Boston Linux & UNIX was originally founded in 1994 as part of The Boston Computer Society. We meet on the third Wednesday of each month at the Massachusetts Institute of Technology, in Building E51.

BLU Discuss list archive


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss] Gluster startup, small-files performance



F. O. Ozbek wrote:
> If you lose power to your entire storage cluster, you will lose
> some data, this is true on almost all filesystems.(including moosefs and
> glusterfs)

If writes are atomic -- that is, the file system driver and underlying
hardware honor fsync calls -- then you won't lose anything that's been
completed because all completed writes have been committed to
non-volatile storage. You will lose incomplete writes but the clients
will know it (fsync calls time out or return errors) and can retry or
invoke error handlers.


> It is possible to setup a moosefs cluster with redundant metadata
> servers in separate locations (and chunk servers in separate locations.)

A catastrophic failure at the wrong time (is there ever a right time?)
will leave you with lost or corrupted data no matter how many parallel
storage clusters you have.


> This will save you from power outages as long as you don't lose power
> in all the locations at the same time. Keep in mind these servers
> are in racks with UPS units and generator backups.

So are Amazon's EC2 racks. Yet:
http://www.zdnet.com/amazon-web-services-suffers-outage-takes-down-vine-instagram-flipboard-with-it-7000019842/
http://venturebeat.com/2012/10/23/amazon-ec2-outage-restored/
http://money.cnn.com/2011/04/21/technology/amazon_server_outage/

-- 
Rich P.



BLU is a member of BostonUserGroups
BLU is a member of BostonUserGroups
We also thank MIT for the use of their facilities.

Valid HTML 4.01! Valid CSS!



Boston Linux & Unix / webmaster@blu.org