hugetlbfs

hugetlbfs

[Yunfeng Zhao]

Hi,
I meet problem to get hugetlbfs work on my test box.
If i added "--mem-path" to qemu, the guest will always fail to boot with 
the error messages below printed on qemu console:
###########################################
ata0 master: ATA-0 Hard-Disk (  0 MBytes)
ata1 master: ATAPI-0 Device

Booting from Hard Disk .....
Booting from Hard Disk failed: could not read the boot disk
##########################################

And I checked my system, hugepages has been enabled.
[root@vt-dp8 ~]# grep -i huge /proc/meminfo
HugePages_Total:   100
HugePages_Free:     96
HugePages_Rsvd:      0
Hugepagesize:     2048 kB

[root@vt-dp8 ~]# mount
/dev/sda1 on / type ext3 (rw)
none on /dev/shm type tmpfs (rw,size=4G)
nodev on /hugepages type hugetlbfs (rw)
/dev/sda3 on /share type ext2 (rw)
/dev/sda2 on /mnt/sda2 type ext3 (rw)

The command i am using:
qemu -m 256 -monitor pty -net 
nic,macaddr=00:16:3e:48:d4:aa,model=rtl8139 -net 
tap,script=/etc/kvm/qemu-ifup -hda /dev/sda --mem-path /hugepages/

If I remove "--mem-path", the guest can be booted up.


Anybody knows what the problem is?

thanks
Yunfeng

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Re: hugetlbfs

[Dor Laor]

On Wed, 2008-04-09 at 17:26 +0800, Yunfeng Zhao wrote:
> Hi,
> I meet problem to get hugetlbfs work on my test box.
> If i added "--mem-path" to qemu, the guest will always fail to boot with 
> the error messages below printed on qemu console:
> ###########################################
> ata0 master: ATA-0 Hard-Disk (  0 MBytes)
> ata1 master: ATAPI-0 Device
> 
> Booting from Hard Disk .....
> Booting from Hard Disk failed: could not read the boot disk
> ##########################################
> 
> And I checked my system, hugepages has been enabled.
> [root@vt-dp8 ~]# grep -i huge /proc/meminfo
> HugePages_Total:   100
> HugePages_Free:     96
> HugePages_Rsvd:      0
> Hugepagesize:     2048 kB
> 
> [root@vt-dp8 ~]# mount
> /dev/sda1 on / type ext3 (rw)
> none on /dev/shm type tmpfs (rw,size=4G)
> nodev on /hugepages type hugetlbfs (rw)
> /dev/sda3 on /share type ext2 (rw)
> /dev/sda2 on /mnt/sda2 type ext3 (rw)
> 
> The command i am using:
> qemu -m 256 -monitor pty -net 
> nic,macaddr=00:16:3e:48:d4:aa,model=rtl8139 -net 
> tap,script=/etc/kvm/qemu-ifup -hda /dev/sda --mem-path /hugepages/
> 
> If I remove "--mem-path", the guest can be booted up.
> 

You have only 96 free 2MB pages, it is less then 256M you asked for the
VM.
you can do 'echo 200 > /proc/sys/vm/nr_hugepages'
HTH,
Dor

> 
> Anybody knows what the problem is?
> 
> thanks
> Yunfeng
> 
> -------------------------------------------------------------------------
> This SF.net email is sponsored by the 2008 JavaOne(SM) Conference 
> Don't miss this year's exciting event. There's still time to save $100. 
> Use priority code J8TL2D2. 
> http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone
> _______________________________________________
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> kvm-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/kvm-devel


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Re: hugetlbfs

[Yunfeng Zhao]

Dor Laor wrote:
> On Wed, 2008-04-09 at 17:26 +0800, Yunfeng Zhao wrote:
>   
>> Hi,
>> I meet problem to get hugetlbfs work on my test box.
>> If i added "--mem-path" to qemu, the guest will always fail to boot with 
>> the error messages below printed on qemu console:
>> ###########################################
>> ata0 master: ATA-0 Hard-Disk (  0 MBytes)
>> ata1 master: ATAPI-0 Device
>>
>> Booting from Hard Disk .....
>> Booting from Hard Disk failed: could not read the boot disk
>> ##########################################
>>
>> And I checked my system, hugepages has been enabled.
>> [root@vt-dp8 ~]# grep -i huge /proc/meminfo
>> HugePages_Total:   100
>> HugePages_Free:     96
>> HugePages_Rsvd:      0
>> Hugepagesize:     2048 kB
>>
>> [root@vt-dp8 ~]# mount
>> /dev/sda1 on / type ext3 (rw)
>> none on /dev/shm type tmpfs (rw,size=4G)
>> nodev on /hugepages type hugetlbfs (rw)
>> /dev/sda3 on /share type ext2 (rw)
>> /dev/sda2 on /mnt/sda2 type ext3 (rw)
>>
>> The command i am using:
>> qemu -m 256 -monitor pty -net 
>> nic,macaddr=00:16:3e:48:d4:aa,model=rtl8139 -net 
>> tap,script=/etc/kvm/qemu-ifup -hda /dev/sda --mem-path /hugepages/
>>
>> If I remove "--mem-path", the guest can be booted up.
>>
>>     
>
> You have only 96 free 2MB pages, it is less then 256M you asked for the
> VM.
> you can do 'echo 200 > /proc/sys/vm/nr_hugepages'
> HTH,
> Dor
>   
I tried to enable 512MB pages, and then to boot 256M guest. It still 
fails with the same error.

thanks
Yunfeng
>   
>> Anybody knows what the problem is?
>>
>> thanks
>> Yunfeng
>>
>> -------------------------------------------------------------------------
>> This SF.net email is sponsored by the 2008 JavaOne(SM) Conference 
>> Don't miss this year's exciting event. There's still time to save $100. 
>> Use priority code J8TL2D2. 
>> http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone
>> _______________________________________________
>> kvm-devel mailing list
>> kvm-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/kvm-devel
>>     
>
>
>   


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