drbd-user March 2010 archive
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drbd-user: [DRBD-user] vSphere MPIO with scst/drbd in dual prima

[DRBD-user] vSphere MPIO with scst/drbd in dual primary mode. WAS: Re: [Scst-devel] R: Re: virt_dev->usn randomly generated!?

From: Matteo Tescione <matteo_at_nospam>
Date: Sat Mar 06 2010 - 18:43:35 GMT
To: Brian Jared <bjared@ethosprime.com>

Hi folks,
after a little bit of experimenting I SUCCESFULLY created an drbd active/active cluster with scst/iscsi exported to round-robin vsphere initiator.

configuration is 2 virtual machines with centos5-64 linux-2.6.33 patched and drbd8.3.7. Initiators are vSphere Software iscsi initiator.
Relevant config in drbd is net section, allow-two-primaries.
Relevant config in scst.conf is:

DEVICE rmnet-devel,/dev/drbd0,NV_CACHE,512

[ASSIGNMENT Default_iqn.2010-02.com.scst:RMnet-devel]
#DEVICE <device name>,<lun
DEVICE rmnet-devel,0

Note that I'm using the same scst.conf and iscsi-scstd.conf in both targets.
The vSphere initiators are seeing 2 paths for 1 device, switched to Round-robin.
Since the targets are running virtual with no real hardware, i have no idea at the moment of what kind of performance increase it could bring.
Vlad, what do you think about? is fileio the best choice here?

