[zfs-discuss] General Questions on ARC & L2ARC

Pandu Poluan pandu at poluan.info
Thu Aug 29 00:57:25 EDT 2013

Hello, people!

I'm quite new to ZFS, but even then already love it to death -- had some 
brushes with disaster that were averted by a timely 'zfs rollback', and now 
my boss loves ZFS, too :-)

I hope I don't come across as an annoying newb, but I have several 
questions around ARC & L2ARC.

1. Since ZFS' ARC might fell victim to Linux memory fragmentation [1], what 
if I just set zfs_arc_min = zfs_arc_max ? Won't that cause the ARC to stay 
at a fixed size, hence not affected by memory fragmentation issue as the 
zfs module can allocate the ARC memory since boot?

2. I have also read several times in this forum/group about employing ZRAM 
for L2ARC. On benefit mentioned in [1] is that L2ARC size is constant, so 
it will not cause 'gotchas' like what happens when ARC baloons in size. But 
I've searched and yet to find a comprehensive analysis on this strategy's 
benefits vs drawbacks. Can someone point me to such resource and/or provide 
me with one?

Thank you very much for your assistance.

[1] "ZFS consuming twice ARC's size and crashing system" 


To unsubscribe from this group and stop receiving emails from it, send an email to zfs-discuss+unsubscribe at zfsonlinux.org.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.zfsonlinux.org/pipermail/zfs-discuss/attachments/20130828/69c31e6c/attachment.html>

More information about the zfs-discuss mailing list