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Native ZFS for Linux
http://wiki.github.com/behlendorf/zfs/
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XEN: zvol disappear on reboot #100

Open tentonwire opened 13 years ago

tentonwire commented 13 years ago

Compiled against and using on xenified 2.6.32-30 amd64 pvops dom0 kernel on xen 4.0.1-2, two major bugs with zvols.

1) zvol /dev entries disappear on reboot. Can be regenerated with zfs rename; however, temporary name remains as dev entry. For example, renaming tank/test to tank/test1 and back generates /dev/tank/test and /dev/tank/test1.

2) zvol performance is horrible. Write performance (dd iso to zvol block device) is approximately 10% of write performance when dding to file on zfs file system. Read is more sporadic, anywhere from 25-50% that of a file.

Moved the second to a separate issue at #107.

nkhare commented 13 years ago

First issue is reported by other users as well. Unfortunately we are not able to re-produce it easily. Can you share the steps by which you hit this issue.

I see some better numbers than you while doing the write on zvol. We will be doing more investigation on that and will update you.

tentonwire commented 13 years ago

The first issue is fairly easy to test.

root@zeno# zpool create tank raidz1 /dev/sdb /dev/sdc /dev/sdd root@zeno# zfs create -V 10G tank/test root@zeno# ls /dev/tank/test # exists reboot root@zeno# ls /dev/tank/test # doesn't exist root@zeno# zfs list # tank/test exists root@zeno# zfs rename tank/test tank/test1 root@zeno# zfs rename tank/test1 tank/test root@zeno# ls /dev/tank/test* # both test and test1 are there.

Whoops, I accidentally closed this issue. If someone could reopen it, that would be great.

fajarnugraha commented 13 years ago

This issue is fixed upstream by https://github.com/behlendorf/zfs/commit/d56744

nkhare commented 13 years ago

Thanks fajarnugraha. I have pushed the changes after looking at the commit mentioned by you.