Hope this helps,
-- matteo ----- Messaggio originale ----- Da: "Brian Jared" <bjared@ethosprime.com> A: "Vladislav Bolkhovitin" <vst@vlnb.net> Cc: scst-devel@lists.sourceforge.net Inviato: venerdì 5 marzo 2010 19.54.51 (GMT+0100) Europe/Berlin Oggetto: [SPAM?]Re: [Scst-devel] R: Re: virt_dev->usn randomly generated!? That was the intention...but the scst.conf file on the other machine looks a lot different. There's no [HANDLER vdisk] section, and only GROUP and ASSIGNMENT sections for the Default_iqn.x.x.x ... I'm guessing that's why they didn't work? Below is the config that is on the other host, but I can't believe it's so different from the other one... It's been a while, so I am not sure what all I tried back then, or why this is so drastically different. --Brian # Automatically generated by SCST Configurator v1.0.6. [HANDLER disk] #DEVICE <H:C:I:L> [HANDLER disk_perf] #DEVICE <H:C:I:L> [GROUP Default] #USER <user wwn> [GROUP Default_iqn.2000-01.com.ethosprime:nas2.drbd0.bucket01] #USER <user wwn> [GROUP Default_iqn.2000-01.com.ethosprime:nas2.drbd1.bucket02] #USER <user wwn> [GROUP Default_iqn.2000-01.com.ethosprime:nas2.drbd2.bucket03] #USER <user wwn> [GROUP Default_iqn.2000-01.com.ethosprime:nas2.drbd3.bucket04] #USER <user wwn> [ASSIGNMENT Default] #DEVICE <device name>,<lun> [ASSIGNMENT Default_iqn.2000-01.com.ethosprime:nas2.drbd0.bucket01] #DEVICE <device name>,<lun> DEVICE 0:2:1:0,0 [ASSIGNMENT Default_iqn.2000-01.com.ethosprime:nas2.drbd1.bucket02] #DEVICE <device name>,<lun> DEVICE 0:2:2:0,0 [ASSIGNMENT Default_iqn.2000-01.com.ethosprime:nas2.drbd2.bucket03] #DEVICE <device name>,<lun> DEVICE 1:2:0:0,0 [ASSIGNMENT Default_iqn.2000-01.com.ethosprime:nas2.drbd3.bucket04] #DEVICE <device name>,<lun> DEVICE 1:2:1:0,0 [TARGETS enable] #HOST <wwn identifier> [TARGETS disable] #HOST <wwn identifier> ----- Original Message ----- From: "Vladislav Bolkhovitin" <vst@vlnb.net> To: "Brian Jared" <bjared@ethosprime.com> Cc: scst-devel@lists.sourceforge.net Sent: Friday, March 5, 2010 12:58:48 PM GMT -05:00 US/Canada Eastern Subject: Re: [Scst-devel] R: Re: virt_dev->usn randomly generated!? Brian Jared, on 03/05/2010 06:57 PM wrote: > I found my old config. For some reason I thought I deleted all of the old > scst stuff. > > This is what my config looked like before I gave up. Those DEVICE lines > appear just as you mentioned. So, what did I do wrong? Used the same file and scst_vdisk_ID on both hosts? > --Brian > > # Automatically generated by SCST Configurator v1.0.6. > > [HANDLER vdisk] > #DEVICE <vdisk name>,<device path>,<options>,<block size> > DEVICE bucket01,/dev/drbd0,NV_CACHE,512 > DEVICE bucket02,/dev/drbd1,NV_CACHE,512 > DEVICE bucket03,/dev/drbd2,NV_CACHE,512 > DEVICE bucket04,/dev/drbd3,NV_CACHE,512 > > [HANDLER vcdrom] > #DEVICE <vdisk name>,<device path> > > [GROUP Bucket01] > #USER <user wwn> > > [GROUP Bucket01_iqn.2000-01.com.ethosprime:nas1.drbd0.bucket01] > #USER <user wwn> > > [GROUP Bucket02] > #USER <user wwn> > > [GROUP Bucket02_iqn.2000-01.com.ethosprime:nas1.drbd1.bucket02] > #USER <user wwn> > > [GROUP Bucket03] > #USER <user wwn> > > [GROUP Bucket03_iqn.2000-01.com.ethosprime:nas1.drbd2.bucket03] > #USER <user wwn> > > [GROUP Bucket04] > #USER <user wwn> > > [GROUP Bucket04_iqn.2000-01.com.ethosprime:nas1.drbd3.bucket04] > #USER <user wwn> > > [GROUP Default] > #USER <user wwn> > > [ASSIGNMENT Bucket01] > #DEVICE <device name>,<lun> > > [ASSIGNMENT Bucket01_iqn.2000-01.com.ethosprime:nas1.drbd0.bucket01] > #DEVICE <device name>,<lun> > DEVICE bucket01,0 > > [ASSIGNMENT Bucket02] > #DEVICE <device name>,<lun> > > [ASSIGNMENT Bucket02_iqn.2000-01.com.ethosprime:nas1.drbd1.bucket02] > #DEVICE <device name>,<lun> > DEVICE bucket02,0 > > [ASSIGNMENT Bucket03] > #DEVICE <device name>,<lun> > > [ASSIGNMENT Bucket03_iqn.2000-01.com.ethosprime:nas1.drbd2.bucket03] > #DEVICE <device name>,<lun> > DEVICE bucket03,0 > > [ASSIGNMENT Bucket04] > #DEVICE <device name>,<lun> > > [ASSIGNMENT Bucket04_iqn.2000-01.com.ethosprime:nas1.drbd3.bucket04] > #DEVICE <device name>,<lun> > DEVICE bucket04,0 > > [ASSIGNMENT Default] > #DEVICE <device name>,<lun> > > [TARGETS enable] > #HOST <wwn identifier> > > [TARGETS disable] > #HOST <wwn identifier> > > > > ----- Original Message ----- > From: "Vladislav Bolkhovitin" <vst@vlnb.net> > To: "Brian Jared" <bjared@ethosprime.com> > Cc: scst-devel@lists.sourceforge.net, "Matteo Tescione" <matteo@rmnet.it> > Sent: Friday, March 5, 2010 8:44:54 AM GMT -05:00 US/Canada Eastern > Subject: Re: [Scst-devel] R: Re: virt_dev->usn randomly generated!? > > Brian Jared, on 03/04/2010 04:41 AM wrote: >> Maybe you could give an example of a config that would generate >> the same SN from two targets that MUST be different. I'm very curious, >> as I couldn't find any documentation on this. >> >> It's my understanding that targets must all be uniquely named, and unique >> target names pushed through a static (randomly generated) array will also >> be unique, and thus vSphere4 won't see them as being the same LUN on >> different hosts. >> >> Again, the problem is that my only interface appears to be my naming of the >> iSCSI target LUN, which has to be unique...so...they'll always appear like >> 4 unique disks, and not two disks with two paths each. >> >> An example config might clear this up. I'm still wondering how this works. > > In SCST all devices have names. Matteo gave you example: > > DEVICE devel-datastore,/dev/drbd0,NV_CACHE,512 > > Here "devel-datastore" is the name. From this name and _only from it_ > the ID/USN is generated. > > Vlad > -- ; Brian Jared <bjared@ethosprime.com> : Ethos Prime Engineer : http://www.ethosprime.com : Cell: 317.201.9036 ------------------------------------------------------------------------------ Download Intel&#174; Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Scst-devel mailing list Scst-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/scst-devel _______________________________________________ drbd-user mailing list drbd-user@lists.linbit.com http://lists.linbit.com/mailman/listinfo/drbd-user