RE: [Lsf10-pc] Suggested topic for August LSF summit event (SCSI/FS/MM)

[<Mark_Ruder@Dell.com>]

Resending as text.

SAN Storage Features   affecting the Kernel

● ISCSI Array Multipathing
● LUN split over several arrays. Separate data connection to
each array for parts of the LUN
● Requires kernel iSCSI path selector module per-vendor
● Thin Provisioning
● Actual allocated storage is less than requested size (akin to
sparse files)
● Must handle alerts when TP threshholds reached
– CHECK CONDITION raised on writes
– LUN goes read-only if space exhausted
● T10 work ongoing to standardize interfaces and behavior

● TRIM / UNMAP / WRITE_SAME
● Inform storage that these blocks are no longer needed
● Useful on SANs, not just SSDs
● T10 & T13 standards proposals in flux
● XCOPY – Array-level block copy, perhaps copy-on-write
● Copy blocks w/o incuring network and CPU overhead
● VFS function?
● T10 standard already (SCSI Extended Copy)
 
SAN Storage Features needing basic CLI work
 
● Multi-IQN – iSCSI IQNs are assigned to Guest VMs
● Implemented in iscsi-initiator-utils today, thank you!
● VM Guest boot from iSCSI
● Requires iSCSI Initiator in VM BIOS
● Fedora 11 KVM will load gPXE iSCSI Option ROMs, thank
you!
● Array-based LUN snapshots
● ioctl(FIFREEZE) added Jan 09 by Takashi Sato of NEC,
thank you!
● Need CLI to freeze file system, issue array-based snapshot
command, and thaw file system



Thanks,
Mark



-----Original Message-----
From: James Bottomley [mailto:James.Bottomley@HansenPartnership.com] 
Sent: Friday, June 18, 2010 10:12 AM
To: Ruder, Mark
Cc: lsf10-pc@lists.linuxfoundation.org; linux-fsdevel@vger.kernel.org; linux-mm@kvack.org; linux-scsi@vger.kernel.org
Subject: Re: [Lsf10-pc] Suggested topic for August LSF summit event (SCSI/FS/MM)

On Fri, 2010-06-18 at 09:55 -0500, Mark_Ruder@Dell.com wrote:
> I was asked to share suggested topics that we would be interested in
> being discussed in the upcoming LSF Summit even in early August.
> Rather that re-typing all of them into this email, I’ve attached a
> slide deck developed by Matt Domsch in Dell’s CTO office as a starting
> point. It is a bit dated, but we feel that topics are still relevant
> to us.

We got this on the PC lists, but all of the other mailing lists will
have discarded it sight unseen (enforcing plain text only and nothing
other than text/plain attachments is a standard list spam mitigation
technique).  Could you summarise as text (you can just go to the outline
view and paste everything into a text window).

James