Messages in this thread | | | From | Badari Pulavarty <> | Subject | Re: [patch for playing] Patch to support 4000 disks and maintain backward compatibility | Date | Fri, 11 Apr 2003 08:12:35 -0800 |
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On Friday 11 April 2003 03:09 am, Douglas Gilbert wrote: > Badari Pulavarty wrote: > > Here is my problem.. > > > > #insmod ips.o > > < found 10 disks> > > #insmod qla2300.o > > < found 10 disks> > > #rmmod ips.o > > <removed 10 disks> > > #insmod ips.o > > <found 10 disks - but new names> > > Badari, > In 2.5 lets assume the /dev/sd[a-z][a-z][a-z] > device addressing is left as is (more or less). To > identify lots of disks the Vital Product Data page 0x83 > (failing that, the disk serial number) should be used. > > This information is available via sysfs (thanks to > Patrick Mansfield and Mike Anderson). > > # cd /sys/bus/scsi/devices > # find . -follow -name 'name' -exec cat {} \; -print > SIBM DNES-309170W AJF98887 > ./1:0:4:0/name > SFUJITSU MAM3184MP UKS0P2300CK0 > ./0:0:1:0/name > > It is relatively easy to write user space tools to show > this information: > # lsscsi -n > [0:0:1:0] disk FUJITSU MAM3184MP 0106 /dev/sda > name: SFUJITSU MAM3184MP UKS0P2300CK0 > [1:0:4:0] disk IBM DNES-309170W SA30 /dev/sdb > name: SIBM DNES-309170W AJF98887 > > Each pair of lines links the transient topological and device > node name ("0:0:1:0" and "dev/sda" respectively) with a > (hopefully) invariant "name" for that device. > > So if that name was hashed there would be a reasonable mapping > from that name to the current Linux scsi disk device node name > (e.g. /dev/sda). So user space tools could work out the mapping > and provide the "memory" from one boot to the next (and across > the deletion and re-addition of HBA modules). > > Doug Gilbert
Doug,
I completly agree with what you said. One can write a user-space tool to create/re-create/update device node and try to keep device names consistent. I am sure people (Greg KH) are working on this.
All I am trying to do is, come out with a plan to do this for 2.6. We can do all the user-space stuff and make generic dynamic <major, minor> assignment and some how make the /dev/ nodes magically everytime rmmod/insmod or re-boot. There are lots of dependencies and players here. All these going to happen for 2.6 ? I would love to see this happen. But please, don't leave it in the middle. (leaving the device node mapping to user/admin). And also, how do we deal with booting/running 2.4 ?
If not, my patch is a fallback solution.
Thanks, Badari
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