Re: LTO-4 iSCSI performance less than expected ...
Of course it turns out the data for that test was highly compressible. So the actual speed over the network was around 33-40MB/s Rumour has it that the Jumbo Frame capable ethernet cards arrive today. I'll let U know if that changes anything. Dave -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
Well that was interesting - I booted up the application I used for BU of my Windows systems and used that to backup this Linux box over the network to the iSCSI connected drive. Result using SW compression I was getting about 90-130MB/s So confused why dd etc. was so darn slow ... Dave On Saturday, 15 April 2017 11:05:25 UTC+1, david.p...@perdrix.co.uk wrote: > > Before doing the dd I issued: > > mt-st -f /dev/st0l setblk 65536 stsetoptions 0x8000 > > which was happily accepted, but it made no difference to the throughput. > > Looking at the server hosting the tape, the network was only running at > about 37% capacity (32MB/s). > > Zipping the output of dd and writing to the non-compression device killed > throughput (not enough CPU grunt to keep the pipeline fed :( > > I may need to get some new network cards that support jumbo frames! > > Dave > -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
Before doing the dd I issued: mt-st -f /dev/st0l setblk 65536 stsetoptions 0x8000 which was happily accepted, but it made no difference to the throughput. Looking at the server hosting the tape, the network was only running at about 37% capacity (32MB/s). Zipping the output of dd and writing to the non-compression device killed throughput (not enough CPU grunt to keep the pipeline fed :( I may need to get some new network cards that support jumbo frames! Dave -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
Thanks Lee, It would appear that stoptions and setstoptiosn are synonyms. 35 is the command code for MTWEOFI not the mask for enabling it as you say. I misread the header file. So yes 0x8000 seems to be correct. I'll give it a try. Dave -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
On Friday, April 14, 2017 at 4:31:05 AM UTC-7, david.partri...@perdrix.co.uk wrote: > > Let's try another tack. > > Will "mt-st -f /dev/st0l /stoptions 35" turn on MTWEOFI? > > Dave > Hi Dave: I don't know. I download mt-st, which I've never seen before, and perhaps you mean: > # mt-st -f setstoptions But the flag value is not "35". I believe you would want the value of MT_ST_NOWAIT_EOF, which is 0x8000. If I had a tape drive and more time I'd test it, but I do not. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
Let's try another tack. Will "mt-st -f /dev/st0l /stoptions 35" turn on MTWEOFI? Dave -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
RE: LTO-4 iSCSI performance less than expected ...
Hmmm I couldn’t find anything about this in the stinit docs. Dave From: open-iscsi@googlegroups.com [mailto:open-iscsi@googlegroups.com] On Behalf Of The Lee-Man Sent: 03 April 2017 20:05 To: open-iscsi Subject: Re: LTO-4 iSCSI performance less than expected ... On Friday, March 31, 2017 at 2:23:30 PM UTC-7, david.partri...@perdrix.co.uk wrote: I don't know? How do I find out? Should I have it set? Have you set the Write Immediate Filemark option for the st driver? There are a couple of ways to enable writing immediate filemarks in the st driver. One is to use the MTWEOFI ioctl(). If you have access to the source code for your application, this is a good way to go. But I added a user-settable option with kernel commit c743e44fbb1f8668941e83de07662b1ecd33d083. It allows you to tell the st driver to write immediate file marks by setting a sysfs attribute. -- -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
On Friday, March 31, 2017 at 2:23:30 PM UTC-7, david.partri...@perdrix.co.uk wrote: > > I don't know? How do I find out? Should I have it set? > >> >> Have you set the Write Immediate Filemark option for the st driver? >> > There are a couple of ways to enable writing immediate filemarks in the st driver. One is to use the MTWEOFI ioctl(). If you have access to the source code for your application, this is a good way to go. But I added a user-settable option with kernel commit c743e44fbb1f8668941e83de07662b1ecd33d083. It allows you to tell the st driver to write immediate file marks by setting a sysfs attribute. -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
I don't know? How do I find out? Should I have it set? > > Have you set the Write Immediate Filemark option for the st driver? > -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
On Monday, March 27, 2017 at 9:03:59 AM UTC-7, david.partri...@perdrix.co.uk wrote: > > I'm connecting my Linux server to an LTO-4 tape drive over a 1 gigabit LAN > with very little other activity. > > Doing some hand waving, I guess that I should allow ten bits per byte and > a protocol overhead of around 40%. That gets me to about 60MB/s which I > know is about half what the drive is capable of. > > However what I'm seeing is a consistent throughput of about 30MB/s which > is quite a lot slower that I'd expect. > > The processor is an Intel Atom D525 1.80Ghz four core processor with 4GB > RAM. > > The drive I'm backing up is a SATA SSD. > > The backup is run thus: > > sudo mt-st -f /dev/st0l setblk 65536 > sudo dd bs=64k if=/dev/sdb | mbuffer -s 65536 -m -m 50% -P 80 -o /dev/st0l > > Is what I'm seeing pretty much the norm, or is there something I can do to > get better throughput? > > Thanks in advance for any assistance you can provide. > Dave > > > Have you set the Write Immediate Filemark option for the st driver? -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
Re: LTO-4 iSCSI performance less than expected ...
Hi there, Uli, Yes I did listen to the drive - no it wasn't shoe-shining. DD direct gave a slightly slower throughput. Dave -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To unsubscribe from this group and stop receiving emails from it, send an email to open-iscsi+unsubscr...@googlegroups.com. To post to this group, send email to open-iscsi@googlegroups.com. Visit this group at https://groups.google.com/group/open-iscsi. For more options, visit https://groups.google.com/d/optout.
