<html><head><style type='text/css'>p { margin: 0; }</style></head><body><div style='font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000'>I can't seem to find any option to disable disk caching in Xen. Perhaps it has to do with the fact that Xen shares it's disk driver with the dom0, because of paravirtualized drivers? I can see that you too use the virtio and not emu, so I guess that shouldn't be an issue, but I don't know.<br><br><br><hr id="zwchr"><blockquote style="border-left:2px solid rgb(16, 16, 255);margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><b>From: </b>"Marcel Kraan" <marcel@kraan.net><br><b>To: </b>"Wiebe Cazemier" <wiebe@halfgaar.net><br><b>Cc: </b>drbd-user@lists.linbit.com<br><b>Sent: </b>Thursday, 31 May, 2012 8:19:31 AM<br><b>Subject: </b>Re: [DRBD-user] Xen DomU on DRBD device: barrier errors<br><br>They say that the original host does the caching.<div>In KVM it's easy to turndown the cache</div><div>I use libvirtd and qemu-kvm to start the vm's</div><div>see attachement.</div><div><br></div><div><br></div><div><br></div><div><br></div><div><img id="8ee2b3bb-7e9b-41b8-aa17-a87d0fece745" src="cid:E97F3612-D763-498E-AFC1-72B2D0C8BC95" height="666" width="1190"><br><div><div>On 31 mei 2012, at 08:07, Wiebe Cazemier wrote:</div><br class="Apple-interchange-newline"><blockquote><div><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); ">Hi,<br><br>How did you turn off the cache? And how much did that influence performance?<br><br>I'll try, but I'd rather find a solution that doesn't involve turning off the cache.<br><br>Wiebe<br><br><br><hr id="zwchr"><blockquote style="border-left-width: 2px; border-left-style: solid; border-left-color: rgb(16, 16, 255); margin-left: 5px; padding-left: 5px; color: rgb(0, 0, 0); font-weight: normal; font-style: normal; text-decoration: none; font-family: Helvetica, Arial, sans-serif; font-size: 12pt; "><b>From:<span class="Apple-converted-space"> </span></b>"Marcel Kraan" <<a href="mailto:marcel@kraan.net" target="_blank">marcel@kraan.net</a>><br><b>To:<span class="Apple-converted-space"> </span></b>"Wiebe Cazemier" <<a href="mailto:wiebe@halfgaar.net" target="_blank">wiebe@halfgaar.net</a>><br><b>Cc:<span class="Apple-converted-space"> </span></b><a href="mailto:drbd-user@lists.linbit.com" target="_blank">drbd-user@lists.linbit.com</a><br><b>Sent:<span class="Apple-converted-space"> </span></b>Thursday, 31 May, 2012 7:58:10 AM<br><b>Subject:<span class="Apple-converted-space"> </span></b>Re: [DRBD-user] Xen DomU on DRBD device: barrier errors<br><br>Helllo Wiebe,<div><br></div><div>I had that also.</div><div>But when i turned down the cache on the storage, and the other vm clients the error was gone.</div><div>So no cache on the VM's and it worked very good. </div><div><br></div><div><br></div><div>marcel</div><div><br></div><div><br><div><div>On 30 mei 2012, at 17:13, Wiebe Cazemier wrote:</div><br class="Apple-interchange-newline"><blockquote><span class="Apple-style-span" style="border-collapse: separate; font-family: Calibri; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0); ">Hi, <br><br>I'm testing setting up a Xen DomU with a DRBD storage for easy failover. Most of the time, immediately after booting the DomU, I get an IO error:<br><br><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.153370] EXT3-fs (xvda2): using internal journal</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.277115] ip_tables: (C) 2000-2006 Netfilter Core Team</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.336014] nf_conntrack version 0.5.0 (3899 buckets, 15596 max)</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.515604] init: failsafe main process (397) killed by TERM signal</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.801589] blkfront: barrier: write xvda2 op failed</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.801597] blkfront: xvda2: barrier or flush: disabled</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.801611] end_request: I/O error, dev xvda2, sector 52171168</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.801630] end_request: I/O error, dev xvda2, sector 52171168</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.801642] Buffer I/O error on device xvda2, logical block 6521396</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.801652] lost page write due to I/O error on xvda2</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.801755] Aborting journal on device xvda2.</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.804415] EXT3-fs (xvda2): error: ext3_journal_start_sb: Detected aborted journal</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.804434] EXT3-fs (xvda2): error: remounting filesystem read-only</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 3.814754] journal commit I/O error</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 6.973831] init: udev-fallback-graphics main process (538) terminated with status 1</span><br style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: arial, helvetica, sans-serif; color: rgb(0, 0, 153); ">[ 6.992267] init: plymouth-splash main process (546) terminated with status 1</span><br><br>The manpage of drbdsetup says that LVM (which I use) doesn't support barriers (better known as "tagged command queuing" or "native command queuing"), so I configured the DRBD device not to use barriers. This can be seen in /proc/drbd (by "wo:f, meaning flush, the next method drbd chooses after barrier):<br><br><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> 3: cs:Connected ro:Primary/Secondary ds:UpToDate/UpToDate C r----</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> ns:2160152 nr:520204 dw:2680344 dr:2678107 al:3549 bm:9183 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0</span><br><br>And on the other host:<br><br><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> 3: cs:Connected ro:Secondary/Primary ds:UpToDate/UpToDate C r----</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> ns:0 nr:2160152 dw:2160152 dr:0 al:0 bm:8052 lo:0 pe:0 ua:0 ap:0 ep:1 wo:f oos:0</span><br><br>I also enabled the option disable_sendpage, as per the DRBD docs:<br><br><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); ">cat /sys/module/drbd/parameters/disable_sendpage</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); ">Y</span><br><br>I also tried adding barriers=0 to fstab as mount option. Still it says:<br><br><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); ">[ 58.603896] blkfront: barrier: write xvda2 op failed</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); ">[ 58.603903] blkfront: xvda2: barrier or flush: disabled</span><br><br>I don't even know if ext3 has a nobarrier option, but it does seem to work. But, because only one of my storage systems is battery backed, it would not be smart.