijunglist]

Thank you.

I would think people would want more pause buffer than back buffer, I know with my useage I've spent more time using pause that the back buffer, so if that was the case would I use the above table but set max to twice the min setting?[DOUBLEPOST=1350949152][/DOUBLEPOST]

The general rule is [Disk Space] - [Filesize] >= [# Clients] * [Filesize].

This should be [Disk Space] - [Filesize] >= [# Clients] * [Filesize] * [# Minimum] ????

 

[mm1352000]

I would think people would want more pause buffer than back buffer, I know with my useage I've spent more time using pause that the back buffer, so if that was the case would I use the above table but set max to twice the min setting?

I *think* setting min and max to the same value gives you the best possible buffer size in both cases.

Consider the following situation.
You have a 4GB RAM drive and 2 clients.
File size is set to 240 MB.
Assume the ideal where partitoned disk size = physical disk size.
One client starts timeshifting and timeshifts for long enough to fill up their back buffer then pauses.
At some later point, the other client starts timeshifting.

What happens?

If you set min = max = 8:
When client B starts timeshifting half the disk space will still be available regardless of how long client A has been paused. Client A will overwrite their own back buffer when they pause, up until the point when when they finish overwriting the 7th buffer file at which point data will start to be lost. Client A and B share the available disk space as equals, and they have the longest possible back and pause buffers within their allocated space.

If you set min = 8 and max = 16:
When client B starts timeshifting they may not have much of the disk available, depending on how long client A has been paused. Client A can use the whole disk eventually. I'm not certain whether client B can reuse client A's back buffer files, but somehow I doubt it. In other words, client A pausing for long enough *may* prevent client B from starting to timeshift.

If you set min = 4 and max = 8:
When client B starts timeshifting half the disk space will still be available regardless of how long client A has been paused. When paused, client A will create up to 4 new buffer files before overwriting their back buffer.

***Disclaimer: I have not tested the above scenarios. I'm going on code alone, and I could easily be wrong.***

Personally with the given assumptions (in particular, perfect sharing of the disk space) I'm going to go for min = max every time.
Min = 8 + max = 16 seems non-ideal if the clients really are "symetrical" in terms of use. Maybe you could bump the max a little bit (min = 8 + max = 12), but I think every step you bump it up gives more potential for one client to impact on another.
Min = 4 + max = 8 doesn't make much sense to me as it limits the size of the back buffer for no apparent gain.

The general rule is [Disk Space] - [Filesize] >= [# Clients] * [Filesize].

This should be [Disk Space] - [Filesize] >= [# Clients] * [Filesize] * [# Minimum] ????

Yes, you're right - I think I saw that at the same time as you.

 

[kiwijunglist]

ok thanks should I add a table/page to the wiki with suggested settings for filesize/min/max/etc as a "starting point" etc etc. ?

 

[mm1352000]

ok thanks should I add a table/page to the wiki with suggested settings for filesize/min/max/etc as a "starting point" etc etc. ?

If you think it would be helpful then other people are bound to feel the same way, so I would say yes.
Some of the descriptive text and comments about assumptions would probably be helpful as well. Maybe even the example.

 

[kiwijunglist]

Sure I'll try think of something, I'd like to keep things as simple and brief as possible, I could always reference your post in the wiki

 

[kiwijunglist]

http://wiki.team-mediaportal.com/1_...k_for_Timeshifting/Suggested_Ramdisk_Settings

I found ntfs + win7 overhead was about 55mb on my 4096mb ram drive.