(Illustration by Gaich Muramatsu)
On Wed, Apr 27, 2005 at 08:26:15AM -0600, Patrick Walsh wrote: > One thing that I'd also like to see -- maybe its place is on the wiki > -- is a list of Coda's constraints. How many files in a directory can > coda handle, what are the limitations when working with big files, etc. Some of these I know, but there are probably many I don't even know. volume names: 32 characters file names: 256 characters path names: 1024 characters ACLs per directory: 20 - Don't know why I always thought it was 6 directory size: 256KB - this doesn't easily translate to # of files, because it depends on the average filename size, padding, space for the file identifiers, etc. a ballpark figure would be between 2048 and 4096 files. volumes/server: 1024 replicas/volume: 8 users and groups: unknown, I tried several thousand users/group: unknown, at least several thousand as well - Here is a CVS commit message related to that, 2003/06/17 20:39:23 <jaharkes_at_cs.cmu.edu> Caching the rwcdb handle across accesses. Time to import 5000 users and a group containing all users went (on my laptop) from 21+ minutes to 11.621 seconds. The 100,000 user test is taking a lot longer to import but checking group membership as the import is still going directories/volume: Depends on the size of the volume resolution log - We use one 'ResolveNull' entry for each directory. resolution log: Administrative limit - By default a volume has 4096 entries, but this can be increased with 'volutil setlogparms <volid> reson 4 logsize <n>'. files/volume: Unknown - not as simple as (files/directory * directories/volume) because at some point we have trouble finding enough unfragmented RVM memory to allocate the flat lookup table. I think RVM allocation issues hit around 200,000 files/volume, but I could be wrong. servers/realm: 253 - We need unique server-id's in the range [0:255]. But 0, 127, and 255 are 'reserved' to indicate 'no volume, replicated volume, and error'. rvm data/server: anywhere between 1GB and 3GB - depends on where the OS loads it's shared libraries and such. ... probably many more JanReceived on 2005-04-27 14:48:02