Wiki Home Disk Manager Disk Cache Settings and Recommend

Disk Cache Settings and Recommend

2016/05/09 12:25

Notice: This wiki is for the old version CCBoot. Please click HERE to access the new version wiki

To access the disk cache settings click the “Disk Cache” icon on the CCBoot interface (see Figure 1‑1).

disk-cache-0-1-1

Figure 1‑1

On the “Disk Cache” window, click “Add” button to add Image/Game disk (as seen in Figure 1‑2).

Figure 1‑2

When you add disk in Disk Cache.There are some parameters related to cache (Figure 1‑2).

RAM Cache: Define the RAM memory size for the disk cache.
SSD Cache: Define the SSD size for the disk secondary cache.
SSD Cache Drive: Enable this check box to enable SSD cache for your disks.

CCBoot always uses RAM cache as the first cache storage, and the SSD cache is as the second cache storage. So when CCBoot receives the read requests from the client, it will search it in RAM cache firstly and then SSD cache. If found, it will read the data from the cache else read data from the physical disk directly.

1 RAM Cache

1.1 Ram Cache Recommendation

Server Physical RAM	Image Cache	Game Cache	Writeback Cache
4 G	512 M	1024 M	512 M
8 G	1024 - 2048 M	3072 - 4096 M	1024 M
16 G	2048 – 4096 M	5120 – 8192 M	1024 - 2048 M
32 G	2048 – 4096 M	8192 – 25600 M	2048 – 4096 M

In fact, 1 G RAM for image cache is enough. Though the image file size is over 1 G. But the most frequently read data of image at client is less 1 G. Notes: Its good practice to leave 2- 4 G RAM for server OS system.

Suppose the CCBoot server has 8 GB of physical RAM, the recommended cache settings are as below.

1.2 Image Cache

Although image disk have big size, less than 1 GB of data is read so there is no need to have huge RAM cache for Image Disks

Enter desired amount of RAM for Image disk.

You can set Writeback cache from 512 MB – 2048 MB, depending on the RAM available on the server

Figure 1‑3

1.3 Game Disk Cache

Game disks have a lot of reads and writes so to cache much of it, we set a large portion of RAM for Game disk cache.

Enter desired amount of RAM for Game disk.

You can set Writeback cache from 2048 MB – 25600 MB, depending on the RAM available on the server.

Figure 1‑4

1.4 Writeback Disk Cache

Enter desired amount of RAM for Writeback disk.

You can set Writeback cache form 512 MB – 4096 MB, depending on the RAM available on the server.

Figure 1‑5

1.5 Final Disk Caches

Here only 5 GB of RAM is allocated for RAM Cache, remaining 3 GB of the 8 GB RAM is left for Window OS usage. You should never set RAM Cache to user more than 80% of RAM if your RAM is less than 16 GB on the Server.

Figure 1‑6

2. SSD Cache

If you have an SSD disk, we recommend you to enable the SSD cache function of CCBoot. SSD cache is almost used for game disk cache, which can bring you a better performance. It will speed up client games loading. We recommend you to format the SSD as one drive.Normally, we only recommend to set SSD cache for game disk. RAM cache is enough for Writeback Disk so it does not have SSD Cache (in newer version of CCBoot).

How to define the SSD Cache size?

Normally, we use the almost size of the SSD disk as the SSD cache and left 10% size. For example, if the SSD disk size is 80 G, we use 80 * 90% = 72 G as the SSD cache size. DO NOT use full size of SSD disk for the SSD cache. Because when the SSD disk is full, the performance will be reduced much more.

SSD Disk Size	Game SSD Cache
80 G	7168 M
120 G	102400 M

SSD Cache Drive

On CCBoot server, in the "Disk Cache" window tick the “SSD Cache Drive” check box (as in Figure 2‑1).

Figure 2‑1

2.1 SSD Image Disk Cache

For image disk 4096 MB SSD Cache is enough, but if your image is very large (say, 30 GB or more), set the cache 4096 - 8192 MB,depending on the available space on your SSD Drive.

Figure 2‑2

2.2 SSD Game Disk Cache

For Game disk set about 70% of SSD Drive size as SSD Cache.All the read files are cached on SSD drive and will speedup game loading on clients as reading from SSD Cache is faster than on traditional HDD.