Difference between revisions of "OceanStore & GPFS"
Jump to navigation
Jump to search
| Line 16: | Line 16: | ||
=Ocean Store= | =Ocean Store= | ||
Pros | Pros | ||
*Only trust required is own box | |||
*Data is highly durable due to file versioning | |||
*Information divorced from location | |||
**So long as you can reliably obtain information, it doesn't matter where it is located | |||
*Applicable to many data storage situations, not for a specific case | |||
*Routing is decentralized | |||
*2/3 of network is up? All is available | |||
Cons | Cons | ||
*Very expensive to computer cryptography (slow generation of keys) | |||
*Utility models don't make economic sense, people prefer not to pay for access to their data | |||
| Line 35: | Line 32: | ||
Distributed local OS designed for clusters | Distributed local OS designed for clusters | ||
Max size of 4096TB | Max size of 4096TB | ||
Pros | Pros | ||
**Massively parallel - data is striped across many many disks | |||
**Therefor read/write is very fast | |||
*Option of redundancy | |||
*Locking mechanism | |||
**Two options | |||
***Data shipping | |||
****Distributed | |||
****First client to request access to file receives token | |||
****Other clients must request the current owner of the token | |||
*****The current owner of the file grants portional access to their file (breaks token and gives portion access) | |||
***Centralized locking | |||
****Faster in a small disk circumstance | |||
*Extreme reliability | |||
**Able to literally remove a hotswap disk and insert a blank one in its place, only to have the blank disk completely regenerate the missing data | |||
**Journalling to record token ownership - helps recovery when node in possession dies | |||
Cons | Cons | ||
*Everything must be trusted! Designed for clusters, not across LAN/WAN | |||
*Not appropriate for distributed networks. | |||
=XUFS= | =XUFS= | ||
User-space implementation | *User-space implementation | ||
Designed to be simple | *Designed to be simple | ||
Very generic | *Very generic | ||
Revision as of 16:50, 25 February 2008
Readings
John Kubiatowicz et al., "OceanStore: An Architecture for Global-Scale Persistent Storage" (2000)
Sean Rhea et al., "Pond: the OceanStore Prototype" (2003)
Questions
Is it worth it??
Ocean Store
Pros
- Only trust required is own box
- Data is highly durable due to file versioning
- Information divorced from location
- So long as you can reliably obtain information, it doesn't matter where it is located
- Applicable to many data storage situations, not for a specific case
- Routing is decentralized
- 2/3 of network is up? All is available
Cons
- Very expensive to computer cryptography (slow generation of keys)
- Utility models don't make economic sense, people prefer not to pay for access to their data
GPFS
Distributed local OS designed for clusters Max size of 4096TB
Pros
- Massively parallel - data is striped across many many disks
- Therefor read/write is very fast
- Option of redundancy
- Locking mechanism
- Two options
- Data shipping
- Distributed
- First client to request access to file receives token
- Other clients must request the current owner of the token
- The current owner of the file grants portional access to their file (breaks token and gives portion access)
- Centralized locking
- Faster in a small disk circumstance
- Data shipping
- Two options
- Extreme reliability
- Able to literally remove a hotswap disk and insert a blank one in its place, only to have the blank disk completely regenerate the missing data
- Journalling to record token ownership - helps recovery when node in possession dies
Cons
- Everything must be trusted! Designed for clusters, not across LAN/WAN
- Not appropriate for distributed networks.
XUFS
- User-space implementation
- Designed to be simple
- Very generic