At Wednesday, 15 December 2004, Alvin Oga <[EMAIL PROTECTED] com> wrote:
>hi ya joao > >On Thu, 16 Dec 2004, Joao Clemente wrote: > >> Image you're using software raid and 1 disk fails. You somehow get >> alerted and , AFAIK, you >> 1 - shutdown the machine (ok, this if you don't have a hot-swap system) >> 2 - remove the failed disk >> 3 - insert a new, "fresh-from-the-store" disk > >for sanity ... i always fdisk the new disk to be the same as the >remaining disk > >> 4 - power-up > >and sw raid will mirror the good disk onto the new disk > >depending on size of your disk ( data ), it can take a day .. > >if you continue to write data, while is mirroring, yo risk losing >everything ... > >if the idea of mirroring was so that you can operate, 24x7x365, >than you should be using a complete server in NYC and a complete server >in LA ... > >having 2 disks on one system is an oxymoronic way to (try) guarantee >24x7x365 operation with zero downtime > >IDE is NOT hot swappable > >SATA disk tries to be hotswappable by looking like a scsi disk ... > >SCA scsi disks is hot swappable but is NOT cheap in terms of >the same sized 1TB of 4x 300GB ( $300ea ) IDE disk array >vs lots of expensive hotswap scsi disks to create 1TB of space > >> Now, if this was a hardware raid solution, yes I believe the array will >> self-contruct again. > >sw raid, when PROPERLY created will also resysnc/self-construct >again all by itself > >> My question is if, with these steps you'll have a >> software RAID system resync'ing the array... or you need to do extra >> steps like: > >no extra step is supposed to be needed except to take the old >disk out and plug in a new one > - power down would depend on if its ide or sata or scsi > and how the disk is mounted > >> 5 - partition the disk with same partition layout as the removed one > >probably a good idea ... to keep it the same as before >even if your enw disk is bigger than before > - use the xtra (unused) space for something else > >> and only after this step the array can re-construct .. What's your >> experience on this? > >no problems with sw raid .. > >hw raid isn't worth a penny .. ie .. throw it away .. > >but if you got a real raid controller for say $10K or $20K >where that's all the company makes is raid controllers, than >those hw raid controllers does work as advertized >- pc/pci based hw raid is a disaster waiting to happen > > - hopefaully data is backed up > on other systems where last weeks data is NOT > overwritten by this weeks suspect/corrupt new data > which you find out is corrupted 2 weeks in the future > >c ya >alvin > >-- >To UNSUBSCRIBE, email to [EMAIL PROTECTED] >with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED] debian.org > it's all so confusing. ---------------------------------------------------------------------- Zero Crossings, Inc. -- Embedded and Digital Signal Processing Systems http://www.zerocrossings.com/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