<br><br>Why does it still compain about barriers when I disabled that?<br><br>Both hosts are:<br><br>Debian: 6.0.4<br>uname -a: Linux 2.6.32-5-xen-amd64<br>drbd: 8.3.7<br>Xen: 4.0.1<br><br>Guest:<br><br>Ubuntu 12.04 LTS<br>uname -a: Linux 3.2.0-24-generic pvops<br><br>drbd resource:<br><br><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); ">resource drbdvm</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); ">{</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> meta-disk internal;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> device /dev/drbd3;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> startup</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> {</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # The timeout value when the last known state of the other side was available. 0 means infinite.</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> wfc-timeout 0;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # Timeout value when the last known state was disconnected. 0 means infinite.</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> degr-wfc-timeout 180;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> }</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> syncer</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> {</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # This is recommended only for low-bandwidth lines, to only send those</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # blocks which really have changed.</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> #csums-alg md5;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # Set to about half your net speed</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> rate 60M;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # It seems that this option moved to the 'net' section in drbd 8.4. (later release than Debian has currently)</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> verify-alg md5;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> }</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> net</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> {</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # The manpage says this is recommended only in pre-production (because of its performance), to determine</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # if your LAN card has a TCP checksum offloading bug.</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> #data-integrity-alg md5;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> }</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> disk</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> {</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # Detach causes the device to work over-the-network-only after the</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # underlying disk fails. Detach is not default for historical reasons, but is</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # recommended by the docs.</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # However, the Debian defaults in drbd.conf suggest the machine will reboot in that event...</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> on-io-error detach;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # LVM doesn't support barriers, so disabling it. It will revert to flush. Check wo: in /proc/drbd. If you don't disable it, you get IO errors.</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> no-disk-barrier;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> }</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> on host1</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> {</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # universe is a VG</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> disk /dev/universe/drbdvm-disk;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> address 10.0.0.1:7792;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> }</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> on host2</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> {</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> # universe is a VG</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> disk /dev/universe/drbdvm-disk;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> address 10.0.0.2:7792;</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "> }</span><br style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); "><span style="font-family: 'courier new', courier, monaco, monospace, sans-serif; color: rgb(0, 0, 153); ">}</span><br><br><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">In my test setup: the primary host's storage is 9650SE SATA-II RAID PCIe with battery. The secondary is software RAID1.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Isn't DRBD+Xen widely used? With these problems, it's not going to work.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Any help welcome.<br></div><br></div>_______________________________________________<br>drbd-user mailing list<br><a href="mailto:drbd-user@lists.linbit.com" target="_blank">drbd-user@lists.linbit.com</a><br><a href="http://lists.linbit.com/mailman/listinfo/drbd-user" target="_blank">http://lists.linbit.com/mailman/listinfo/drbd-user</a><br></div></span></blockquote></div><br></div></blockquote><br></div></div><br class="Apple-interchange-newline"></blockquote></div><br></div></blockquote><br></div></body></html>