Using the device node file names such as /dev/sda isn't encouraged because the device mappings may not persist across reboots. For instance, /dev/sda might be enumerated to /dev/sdb upon reboot then you're in all kinds of trouble and this why one must setup multi-pathing and reference the device names as /dev/mapper/<device>. -----Original Message----- From: redhat-list-bounces@xxxxxxxxxx [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of raj sourabh Sent: Tuesday, 7 December 2010 5:04 p.m. To: General Red Hat Linux discussion list Subject: Re: Disk mapping for oracle ASM (Matty Sarro) Hi Matt, Correct.. Its better to check it whether oracleasm service affects the DB :) However in all my current deployments I have used raw devices .. I have another doubt in this regard(may sound silly).. but Why can't the direct devices (soft links .. eg /dev/sdc, /dev/sdd) could be used for asm disks..???? Regards, Raj On Mon, Dec 6, 2010 at 8:07 PM, Matty Sarro <msarro@xxxxxxxxx> wrote: > Please correct me if I am wrong, but I think you may be confusing the the > kernel library used to access the disks and the separate utilities used to > manage/configure the disks. They're separate things :) The management > utility marks the disks to be read/written to by the library, so it can die > and you should still have no problem accessing your data. Sort of like > fdisk > could die, but you'd still be able to access your SATA and IDE drives > without any problem. It'd be easy to play with if you have a few minutes; > just kill the ASM service and see if your db dies or not :) I think you'll > be pleasantly surprised. Again, this is just with my cursory knowledge of > ASM so I could be wrong. > -Matty > > > On Mon, Dec 6, 2010 at 1:45 AM, raj sourabh <rajsourabh1@xxxxxxxxx> wrote: > > > Hi, > > > > Thanks for the information. > > > > But dont you think if oracleasm deamon/service is hung or stoppedon > > nodes then your whole database comes down. This was't the case with raw > > devices. Even though there is entry for it in /etc/init.d/rawdevices but > in > > RHEL 5.5 you can not stop or start it :) > > > > Regards, > > > > Raj > > > > On Mon, Dec 6, 2010 at 6:35 AM, Yong Huang <yong321@xxxxxxxxx> wrote: > > > > > Regarding kernel upgrade and ASMlib upgrade, there may be an annoyance > > > to some people finding the correct ASMlib on Oracle OTN web site. It's > > > better to always go to > > > > www.oracle.com/technetwork/topics/linux/index-101839.html#oracleasm_2_0 > > > instead of search at otn.oracle.com. The search result may list > multiple > > > pages that appear to have the libraries. But the first link points to > > > a page that may be missing the libraries while the page I showed above > > > has it. > > > > > > Once you installed with rpm, do: > > > /etc/init.d/oracleasm enable > > > > > > ASM is the future. Raw is deprecated. > > > > > > Yong Huang > > > > > > > > > > > > > > > -- > > > redhat-list mailing list > > > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > > > https://www.redhat.com/mailman/listinfo/redhat-list > > > > > -- > > redhat-list mailing list > > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > > https://www.redhat.com/mailman/listinfo/redhat-list > > > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list > -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list ========================================================== For more information on the Television New Zealand Group, visit us online at tvnz.co.nz ========================================================== CAUTION: This e-mail and any attachment(s) contain information that is intended to be read only by the named recipient(s). This information is not to be used or stored by any other person and/or organisation. -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
