Hi Vladislav, If I don't use the Scale-Out File Server, I don't have any issues with iSCSI speeds: if I directly connect the LUN(s) to the individual servers, I get 'full' speed - it just seems the Scale-Out File Server is causing the issue. Very strange of Microsoft (though not totally unexpected!). I can't find too much online about Scale-Out File Server, other than generic setup information.
Thanks! Respectfully, Tyler Nov 14, 2022, 9:20 AM by [email protected]: > Hi > > On Mon, 2022-11-14 at 15:00 +0100, Tyler Phillippe via Users wrote: > >> Good idea! I setup a RAM disk on both of those systems, let them sync, added >> it to the cluster. >> >> One thing I left out (which didn't hit me until yesterday as a possibility) >> is that I have the iSCSI LUN attached to two Windows servers that are acting >> as a Scale-Out File Server. When I copied a file over to the new RAMdisk LUN >> via Scale-Out File Server, I am still getting 10-20MB/s; however, when I >> create a large file to the underlying, shared DRBD on those CentOS machines, >> I am getting about 700+MB/s, which I watched via iostat. So, I guess it's >> the Scale-Out File Server causing the issue. Not sure why Microsoft and the >> Scale-Out File Server is causing the issue - guess Microsoft really doesn't >> like non-Microsoft backing disks >> >> > > > Not with Microsoft, but with overall iSCSI performance. For the older iSCSI > target - IET - I used to use the following settings: > InitialR2T=No > ImmediateData=Yes > MaxRecvDataSegmentLength=65536 > MaxXmitDataSegmentLength=65536 > MaxBurstLength=262144 > FirstBurstLength=131072 > MaxOutstandingR2T=2 > Wthreads=128 > QueuedCommands=32 > > Without that iSCSI LUNs were very slow independently of backing device speed. > Probably LIO provides a way to set them up as well. > > Best, > Vladislav > > >> Does anyone have any experience with that, perhaps? Thanks!! >> >> Respectfully, >> Tyler >> >> >> >> Nov 14, 2022, 2:30 AM by [email protected]: >> >>> Hi! >>> >>> If you have planty of RAM you could configure an iSCSI disk using a ram >>> disk and try how much I/O you get from there. >>> Maybe you issue is not-su-much DRBD related. However when my local MD-RAID1 >>> resyncs with about 120MB/s (spinning disks), the system also is hardly >>> usable. >>> >>> Regards, >>> Ulrich >>> >>>>>> Tyler Phillippe via Users <[email protected]> schrieb am 13.11.2022 >>>>>> um >>>>>> >>> 19:26 in Nachricht <[email protected]>: >>> >>>> Hello all, >>>> >>>> I have setup a Linux cluster on 2x CentOS 8 Stream machines - it has >>>> resources to manage a dual primary, GFS2 DRBD setup. DRBD and the cluster >>>> have a diskless witness. Everything works fine - I have the dual primary >>>> DRBD >>>> working and it is able to present an iSCSI LUN out to my LAN. However, the >>>> DRBD write speed is terrible. The backing DRBD disks (HDD) are RAID10 >>>> using >>>> mdadm and they (re)sync at around 150MB/s. DRBD verify has been limited to >>>> 100MB/s, but left untethered, it will get to around 140MB/s. If I write >>>> data >>>> to the iSCSI LUN, I only get about 10-15MB/s. Here's the DRBD >>>> global_common.conf - these are exactly the same on both machines: >>>> >>>> global { >>>> usage-count no; >>>> udev-always-use-vnr; >>>> } >>>> >>>> common { >>>> handlers { >>>> } >>>> >>>> startup { >>>> wfc-timeout 5; >>>> degr-wfc-timeout 5; >>>> } >>>> >>>> options { >>>> auto-promote yes; >>>> quorum 1; >>>> on-no-data-accessible suspend-io; >>>> on-no-quorum suspend-io; >>>> } >>>> >>>> disk { >>>> al-extents 4096; >>>> al-updates yes; >>>> no-disk-barrier; >>>> disk-flushes; >>>> on-io-error detach; >>>> c-plan-ahead 0; >>>> resync-rate 100M; >>>> } >>>> >>>> net { >>>> protocol C; >>>> allow-two-primaries yes; >>>> cram-hmac-alg "sha256"; >>>> csums-alg "sha256"; >>>> verify-alg "sha256"; >>>> shared-secret "secret123"; >>>> max-buffers 36864; >>>> rcvbuf-size 5242880; >>>> sndbuf-size 5242880; >>>> } >>>> } >>>> >>>> Respectfully, >>>> Tyler >>>> >>> >>> >>> >>> >>> _______________________________________________ >>> Manage your subscription: >>> https://lists.clusterlabs.org/mailman/listinfo/users >>> >>> ClusterLabs home: https://www.clusterlabs.org/ >>> >> >> _______________________________________________ >> Manage your subscription: >> https://lists.clusterlabs.org/mailman/listinfo/users >> >> ClusterLabs home: >> https://www.clusterlabs.org/ >> > > >
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