My thoughts inline:

On Tue, Jun 17, 2008 at 5:40 PM, HIMANSHU <[EMAIL PROTECTED]> wrote:

> 1.
> You say that performance figures are this..
> single iSCSI session:
>    * 450MB/s Read and 450 MB/s Write for 64KB block
>    * 510 MB/s Read and 550 MB/s Write for 256KB block
>    * 65,000 IOPS - 1K, 58,000 IOPS - 2K, 50,000 IOPS with 4KB Read
> two iSCSI sessions:
>    * 550 MB/s Read and 810 MB/s Write for 256KB block
>    * 75,000 IOPS for 1K block
> How can we measure figures on our machine?
> "Iometer" , "disktest" are few tools available for that.
> Can u suggest any good one?
> -------------------------------------------------------------------------------------------------------------------------------
> 2.
> When Initiator can get access to disk from target,What all
> applications user can have?Means besides Storage,what is the use of
> this Disk?

[Dheeraj] Its just like a disk. Apart from storage, a disk can also be used
as a lock, albeit via a filesystem using file locks.
Similarly using scsi reservations, I believe it could be used as a lock.

> --------------------------------------------------------------------------------------------------------------------------------
> 3.
> If one initiator is logged in to target "iqn.
>" which is 1 GB.
> It thus have access to it,it partitions it using "fdisk".Creates file
> system using "mkfs".mounts it and writes 300 MB data on it.
> If second initiator machine logs in to the same target,it can view all
> the 300 MB data written by 1st initiator if 2nd initiator doesn't
> format that disk after login. 2nd initiator only mounts the logged in
> disk and thus had access to all the 300 MB data. Is it ethical?
> Should we allow same target to be shared by multiple initiators at the
> same time?
> What will be the pros and cons?

{DHeeraj]:Unless there are more than one writers, the data can be accessed
without  inconsistency.
However in case the LU is to be shared among hosts, they must form a
group(aka cluster) and reserve the LU before accessing it.
SCSI provides persistent reserve and release commands to achieve this.

> I think,we need to handle synchronization issues there.Data written by
> 1st initiator shouldn't be deleted by others and all......

Or Data from 1st initiator should not be visible/accessible to others.

> What approach looks more ethical and practical?
> -------------------------------------------------------------------------------------------------------------------------------
> >

Simplicity of character is the natural result of profound thought.

You received this message because you are subscribed to the Google Groups 
"open-iscsi" group.
To post to this group, send email to
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at

Reply via email to